San Marcos City Council
July 23, 2024

Appendix G
Storm Water Quality Management Plan (SWQMP)

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]

CITY OF SAN MARCOS

PRIORITY DEVELOPMENT PROJECT (PDP)

STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR

PACIFIC
[INSERT PERMIT APPLICATION NUMBERS]
Las Pos
as Road
San Marcos, CA 92078

ASSESSO
R'S PARCEL NUMBER(S):
219-222-01, 219-222-02, 219-222-03, 219-222-04
ENGINEER OF WORK:
_____________________
______________________________________________________________ William Lundstrom, RCE 61630
PREPARED FOR:

The Las Posas Project Owner LPV, LLC a Delaware
Limited Liability Company.
703 Palomar Airport Road, Suite 170
Carlssbad, CA 92011
760-944-7511
PDP SWQMP PREPARED BY:

Lundstrom Engineering & Surveying, Inc.
3333 Camino Del Rio South, Suite 330
San Diego, CA 92108
619-814-1220
DATE OF SWQMP:
02/16/2023
PLANS PREPARED BY:

Lundstrom Engineering & Surveying, Inc. 3333
Camino Del Rio South, Suite 330 San Diego, CA
92108
619-814-1220
City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
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City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]

TABLE OF CONTENTS

Acronym Sheet
PDP SWQMP Preparer's Certification Page
PDP SWQMP Project Owner's Certification Page
Submittal Record
Project Vicinity Map
FORM I-1 Applicability of Storm Water BMP Requirements
FORM I-2 Project Type Determination Checklist (Standard Project or PDP) FORM I-3B Site Information Checklist for PDPs
FORM I-4 Source Control BMP Checklist for All Development Projects FORM I-5 Site Design BMP Checklist for All Development Projects FORM I-6 Summary of PDP Structural BMPs
Attachment 1: Backup for PDP Pollutant Control BMPs
Attachment 1a: DMA Exhibit
Attachment 1b: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1c: Harvest and Use Feasibility Screening (when applicable) Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable) Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations Attachment 2: Backup for PDP Hydromodification Control Measures Attachment 2a: Hydromodification Management Exhibit
Attachment 2b: Management of Critical Coarse Sediment Yield Areas Attachment 2c: Geomorphic Assessment of Receiving Channels Attachment 2d: Flow Control Facility Design
Attachment 3: Structural BMP Maintenance Plan
Attachment 3a: B Structural BMP Maintenance Thresholds and Actions Attachment 3b: Draft Maintenance Agreement (when applicable) Attachment 4: Copy of Plan Sheets Showing Permanent Storm Water BMPs

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]

ACRONYMS

APN Assessor's Parcel Number
BMP Best Management Practice
HMP Hydromodification Management Plan
HSG Hydrologic Soil Group
MS4 Municipal Separate Storm Sewer System
N/A Not Applicable
NRCS Natural Resources Conservation Service
PDP Priority Development Project
PE Professional Engineer
SC Source Control
SD Site Design
SDRWQCB San Diego Regional Water Quality Control Board
SIC Standard Industrial Classification
SWQMP Storm Water Quality Management Plan

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]

PDP SWQMP PREPARER'S CERTIFICATION PAGE
Project
Name: Pacific
Permit Application Number:

PREPARER
'S CERTIFICATION
I hereby
declare that I am the Engineer in Responsible Charge of design of storm water best management practices (BMPs) for this project, and that I have exercised responsible charge over the design of the BMPs as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the PDP requirements of the [INSERT AGENCY NAME] BMP Design Manual, which is a design manual for compliance with local [INSERT AGENCY NAME] and regional MS4 Permit (California Regional Water Quality Control Board San Diego Region Order No. R9-2015-0100) requirements for storm water management.

I have
read and understand that the [City Engineer] has adopted minimum requirements for managing urban runoff, including storm water, from land development activities , as described in the BMP Design Manual. I certify that this PDP SWQMP has been completed to the best of my ability and accurately reflects the project bei ng proposed and the applicable BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the plan check review of this PDP SWQMP by the [City Engineer] is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of storm water BMPs for this project, of my responsibilities for project design.
________________
_______________________________________
Engineer of Work's Signature
_William Lundstrom______________________________________________________ Print Name
_Lundstrom Engineering & Surveying, Inc.__________________________________________________ Company
_____02/16/2023__________________
_ Date
Enginee
r's Seal:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
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City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]

PDP SWQMP PROJECT OWNER'S CERTIFICATION PAGE
Project Name: Pacific
Permit Application Number:

PROJECT OWNER'S CERTIFICATION
This PDP SWQMP has been prepared for The Las Posas Project Owner LPV, LLC by Lundstrom Engineering & Surveying, Inc. The PDP SWQMP is intended to comply with the PDP requirements of the City of San Marcos BMP Design Manual, which is a design manual for compliance with local City of San Marcos and regional MS4 Permit (California Regional Water Quality Control Board San Diego Region Order No. R9-2015-0100) requirements for storm water management.

The undersigned, while it owns the subject property, is responsible for the implementation of the provisions of this plan. Once the undersigned transfers its interests in the pro perty, its successor -in- interest shall bear the aforementioned responsibility to implement the best management practices (BMPs) described within this plan, including ensuring on-going operation and maintenance of structural BMPs. A signed copy of this document shall be available on the subject property into perpetuity. ________________________________________________________ Project Owner's Signature
________________________________________________________ Print Name
The Las Posas Project Owner LPV, LLC
Company
____________________________
Date
City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
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City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]

SUBMITTAL RECORD
Use this Ta
ble to keep a record of submittals of this PDP SWQMP. Each time the PDP SWQMP is re- submitted, provide the date and status of the project. In column 4 summarize the changes that have been made or indicate if response to plancheck comments is included. When applicable, insert response to plancheck comments behind this page.

Submittal
Number
Date Project Status Summary of Changes
1 11/07/2022
☑Preliminary Design /
Planning/ CEQA
Final Design
Initial Submittal
2 3 Preliminary Design /
Planning/ CEQA
Final Design
4 Preliminary Design /
Planning/ CEQA
Final Design
04/15/2022
☑Preliminary Design /
Planning/ CEQA
Final Design
☑Preliminary Design /
Planning/ CEQA
Final Design
Resubmittal 08/15/2022
Resubmittal
02/16/2023 Resubmittal
City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]

PROJECT VICINITY MAP

Project Name: Pacific
Permit Application Number:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Applicability of Storm Water Best Management Practices (BMP) Requirements (Storm Water Intake Form for all Development Permit Applications) For detailed information please visit:
http://www.san-marcos.net/departments/development-services/stormwater/development-planning Form I-1
[March 15, 2016]
Project Identification
Project Name: Pacific
The 33.2-acre project site is an infill site located in the western portion of the City of San Marcos (City), at the northwest corner of S. Las Posas Road and Linda Vista Drive, comprised of Assessor’s Parcel Numbers 219-222-01, 219-222-02, 219-222-03, and 219-222-04. La Mirada Drive abuts the site’s northern boundary, while South Pacific Street abuts the property’s western boundary. The Grand Plaza shopping center is located directly across Las Posas Road to the east. Light industrial uses are adjacent to the site’s northern, southern, and western boundary, and Bradley Park is located across from the site’s southwestern corner. Single- and multi-family residential uses are located to the west and south of Bradley Park.

The project consists of 449 residential units, including a mix of apartments, rowhomes, villas, and affordable flats on approximately 15.09 acres of the 33.2-acre project site. Proposed residential units would include a mix of apartments within a five-story podium building, three-story rowhomes, three-story villas, and affordable flats within a four-story building. The project includes a total of 927 parking spaces and 134,985 square feet of common open space area. 68 of the 449 total units (15% of the total) would be designated as deed-restricted affordable units (alternatively, the project reserves the option to contribute to the affordable housing fund by paying the in-lieu fee). The proposed project also includes landscaping, bio- retention areas, and circulation improvements. The remaining 18.11 acres of the 33.2-acre project site would be preserved and restored as open space and habitat area. The proposed project would have a density of approximately 13.5 dwelling units per acre, including the open space and habitat area.

Permit Application Number (if applicable): Date:

Project Address:

Determination of Requirements
This form is required as part of the City’s application process. The purpose of this form is to identify potential land development planning storm water requirements that apply to development projects.

De
velopment projects are defined as construction, rehabilitation, redevelopment, or reconstruction of any public or private projects. In addition, the identification of a development project, as it relates to storm water regulations, would truly apply to development and redevelopment activities that have the potential to contact storm water and contribute a source of pollutants, or reduce the natural absorption and infiltration abilities of the land.

To
access the BMP Design Manual, Storm Water Quality Management Plan (SWQMP) templates, and other pertinent information related to this program please refer to:
http://www.san-marcos.net/departments/development-services/stormwater/development-planning Please answer each of the following steps below, starting with Step 1 and progressing through each step until reaching "Stop".

Step Answer Progression
Step 1: Based on the above, Is the project a
"development project" (See definition above)?
See Section 1.3 of the BMP Design Manual for
further guidance if necessary.
☑Yes Go to Step 2.
No Permanent BMP requirements do not apply. No
SWQMP will be required. Provide brief discussion
below. STOP.

Discussion / justification if the project is not a "development project" (e.g., the project includes only interior remodels within an existing building):

Step 2: Is the project a Standard Project, Priority
Development Project (PDP), or exception to PDP
definitions?
Standard Project Only Standard Project requirements apply, including Standard Project SWQMP. STOP.
☑PDP Standard and PDP requirements apply, including
PDP SWQMP. Go to Step 3 on the following page.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
To answer this item, complete Form I-2, Project
Type Determination. See Section 1.4 of the BMP
Design Manual in its entirety for guidance.

In addition to Section 1.4, please refer to the
City’s SWQMP Submittal Requirements form.

Exception to PDP
definitions
Standard Project requirements apply, and any
additional requirements specific to the type of
project. Provide discussion and list any additional
requirements below. Prepare Standard Project
SWQMP. STOP.

Discussion / justification, and additional requirements for exceptions to PDP definitions, if applicable:

Form I-1 Page 2, Form Date: March 15, 2016
Step 3 (PDPs only). Please answer the list of questions in this section to determine if hydromodification requirements reply to the proposed PDP. Does the project:

Step 3a. Discharge storm water
runoff directly to the Pacific Ocean?
Yes STOP. Hydromodification requirements do not apply. ☑No Continue to Step 3b.

Step 3b. Discharge storm water
runoff directly to an enclosed
embayment, not within protected
areas?
Yes STOP. Hydromodification requirements do not apply. ☑No Continue to Step 3c.

Step 3c. Discharge storm water
runoff directly to a water storage
reservoir or lake, below spillway or
normal operating level?
Yes STOP. Hydromodification requirements do not apply. ☑No Continue to Step 3d.

Step 3d. Discharge storm water
runoff directly to an area identified in
WMAA?
Yes STOP. Hydromodification requirements do not apply. ☑No Hydromodification requirements apply to the project. Go to Step

4. Discussion / justification if hydromodification control requirements do not apply:

Step 4 (PDPs subject to
hydromodification control
requirements only). Does protection
of critical coarse sediment yield areas
apply based on review of WMAA
Potential Critical Coarse Sediment
Yield Area Map?
See Section 6.2 of the BMP Design
Manual for guidance.

Yes Management measures required for protection of critical coarse sediment yield areas (Chapter 6.2).

Stop.
☑No Management measures not required for protection of critical coarse sediment yield areas.

Provide brief discussion below.

Stop.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Project Type Determination Checklist Form I-2
[March 15, 2016]
Project Information
Project Name/Description: Pacific
Permit Application Number (if applicable): Date:

Project Address:

Project Type Determination: Standard Project or Priority Development Project (PDP) The project is (select one): ☑New Development Redevelopment The total proposed newly created or replaced impervious area is: ________ ft 2 (11.5) acres Is the project in any of the following categories, (a) through (f)? Yes
☑
No

(a) New development projects that create 10,000 square feet or more of impervious surfaces (collectively over the entire project site). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

Yes

No
☑
(b) Redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site on an existing site of 10,000 square feet or more of impervious surfaces). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

Yes

No
☑
(c) New and redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site), and support one or more of the following uses:
(i) Restaurants. This category is defined as a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification (SIC) code 5812). (ii) Hillside development projects. This category includes development on any natural slope that is twenty-five percent or greater.
(iii) Parking lots. This category is defined as a land area or facility for the temporary parking or storage of motor vehicles used personally, for business, or for commerce.
(iv) Streets, roads, highways, freeways, and driveways. This category is defined as any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-2 Page 2, Form Date: March 15, 2016
Yes

No
☑
(d) New or redevelopment projects that create and/or replace 2,500 square feet or more of impervious surface (collectively over the entire project site), and discharging directly to an Environmentally Sensitive Area (ESA). “Discharging directly to” includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).

Note: ESAs are areas that include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Board and San Diego Water Board; State Water Quality Protected Areas; water bodies designated with the RARE beneficial use by the State Water Board and San Diego Water Board; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. See BMP Design Manual Section 1.4.2 for additional guidance.

Yes

No
☑
(e) New development projects, or redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface, that support one or more of the following uses:
(i) Automotive repair shops. This category is defined as a facility that is categorized in any one of the following SIC codes: 5013, 5014, 5541, 7532- 7534, or 7536-7539.
(ii) Retail gasoline outlets (RGOs). This category includes RGOs that meet the following criteria: (a) 5,000 square feet or more or (b) a projected Average Daily Traffic (ADT) of 100 or more vehicles per day.

Yes
☑
No

(f) New or redevelopment projects that result in the disturbance of one or more acres of land and are expected to generate pollutants post construction.

Note: See BMP Design Manual Section 1.4.2 for additional guidance.

Does the project meet the definition of one or more of the Priority Development Project categories (a) through (f) listed above?
No – the project is not a Priority Development Project (Standard Project). ☑ Yes – the project is a Priority Development Project (PDP).

The following is for redevelopment PDPs only:

The area of existing (pre-project) impervious area at the project site is: ________ ft2 (A) The total proposed newly created or replaced impervious area is ________ ft2 (B) Percent impervious surface created or replaced (B/A)*100: _______% The percent impervious surface created or replaced is (select one based on the above calculation):
less than or equal to fifty percent (50%) – only new impervious areas are considered PDP OR
greater than fifty percent (50%) – the entire project site is a PDP

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Site Information Checklist
For PDPs
Form I-3B (PDPs)
[March 15, 2016]
Project Summary Information
Project Name Pacific
Project Address
Northwest corner of the intersection of Las Posas
Road and Linda Vista Drive.

Assessor's Parcel Number(s) (APN(s)) 219-222-01, 219-222-02, 219-222-03, 219-222-04 Permit Application Number
Project Hydrologic Unit Select One:
Santa Margarita 902
San Luis Rey 903
☑ Carlsbad 904
San Dieguito 905
Penasquitos 906
San Diego 907
Pueblo San Diego 908
Sweetwater 909
Otay 910
Tijuana 911
Project Watershed
(Complete Hydrologic Unit, Area, and Subarea
Name with Numeric Identifier)
HU Carlsbad, HA San Marcos, HSA 904.52 Richland
Parcel Area
(total area of Assessor's Parcel(s) associated
with the project)

33.2 Acres (____________ Square Feet)
Area to be Disturbed by the Project
(Project Area) 15.2 Acres (____________ Square Feet)
Project Proposed Impervious Area
(subset of Project Area) 11.5 Acres (____________ Square Feet) Project Proposed Pervious Area
(subset of Project Area) 3.7 Acres (____________ Square Feet) Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the Project.

This may be less than the Parcel Area.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 2 of 10, Form Date: March 15, 2016
Description of Existing Site Condition
Current Status of the Site (select all that apply):
Existing development
Previously graded but not built out
Demolition completed without new construction
Agricultural or other non-impervious use
☑Vacant, undeveloped/natural

Description / Additional Information:

The 33.2 acre property is currently undeveloped. Adjacent land use is varied with shopping centers, light industrial, and recreation.

The majority of the site flows southeasterly toward the northwest corner of Linda Vista Drive and Las Posas Road. This drainage is collected in a CMP (corrugated meatal pipe) riser which drains to an 11’x7’ RCB (reinforced concrete box) in Las Posas Rd. The remainder of the site surface drains to the surrounding streets. All surrounding streets drain via gutter flow to the same corner (Las Posas and Linda Vista) where runoff is collected by a pair of curb inlets which drain into the same 11’x7’ RCB in Las Posas Rd. It is noted that some on-site run-off occurs from the property onto adjacent streets. Tha run- off is carried via the streets to the same RCB in Las Posas Road. There is no offsite run-on to the property.

Existing Land Cover Includes (select all that apply):
☑ Vegetative Cover
Non-Vegetated Pervious Areas
Impervious Areas

Description / Additional Information:

Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
NRCS Type A
NRCS Type B
NRCS Type C
☑NRCS Type D

Approximate Depth to Groundwater (GW):
GW Depth < 5 feet
5 feet < GW Depth < 10 feet
10 feet < GW Depth < 20 feet
☑ GW Depth > 20 feet

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Existing Natural Hydrologic Features (select all that apply):
Watercourses
Seeps
Springs
Wetlands
☑ None

Description / Additional Information:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 3 of 10, Form Date: March 15, 2016
Description of Existing Site Drainage Patterns
How is storm water runoff conveyed from the site? At a minimum, this description should answer:
(1) whether existing drainage conveyance is natural or urban; (2) I
s runoff from offsite conveyed through the site? if yes, quantify all offsite drainage areas, design flows, and locations where offsite flows enter the project site, and summarize how such flows are conveyed through the site;
(3)Provide details regarding existing project site drainage conveyance network, including any existing storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels; and
(4
) I
dentify all discharge locations from the existing project site along with a summary of conveyance system size and capacity for each of the discharge locations. Provide summary of the pre-project drainage areas and design flows to each of the existing runoff discharge locations.

Describe existing site drainage patterns:

The majority of the site is natural overland and flows southeasterly toward the northwest corner of Linda Vista Drive and Las Posas Road. This drainage is collected in a CMP (corrugated meatal pipe) riser which drains to an 11’x7’ RCB (reinforced concrete box) in Las Posas Rd. The remainder of the site surface drains to the surrounding streets. All surrounding streets drain via gutter flow to the same corner (Las Posas and Linda Vista) where runoff is collected by a pair of curb inlets which drain into the same 11’x7’ RCB in Las Posas Rd. It is noted that some on-site run-off occurs from the property onto adjacent streets. Tha run-off is carried via the streets to the same RCB in Las Posas Road. There is no offsite run-on to the property.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 4 of 10, Form Date: March 15, 2016
Description of Proposed Site Development
Project Description / Proposed Land Use and/or Activities:

The 33.2-acre project site is an infill site located in the western portion of the City of San Marcos (City), at the northwest corner of S. Las Posas Road and Linda Vista Drive, comprised of Assessor’s Parcel Numbers 219-222-01, 219-222-02, 219-222-03, and 219-222-04. La Mirada Drive abuts the site’s northern boundary, while South Pacific Street abuts the property’s western boundary. The Grand Plaza shopping center is located directly across Las Posas Road to the east. Light industrial uses are adjacent to the site’s northern, southern, and western boundary, and Bradley Park is located across from the site’s southwestern corner. Single- and multi-family residential uses are located to the west and south of Bradley Park.

The project consists of 449 residential units, including a mix of apartments, rowhomes, villas, and affordable flats on approximately 15.09 acres of the 33.2-acre project site. Proposed residential units would include a mix of apartments within a five-story podium building, three-story rowhomes, three-story villas, and affordable flats within a four-story building. The project includes a total of 927 parking spaces and 134,985 square feet of common open space area. 68 of the 449 total units (15% of the total) would be designated as deed-restricted affordable units (alternatively, the project reserves the option to contribute to the affordable housing fund by paying the in-lieu fee). The proposed project also includes landscaping, bio-retention areas, and circulation improvements. The remaining 17.94 acres of the 33.2-acre project site would be preserved and restored as open space and habitat area. The proposed project would have a density of approximately 13.5 dwelling units per acre, including the open space and habitat area.

List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features):

The proposed site will consist of approximately 10.2 acres of impervious area in the form of a p
aved roads, paved driveways, paved walkways and roof areas.

List/describe proposed pervious features of the project (e.g., landscape areas):

The proposed site will consist of approximately 2.9 acres of pervious area in the form of landscaped yards
and common use areas.

Does the project include grading and changes to site topography? ☑Yes
No
Descript
ion / Additional Information: See Attachment 1a.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 5 of 10, Form Date: March 15, 2016
Description of Proposed Site Drainage Patterns
Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)?
☑Yes
No
If yes, provide details regarding the proposed project site drainage conveyance network, including storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels, and the method for conveying offsite flows through or around the proposed project site. Identify all discharge locations from the proposed project site along with a summary of the conveyance system size and capacity for each of the discharge locations. Provide a summary of pre- and post-project drainage areas and design flows to each of the runoff discharge locations. Reference the drainage study for detailed calculations.

Describe proposed site drainage patterns::

The proposed storm drain system will collect and convey stormwater runoff to biofiltration basins and underground hydromodification storage vaults. The proposed storm drain system will convey stormwater southeast to an existing public drainage system in Las Posas Road.

Form I-3B Page 6 of 10, Form Date: March 15, 2016
City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Identify whether any of the following features, activities, and/or pollutant source areas will be present (select all that apply):
☑On-site storm drain inlets
Interior floor drains and elevator shaft sump pumps
☑Interior parking garages
☑Need for future indoor & structural pest control
☑Landscape/Outdoor Pesticide Use
☑Pools, spas, ponds, decorative fountains, and other water features Food service
☑Refuse areas
Industrial processes
Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
Fuel Dispensing Areas
Loading Docks
☑Fire Sprinkler Test Water
Miscellaneous Drain or Wash Water
☑Plazas, sidewalks, and parking lots

Description / Additional Information:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 7 of 10, Form Date: March 15, 2016
Identification and Narrative of Receiving Water and Pollutants of Concern Describe flow path of storm water from the project site discharge location(s), through urban storm conveyance systems as applicable, to receiving creeks, rivers, and lagoons as applicable, and ultimate discharge to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable):

The
existing public drainage system in Las Posas Road conveys stormwater approximately 700 feet downstream to San Marcos Creek and then into Lake San Marcos.

List any 303(d) impaired water bodies within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing impairment, and identify any TMDLs and/or Highest Priority Pollutants from the WQIP for the impaired water bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s)
TMDLs / WQIP Highest Priority
Pollutant
San Marcos Creek DDE, Toxicity, Benthic
Community Effects, Indicator
Bacteria, Phosphorus, and
Selenium
nutrients, bacteria
San Marcos Lake Ammonia as Nitrogen, Copper,
Nutrients, and Phosphorus
Identification of Project Site Pollutants*
*Identification of project site pollutants is only required if flow-thru treatment BMPs are implemented onsite in lieu of retention or biofiltration BMPs (note the project must also participate in an alternative compliance program unless prior lawful approval to meet earlier PDP requirements is demonstrated)
Identify pollutants expected from the project site based on all proposed use(s) of the site (see BMP Design Manual Appendix B.6):

Pollutant
Not Applicable to the
Project Site
Expected from the
Project Site
Also a Receiving Water
Pollutant of Concern
Sediment
Nutrients
Heavy Metals
Organic Compounds
Trash & Debris
Oxygen Demanding
Substances
Oil & Grease
Bacteria & Viruses
Pesticides
XSediment Sediment
X
X
X
X
X
X
X
X
X
X
X
heavy metals, nutrients
City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 8 of 10, Form Date: March 15, 2016
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual)? ☑Yes, hydromodification management flow control structural BMPs required. No, the project will discharge runoff directly to existing underground storm drains discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean. No, the project will discharge runoff directly to conveyance channels whose bed and bank are concrete-lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
No, the project will discharge runoff directly to an area identified as appropriate for an exemption by the WMAA for the watershed in which the project resides.

Description / Additional Information (to be provided if a 'No' answer has been selected above):

Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas exist within the project drainage boundaries?
Yes
☑No, No critical coarse sediment yield areas to be protected based on WMAA maps

If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual been performed?
6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite 6.2.2 Downstream Systems Sensitivity to Coarse Sediment 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite No optional analyses performed, the project will avoid critical coarse sediment yield areas identified based on WMAA maps

If optional analyses were performed, what is the final result? No critical coarse sediment yield areas to be protected based on verification of GLUs onsite Critical coarse sediment yield areas exist but additional analysis has determined that protection is not required. Documentation attached in Attachment 2.b of the SWQMP. Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas are identified on the SWQMP Exhibit.

Discussion / Additional Information:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 9 of 10, Form Date: March 15, 2016
Flow Control for Post-Project Runoff*
*This Section only required if hydromodification management requirements apply List and describe point(s) of compliance (POCs) for flow control for hydromodification management (see Section 6.3.1). For each POC, provide a POC identification name or number correlating to the project's HMP Exhibit and a receiving channel identification name or number correlating to the project's HMP Exhibit.

POC#1: Existing storm drain in Las Posas Road. See Attachment 2a.

Has a geomorphic assessment been performed for the receiving channel(s)? ☑No, the low flow threshold is 0.1Q2 (default low flow threshold) Yes, the result is the low flow threshold is 0.1Q2
Yes, the result is the low flow threshold is 0.3Q2
Yes, the result is the low flow threshold is 0.5Q2

If a geomorphic assessment has been performed, provide title, date, and preparer:

Discussion / Additional Information: (optional)

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-3B Page 10 of 10, Form Date: March 15, 2016
Other Site Requirements and Constraints
When applicable, list other site requirements or constraints that will influence storm water management design, such as zoning requirements including setbacks and open space, or local codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements.

The project is constrained by 17.8 acres of open space (self-mitigating).

Proposed frontage improvements will have biofiltration BMPs and tree wells for stormwater treatment.

Optional Additional Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Source Control BMP Checklist
for All Development Projects
(Standard Projects and Priority Development Projects)
Form I-4
[March 15, 2016]
Project Identification
Project Name
Permit Application Number
Source Control BMPs
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See Chapter 4 and Appendix E of the Model BMP Design Manual for information to implement source control BMPs shown in this checklist.

Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E of the Model BMP Design Manual. Discussion / justification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project has no outdoor materials storage areas).

Discussion / justification may be provided.

Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4 ☑Yes No N/A Discussion / justification if SC-1 not implemented:

SC-2 Storm Drain Stenciling or Signage ☑Yes No N/A
Discussion / justification if SC-2 not implemented:

SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
Yes No ☑N/A
Discussion / justification if SC-3 not implemented:

SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
Yes No ☑N/A
Discussion / justification if SC-4 not implemented:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-4 Page 2 of 2, Form Date: March 15, 2016
Source Control Requirement Applied?
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
☑Yes No N/A
Discussion / justification if SC-5 not implemented:

SC-6 Additional BMPs Based on Potential Sources of Runoff Pollutants (must answer for each source listed below)
☑On-site storm drain inlets
☑Interior floor drains and elevator shaft sump pumps
☑Interior parking garages
☑Need for future indoor & structural pest control
☑Landscape/Outdoor Pesticide Use
☑Pools, spas, ponds, decorative fountains, and other water features Food service
Refuse areas
Industrial processes
Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
Fuel Dispensing Areas
Loading Docks
☑Fire Sprinkler Test Water
Miscellaneous Drain or Wash Water
☑Plazas, sidewalks, and parking lots

Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

N/A
N/A
N/A
N/A
N/A
N/A
☑N/A
☑N/A
☑N/A
☑N/A
☑N/A
☑N/A
☑N/A
☑N/A
☐N/A
N/A
N/A
Discussion / justification if SC-6 not implemented. Clearly identify which sources of runoff pollutants are discussed. Justification must be provided for all "No" answers shown above.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Site Design BMP Checklist
for All Development Projects
(Standard Projects and Priority Development Projects)
Form I-5
[March 15, 2016]
Project Identification
Project Name
Permit Application Number
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See Chapter 4 and Appendix E of the Model BMP Design Manual for information to implement site design BMPs shown in this checklist.

Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMP as described in Chapter 4 and/or Appendix E of the Model BMP Design Manual. Discussion / justification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project site has no existing natural areas to conserve).

Discussion / justification may be provided.

Site Design Requirement Applied?
SD-1 Maintain Natural Drainage Pathways and Hydrologic Features Yes No ☑N/A Discussion / justification if SD-1 not implemented:

SD-2 Conserve Natural Areas, Soils, and Vegetation ☑Yes No N/A Discussion / justification if SD-2 not implemented:

SD-3 Minimize Impervious Area ☑Yes No N/A
Discussion / justification if SD-3 not implemented:

SD-4 Minimize Soil Compaction ☑Yes No N/A
Discussion / justification if SD-4 not implemented:

SD-5 Impervious Area Dispersion Yes ☑No N/A
Discussion / justification if SD-5 not implemented:

Project runoff will be routed to tree wells and biofiltration basins.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-5 Page 2 of 2, Form Date: March 15, 2016
Site Design Requirement Applied?
SD-6 Runoff Collection ☑Yes No N/A
Discussion / justification if SD-6 not implemented:

Harvest and Reuse is not feasible for the
project. Collecting runoff through permeable pavement is not feasible due to low infiltration rates.

SD-7 Landscaping with Native or Drought Tolerant Species ☑Yes No N/A Discussion / justification if SD-7 not implemented:

SD-8 Harvesting and Using Precipitation Yes No ☑N/A Discussion / justification if SD-8 not implemented:

Harvest and Reuse is not feasible for the
project.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Summary of PDP Structural BMPs Form I-6 (PDPs)
[March 15, 2016]
Project Identification
Project Name: Pacific
Permit Application Number
PDP Structural BMPs
All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control must be based on the selection process described in Chapter 5. PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both storm water pollutant control and flow control for hydromodification management can be achieved within the same structural BMP(s).

PDP
structural BMPs must be verified by the local jurisdiction at the completion of construction. This may include requiring the project owner or project owner's representative and engineer of record to certify construction of the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must be maintained into perpetuity, and the local jurisdiction must confirm the maintenance (see Section 7 of the BMP Design Manual).

Use this form to provide narrative description of the general strategy for structural BMP implementation at the project site in the box below. Then complete the PDP structural BMP summary information sheet (page 3 of this form) for each structural BMP within the project (copy the BMP summary information page as many times as needed to provide summary information for each individual structural BMP).

Describe the general strategy for structural BMP implementation at the site. This information must describe how the steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of BMPs selected).

For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated or separate.

Infiltration is not feasible per the attached soils report.

The project proposed biofiltration basins and tree wells with nutrient sensitive media for site design treatment BMP and modular underground detention systems for HMP for control and 100 year detention.

The project is constrained by 17.8 acres of open space (self-mitigating).Proposed frontage improvements will have biofiltration BMPs and tree wells for stormwater treatment. (Continue on page 2 as necessary.)
City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Form I-6 Page 2 of X, Form Date: March 15, 2016
(Page reserved for continuation of description of general strategy for structural BMP implementation at the site)
(Continued from page 1)

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
ATTACHMENT 1

BACKUP FOR PDP POLLUTANT CONTROL BMPS

This is the cover sheet for Attachment 1.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 1a DMA Exhibit (Required)

See DMA Exhibit Checklist on the back of
this Attachment cover sheet.

Harvest and Reuse is not feasible for
the
project. Included

Attachment 1b Tabular Summary of DMAs Showing
DMA ID matching DMA Exhibit, DMA
Area, and DMA Type (Required)*

*Provide table in this Attachment OR on
DMA Exhibit in Attachment 1a

☑Included on DMA Exhibit in
Attachment 1a
Included as Attachment 1b, separate
from DMA Exhibit

Attachment 1c Form I -7, Harvest and Use Feasibility
Screening Checklist (Required unless the
entire project will use infiltration BMPs)

Refer to Appendix B.3 -1 of the BMP
Design Manual to complete Form I-7.

☑Included
Not included because the entire
project will use infiltration BMPs

Attachment 1d Form I -8, Categorization of Infiltration Feasibility Condition (Required unless
the project will use harvest and use
BMPs)

Refer to Appendices C and D of the BMP
Design Manual to complete Form I-8.

☑Included
Not included because the entire
project will use harvest and use
BMPs

Attachment 1e Pollutant Control BMP Design
Worksheets / Calculations (Required)

Refer to Appendices B and E of the BMP
Design Manual for structural pollutant
control BMP design guidelines

☑Included

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Use this checklist to ensure the required information has been included on the DMA Exhibit:

The DMA Exhibit must identify:

Underlying hydrologic soil group
Approximate depth to groundwater
Existing natural hydrologic features ( watercourses, seeps, springs, wetlands) Critical coarse sediment yield areas to be protected
Existing topography and impervious areas
Existing and proposed site drainage network and connections to drainage offsite Proposed demolition
Proposed grading
Proposed impervious features
Proposed design features and surface treatments used to minimize imperviousness Drainage management area (DMA) boundaries, DMA ID numbers, and DMA areas (square footage or acreage), and DMA type (i.e., drains to BMP, self-retaining, or self-mitigating) Potential pollutant source areas and corresponding required source controls (see Chapter 4, Appendix E.1, and Form I-3B)
Structural BMPs (identify location, type of BMP, and size/detail)

Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name DMA 1A DMA 1B DMA 2 DMA 3A DMA 3B DMA 3C DMA 3D DMA 4 DMA 5 DMA 7 unitless 2 85th Percentile 24-hr Storm Depth 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 inches 3 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 19,800 125,875 190,940 12,930 16,500 15,600 80,534 40,000 51,250 57,200 sq-ft 4 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30) sq-ft 5 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10) 4,900 41,960 56,400 6,370 8,100 7,600 39,666 38,600 sq-ft 6 Natural Type A Soil Not Serving as Dispersion Area (C=0.10) sq-ft 7 Natural Type B Soil Not Serving as Dispersion Area (C=0.14) sq-ft 8 Natural Type C Soil Not Serving as Dispersion Area (C=0.23) sq-ft 9 Natural Type D Soil Not Serving as Dispersion Area (C=0.30) sq-ft 10 Does Tributary Incorporate Dispersion, Tree Wells, and/or Rain Barrels? Yes Yes Yes No No No Yes No No No yes/no 11 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) sq-ft 12 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30) sq-ft 13 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10) sq-ft 14 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10) sq-ft 15 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14) sq-ft 16 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23) sq-ft 17 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30) sq-ft 18 Number of Tree Wells Proposed per SD-A 5 15 6 #
19 Average Mature Tree Canopy Diameter 20 20 20 ft
20 Number of Rain Barrels Proposed per SD-E #
21 Average Rain Barrel Size gal
22 Total Tributary Area 24,700 167,835 247,340 19,300 24,600 23,200 120,200 78,600 51,250 57,200 sq-ft 23 Initial Runoff Factor for Standard Drainage Areas 0.74 0.70 0.72 0.64 0.64 0.64 0.64 0.51 0.90 0.90 unitless 24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 25 Initial Weighted Runoff Factor 0.74 0.70 0.72 0.64 0.64 0.64 0.64 0.51 0.90 0.90 unitless 26 Initial Design Capture Volume 1,142 7,343 11,130 772 984 928 4,808 2,505 2,883 3,218 cubic-feet 27 Total Impervious Area Dispersed to Pervious Surface 0 0 0 0 0 0 0 0 0 0 sq-ft 28 Total Pervious Dispersion Area 0 0 0 0 0 0 0 0 0 0 sq-ft 29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a ratio 30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 ratio 31 Runoff Factor After Dispersion Techniques 0.74 0.70 0.72 0.64 0.64 0.64 0.64 0.51 0.90 0.90 unitless 32 Design Capture Volume After Dispersion Techniques 1,142 7,343 11,130 772 984 928 4,808 2,505 2,883 3,218 cubic-feet 33 Total Tree Well Volume Reduction 0 900 2,700 0 0 0 1,080 0 0 0 cubic-feet 34 Total Rain Barrel Volume Reduction 0 0 0 0 0 0 0 0 0 0 cubic-feet 35 Final Adjusted Runoff Factor 0.74 0.61 0.55 0.64 0.64 0.64 0.50 0.51 0.90 0.90 unitless 36 Final Effective Tributary Area 18,278 102,379 136,037 12,352 15,744 14,848 60,100 40,086 46,125 51,480 sq-ft 37 Initial Design Capture Volume Retained by Site Design Elements 0 900 2,700 0 0 0 1,080 0 0 0 cubic-feet 38 Final Design Capture Volume Tributary to BMP 1,142 6,443 8,430 772 984 928 3,728 2,505 2,883 3,218 cubic-feet False
False
Automated Worksheet B.1: Calculation of Design Capture Volume (V2.0) Dispersion
Area, Tree Well
& Rain Barrel
Inputs
(Optional)
Standard
Drainage Basin
Inputs
Results
Tree & Barrel
Adjustments
Initial Runoff
Factor
Calculation
Dispersion
Area
Adjustments
No Warning Messages
Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name DMA 1A DMA 1B DMA 2 DMA 3A DMA 3B DMA 3C DMA 3D DMA 4 DMA 5 DMA 7 unitless 2 85th Percentile Rainfall Depth 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 inches 3 Predominant NRCS Soil Type Within BMP Location D D D D D D D D D D unitless 4 Is proposed BMP location Restricted or Unrestricted for Infiltration Activities? Restricted Restricted Restricted Restricted Restricted Restricted Restricted Restricted Restricted Restricted unitless 5 Nature of Restriction Soil Type Soil Type Soil Type Soil Type Soil Type Soil Type Soil Type Soil Type Soil Type Soil Type unitless 6 Do Minimum Retention Requirements Apply to this Project? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes yes/no 7 Are Habitable Structures Greater than 9 Stories Proposed? No No No No No No No No No No yes/no 8 Has Geotechnical Engineer Performed an Infiltration Analysis? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes yes/no 9 Design Infiltration Rate Recommended by Geotechnical Engineer 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 in/hr 10 Design Infiltration Rate Used To Determine Retention Requirements 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 in/hr 11 Percent of Average Annual Runoff that Must be Retained within DMA 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% percentage 12 Fraction of DCV Requiring Retention 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 ratio 13 Required Retention Volume 11 64 84 8 10 9 37 25 29 32 cubic-feet False
False
Automated Worksheet B.2: Retention Requirements (V2.0)
Advanced
Analysis
Basic Analysis
Result
No Warning Messages
Category # Description i ii iii iv v vi vii viii ix x Units 1 Drainage Basin ID or Name DMA 1A DMA 1B DMA 2 DMA 3A DMA 3B DMA 3C DMA 3D DMA 4 DMA 5 DMA 7 sq-ft 2 Design Infiltration Rate Recommended 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 in/hr 3 Design Capture Volume Tributary to BMP 1,142 3,068 8,430 772 984 928 3,728 2,505 2,883 3,218 cubic-feet 4 Is BMP Vegetated or Unvegetated? Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated unitless 5 Is BMP Impermeably Lined or Unlined? Lined Lined Lined Lined Lined Lined Lined Lined Lined Lined unitless 6 Does BMP Have an Underdrain? Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain unitless 7 Does BMP Utilize Standard or Specialized Media? Standard Standard Specialized Standard Standard Standard Specialized Standard Standard Standard unitless 8 Provided Surface Area 700 1,470 400 400 500 500 180 2,400 3,700 1,600 sq-ft 9 Provided Surface Ponding Depth 6 6 6 6 6 6 6 6 6 6 inches 10 Provided Soil Media Thickness 18 18 18 18 18 18 18 18 18 18 inches 11 Provided Gravel Thickness (Total Thickness) 18 18 18 12 18 18 18 18 18 18 inches 12 Underdrain Offset 3 3 3 3 3 3 3 3 3 3 inches
13 Diameter of Underdrain or Hydromod Orifice (Select Smallest) 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 8.00 inches 14 Specialized Soil Media Filtration Rate 175.00 175.00 in/hr 15 Specialized Soil Media Pore Space for Retention 0.20 0.20 unitless 16 Specialized Soil Media Pore Space for Biofiltration 0.20 0.20 unitless 17 Specialized Gravel Media Pore Space 0.40 0.40 unitless 18 Volume Infiltrated Over 6 Hour Storm 0 0 0 0 0 0 0 0 0 0 cubic-feet 19 Ponding Pore Space Available for Retention 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 20 Soil Media Pore Space Available for Retention 0.05 0.05 0.20 0.05 0.05 0.05 0.20 0.05 0.05 0.05 unitless 21 Gravel Pore Space Available for Retention (Above Underdrain) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless 22 Gravel Pore Space Available for Retention (Below Underdrain) 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless 23 Effective Retention Depth 2.10 2.10 4.80 2.10 2.10 2.10 4.80 2.10 2.10 2.10 inches 24 Fraction of DCV Retained (Independent of Drawdown Time) 0.11 0.08 0.02 0.09 0.09 0.09 0.02 0.17 0.22 0.09 ratio 25 Calculated Retention Storage Drawdown Time 120 120 120 120 120 120 120 120 120 120 hours 26 Efficacy of Retention Processes 0.13 0.10 0.02 0.11 0.11 0.11 0.02 0.19 0.24 0.11 ratio 27 Volume Retained by BMP (Considering Drawdown Time) 149 296 204 84 107 101 90 478 687 350 cubic-feet 28 Design Capture Volume Remaining for Biofiltration 993 2,772 8,226 688 877 827 3,638 2,027 2,196 2,868 cubic-feet 29 Max Hydromod Flow Rate through Underdrain 2.8704 2.8704 2.8704 2.6128 2.8704 2.8704 2.8704 2.8704 2.8704 2.8704 cfs 30 Max Soil Filtration Rate Allowed by Underdrain Orifice 177.15 84.36 310.01 282.18 248.00 248.00 688.90 51.67 33.51 77.50 in/hr 31 Soil Media Filtration Rate per Specifications 5.00 5.00 175.00 5.00 5.00 5.00 175.00 5.00 5.00 5.00 in/hr 32 Soil Media Filtration Rate to be used for Sizing 5.00 5.00 175.00 5.00 5.00 5.00 175.00 5.00 5.00 5.00 in/hr 33 Depth Biofiltered Over 6 Hour Storm 30.00 30.00 1050.00 30.00 30.00 30.00 1050.00 30.00 30.00 30.00 inches 34 Ponding Pore Space Available for Biofiltration 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 unitless 35 Soil Media Pore Space Available for Biofiltration 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 unitless 36 Gravel Pore Space Available for Biofiltration (Above Underdrain) 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 unitless 37 Effective Depth of Biofiltration Storage 15.60 15.60 15.60 13.20 15.60 15.60 15.60 15.60 15.60 15.60 inches 38 Drawdown Time for Surface Ponding 1 1 0 1 1 1 0 1 1 1 hours 39 Drawdown Time for Effective Biofiltration Depth 3 3 0 3 3 3 0 3 3 3 hours 40 Total Depth Biofiltered 45.60 45.60 1065.60 43.20 45.60 45.60 1065.60 45.60 45.60 45.60 inches 41 Option 1 - Biofilter 1.50 DCV: Target Volume 1,489 4,157 12,339 1,032 1,316 1,241 5,457 3,040 3,295 4,302 cubic-feet 42 Option 1 - Provided Biofiltration Volume 1,489 4,157 12,339 1,032 1,316 1,241 5,457 3,040 3,295 4,302 cubic-feet 43 Option 2 - Store 0.75 DCV: Target Volume 744 2,079 6,170 516 658 620 2,728 1,520 1,647 2,151 cubic-feet 44 Option 2 - Provided Storage Volume 744 1,911 520 440 650 620 234 1,520 1,647 2,080 cubic-feet 45 Portion of Biofiltration Performance Standard Satisfied 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 ratio 46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements? Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes yes/no 47 Overall Portion of Performance Standard Satisfied (BMP Efficacy Factor) 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 ratio 48 Deficit of Effectively Treated Stormwater 0 0 0 0 0 0 0 0 0 0 cubic-feet Retention
Calculations
Automated Worksheet B.3: BMP Performance (V2.0)
False
False
BMP Inputs
Biofiltration
Calculations
False
- BMPs sized at <3% of the effective tributary areas must be accompanied by Reduced Size BMP Maintenance calculations (see last tab).

False
False
Result
False
-Use of specialized or proprietary media requires submittal of supplemental information outlined in Appendix F of the BMPDM.

Attention!
Filterra Infiltration Rate = 175 (in/hr)
Filterra Flow per Square Foot = 0.00405 (ft3/sec/ft2)
Filterra Flow Rate, Q = 0.00405 ft3/sec x Filterra Surface Area Rational Method, Q = C x I x A
San Diego Multiplier, M = 1.5
Site Flowrate, Q = (C x DI x DA x M x 43560) / (12 x3600) OR DA = (12 x 3600 x Q) / (C x 43560 x DI x M)
where Q = Flow (ft3/sec)
DA = Drainage Area (acres)
DI = Design Intensity (in/hr)
C =Runoff coefficient (dimensionless)
M = Multiplier (dimensionless)

DI C C C

0.2 0.95 0.85 0.50
Filterra 100% Commercial Residential
L W Filterra Surface AreaFlow Rate, Q Imperv. DA max DA max DA (ft) (ft) (ft2) (ft3/sec) (acres) (acres) (acres)
4 4 16 0.0648 0.226 0.252 0.429
6 4 24 0.0972 0.338 0.378 0.643

6.5 4 26 0.1053 0.367 0.410 0.696
8 4 32 0.1296 0.451 0.504 0.857
12 4 48 0.1944 0.677 0.756 1.286
6 6 36 0.1458 0.507 0.567 0.964
8 6 48 0.1944 0.677 0.756 1.286
10 6 60 0.2431 0.846 0.945 1.607
12 6 72 0.2917 1.015 1.134 1.928
13 7 91 0.3686 1.283 1.434 2.437
12 8 96 0.3889 1.353 1.512 2.571
14 8 112 0.4537 1.579 1.765 3.000
16 8 128 0.5185 1.804 2.017 3.428
18 8 144 0.5833 2.030 2.269 3.857
20 8 160 0.6481 2.255 2.521 4.285
22 8 176 0.7130 2.481 2.773 4.714
Available Filterra Box Sizes
Filterra Sizing Spreadsheet
Uniform Intensity Approach
Storm Intensity = 0.20 in/hr
San Diego Region
9/20/2019

1 September 2019

GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), ENHANCED,

PHOSPHORUS & OIL TREATMENT

For

CONTECH Engineered Solutions Filterra®

Ecology’s Decision:

Based on Contech’s submissions, including the Final Technical Evaluation Reports, dated August 2019, March 2014, December 2009, and additional information provided to Ecology dated October 9, 2009, Ecology hereby issues the following use level designations:

1. A General Use Level Designation for Basic, Enhanced, Phosphorus, and Oil Treatment for the Filterra® system constructed with a minimum media thickness of 21 inches (1.75 feet), at the following water quality design hydraulic loading rates:

Treatment Infiltration Rate (in/hr) for
use in Sizing
Basic 175
Phosphorus 100
Oil 50
Enhanced 175

2. The Filterra is not appropriate for oil spill-control purposes.

3. Ecology approves Filterra systems for treatment at the hydraulic loading rates listed above, to achieve the maximum water quality design flow rate. Calculate the water quality design flow rates using the following procedures:
 Western Washington: for treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology-approved continuous runoff model.
 Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three flow rate based methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual.  Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility.

2 4. This General Use Level Designation has no expiration date, but Ecology may revoke or amend the designation, and is subject to the conditions specified below.

Ecology’s Conditions of Use:

Filterra systems shall comply with these conditions shall comply with the following conditions:

1. Design, assemble, install, operate, and maintain the Filterra systems in accordance with applicable Contech Filterra manuals and this Ecology Decision.

2. The minimum size filter surface-area for use in Washington is determined by using the design water quality flow rate (as determined in this Ecology Decision, Item 3, above) and the Infiltration Rate from the table above (use the lowest applicable Infiltration Rate depending on the level of treatment required). Calculate the required area by dividing the water quality design flow rate (cu-ft/sec) by the Infiltration Rate (converted to ft/sec) to obtain required surface area (sq-ft) of the Filterra unit.

3. Each site plan must undergo Contech Filterra review before Ecology can approve the unit for site installation. This will ensure that design parameters including site grading and slope are appropriate for use of a Filterra unit.

4. Filterra media shall conform to the specifications submitted to and approved by Ecology and shall be sourced from Contech Engineered Solutions, LLC with no substitutions.

5. Maintenance includes removing trash, degraded mulch, and accumulated debris from the filter surface and replacing the mulch layer. Use inspections to determine the site-specific maintenance schedules and requirements. Follow maintenance procedures given in the most recent version of the Filterra Operation and Maintenance Manual.

6. Maintenance: The required maintenance interval for stormwater treatment devices is often dependent upon the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a “one size fits all” maintenance cycle for a particular model/size of manufactured treatment device.  Contech designs Filterra systems for a target maintenance interval of 6 months in the Pacific Northwest. Maintenance includes removing and replacing the mulch layer above the media along with accumulated sediment, trash, and captured organic materials therein, evaluating plant health, and pruning the plant if deemed necessary.  Conduct maintenance following manufacturer’s guidelines.

7. Filterra systems come in standard sizes.

8. Install the Filterra in such a manner that flows exceeding the maximum Filterra operating rate are conveyed around the Filterra mulch and media and will not resuspend captured sediment.

9. Discharges from the Filterra units shall not cause or contribute to water quality standards violations in receiving waters.

3 Approved Alternate Configurations
Filterra Internal Bypass - Pipe (FTIB-P)

1. The Filterra® Internal Bypass – Pipe allows for piped-in flow from area drains, grated inlets, trench drains, and/or roof drains. Design capture flows and peak flows enter the structure through an internal slotted pipe. Filterra® inverted the slotted pipe to allow design flows to drop through to a series of splash plates that then disperse the design flows over the top surface of the Filterra® planter area. Higher flows continue to bypass the slotted pipe and convey out the structure.

2. To select a FTIB-P unit, the designer must determine the size of the standard unit using the sizing guidance described above.

Filterra Internal Bypass – Curb (FTIB-C)

1. The Filterra® Internal Bypass –Curb model (FTIB-C) incorporates a curb inlet, biofiltration treatment chamber, and internal high flow bypass in one single structure. Filterra® designed the FTIB-C model for use in a “Sag” or “Sump” condition and will accept flows from both directions along a gutter line. An internal flume tray weir component directs treatment flows entering the unit through the curb inlet to the biofiltration treatment chamber. Flows in excess of the water quality treatment flow rise above the flume tray weir and discharge through a standpipe orifice; providing bypass of untreated peak flows. Americast manufactures the FTIB-C model in a variety of sizes and configurations and you may use the unit on a continuous grade when a single structure providing both treatment and high flow bypass is preferred. The FTIB-C model can also incorporate a separate junction box chamber to allow larger diameter discharge pipe connections to the structure.

2. To select a FTIB-C unit, the designer must determine the size of the standard unit using the sizing guidance described above.

Filterra® Shallow

1. The Filterra Shallow provides additional flexibility for design engineers and designers in situations where various elevation constraints prevent application of a standard Filterra configuration. Engineers can design this system up to six inches shallower than any of the previous Filterra unit configurations noted above.

2. Ecology requires that the Filterra Shallow provide a media contact time equivalent to that of the standard unit. This means that with a smaller depth of media, the surface area must increase.

3. To select a Filterra Shallow System unit, the designer must first identify the size of the standard unit using the modeling guidance described above.

4. Once the size of the standard Filterra unit is established using the sizing technique described above, use information from the following table to select the appropriate size Filterra Shallow System unit.

4 Shallow Unit Basic, Enhanced, and Oil Treatment Sizing Standard Depth Equivalent Shallow Depth
4x4 4x6 or 6x4
4x6 or 6x4 6x6
4x8 or 8x4 6x8 or 8x6
6x6 6x10 or 10x6
6x8 or 8x6 6x12 or 12x6
6x10 or 10x6 13x7
Notes:

1. Shallow Depth Boxes are less than the standard depth of 3.5 feet but no less than 3.0 feet deep (TC to INV).

Applicant: Contech Engineered Solutions, LLC.

Applicant’s Address: 11815 NE Glenn Widing Drive
Portland, OR 97220

Application Documents:

 State of Washington Department of Ecology Application for Conditional Use Designation, Americast (September 2006)
 Quality Assurance Project Plan Filterra® Bioretention Filtration System Performance Monitoring, Americast (April 2008)
 Quality Assurance Project Plan Addendum Filterra® Bioretention Filtration System Performance Monitoring, Americast (June 2008)
 Draft Technical Evaluation Report Filterra® Bioretention Filtration System Performance Monitoring, Americast (August 2009)
 Final Technical Evaluation Report Filterra® Bioretention Filtration System Performance Monitoring, Americast (December 2009)
 Technical Evaluation Report Appendices Filterra® Bioretention Filtration System Performance Monitoring, Americast, (August 2009)
 Memorandum to Department of Ecology Dated October 9, 2009 from Americast, Inc. and Herrera Environmental Consultants
 Quality Assurance Project Plan Filterra® Bioretention System Phosphorus treatment and Supplemental Basic and Enhanced Treatment Performance Monitoring, Americast (November 2011)
 Filterra® letter August 24, 2012 regarding sizing for the Filterra® Shallow System.  University of Virginia Engineering Department Memo by Joanna Crowe Curran, Ph. D dated March 16, 2013 concerning capacity analysis of Filterra® internal weir inlet tray.  Terraphase Engineering letter to Jodi Mills, P.E. dated April 2, 2013 regarding Terraflume Hydraulic Test, Filterra® Bioretention System and attachments.  Technical Evaluation Report, Filterra® System Phosphorus Treatment and Supplemental Basic Treatment Performance Monitoring. March 27th, 2014.  State of Washington Department of Ecology Application for Conditional Use Level Designation, Contech Engineered Solutions (May 2015)

5  Quality Assurance Project Plan Filterra® Bioretention System, Contech Engineered Solutions (May 2015)
 Filterra Bioretention System Armco Avenue General Use Level Designation Technical Evaluation Report, Contech Engineered Solutions (August 2019)

Applicant’s Use Level Request:

General Level Use Designation for Basic (175 in/hr), Enhanced (175 in/hr), Phosphorus (100 in/hr), and Oil Treatment (50 in/hr).

Applicant’s Performance Claims:

Field-testing and laboratory testing show that the Filterra® unit is promising as a stormwater treatment best management practice and can meet Ecology’s performance goals for basic, enhanced, phosphorus, and oil treatment.

Findings of Fact:

Field Testing 2015-2019

1. Contech completed field testing of a 4 ft. x 4 ft. Filterra® unit at one site in Hillsboro, Oregon from September 2015 to July 2019. Throughout the monitoring period a total of 24 individual storm events were sampled, of which 23 qualified for TAPE sampling criteria.

2. Contech encountered several unanticipated events and challenges that prevented them from collecting continuous flow and rainfall data. An analysis of the flow data from the sampled events, including both the qualifying and non-qualifying events, demonstrated the system treated over 99 % of the influent flows. Peak flows during these events ranged from 25 % to 250 % of the design flow rate of 29 gallons per minute.

3. Of the 23 TAPE qualified sample events, 13 met requirements for TSS analysis. Influent concentrations ranged from 20.8 mg/L to 83 mg/L, with a mean concentration of 46.3 mg/L. The UCL95 mean effluent concentration was 15.9 mg/L, meeting the 20 mg/L performance goal for Basic Treatment.

4. All 23 TAPE qualified sample events met requirements for dissolved zinc analysis. Influent concentrations range from 0.0384 mg/L to 0.2680 mg/L, with a mean concentration of

0.0807 mg/L. The LCL 95 mean percent removal was 62.9 %, meeting the 60 % performance goal for Enhanced Treatment.

5. Thirteen of the 23 TAPE qualified sample events met requirements for dissolved copper analysis. Influent concentrations ranged from 0.00543 mg/L to 0.01660 mg/L, with a mean concentration of 0.0103 mg/L. The LCL 95 mean percent removal was 41.2 %, meeting the 30 % performance goal for Enhanced Treatment.

6. Total zinc concentrations were analyzed for all 24 sample events. Influent EMCs for total zinc ranged from 0.048 mg/L to 5.290 mg/L with a median of 0.162 mg/L. Corresponding effluent EMCs for total zinc ranged from 0.015 mg/L to 0.067 mg/L with a median of

6 0.029 mg/L. Total event loadings for the study for total zinc were 316.85 g at the influent and 12.92 g at the effluent sampling location, resulting in a summation of loads removal efficiency of 95.9 %.

7. Total copper concentrations were analyzed for all 24 sample events. Influent EMCs for total copper ranged from 0.003 mg/L to 35.600 mg/L with a median value of 0.043 mg/L.

Corresponding effluent EMCs for total copper ranged from 0.002 mg/L to 0.015 mg/L with a median of 0.004 mg/L. Total event loadings for total copper for the study were 1,810.06 g at the influent and 1.90 g at the effluent sampling location, resulting in a summation of loads removal efficiency of 99.9 %.

Field Testing 2013

1. Filterra completed field-testing of a 6.5 ft x 4 ft. unit at one site in Bellingham, Washington. Continuous flow and rainfall data collected from January 1, 2013 through July 23, 2013 indicated that 59 storm events occurred. Water quality data was obtained from 22 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data.

2. The system treated 98.9 % of the total 8-month runoff volume during the testing period.

Consequently, the system achieved the goal of treating 91 % of the volume from the site.

Stormwater runoff bypassed Filterra treatment during four of the 59 storm events.

3. Of the 22 sampled events, 18 qualified for TSS analysis (influent TSS concentrations ranged from 25 to 138 mg/L). The data were segregated into sample pairs with influent concentration greater than and less than 100 mg/L. The UCL95 mean effluent concentration for the data with influent less than 100 mg/L was 5.2 mg/L, below the 20- mg/L threshold. Although the TAPE guidelines do not require an evaluation of TSS removal efficiency for influent concentrations below 100 mg/L, the mean TSS removal for these samples was 90.1 %. Average removal of influent TSS concentrations greater than 100 mg/L (three events) was 85 %. In addition, the system consistently exhibited TSS removal greater than 80 % at flow rates equivalent to a 100 in/hr infiltration rate and was observed at 150 in/hr.

4. Ten of the 22 sampled events qualified for TP analysis. Americast augmented the dataset using two sample pairs from previous monitoring at the site. Influent TP concentrations ranged from 0.11 to 0.52 mg/L. The mean TP removal for these twelve events was 72.6 %. The LCL95 mean percent removal was 66.0, well above the TAPE requirement of 50 %. Treatment above 50 % was evident at 100 in/hr infiltration rate and as high as 150 in/hr. Consequently, the Filterra test system met the TAPE Phosphorus Treatment goal at 100 in/hr. Influent ortho-P concentrations ranged from 0.005 to 0.012 mg/L; effluent ortho-P concentrations ranged from 0.005 to 0.013 mg/L. The reporting limit/resolution for the ortho-P test method is 0.01 mg/L, therefore the influent and effluent ortho-P concentrations were both at and near non-detect concentrations.

7 Field Testing 2008-2009

1. Filterra completed field-testing at two sites at the Port of Tacoma. Continuous flow and rainfall data collected during the 2008-2009 monitoring period indicated that 89 storm events occurred. The monitoring obtained water quality data from 27 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data.

2. During the testing at the Port of Tacoma, 98.96 to 99.89 % of the annual influent runoff volume passed through the POT1 and POT2 test systems respectively. Stormwater runoff bypassed the POT1 test system during nine storm events and bypassed the POT2 test system during one storm event. Bypass volumes ranged from 0.13 % to 15.3% of the influent storm volume. Both test systems achieved the 91 % water quality treatment-goal over the 1-year monitoring period.

3. Consultants observed infiltration rates as high as 133 in/hr during the various storms.

Filterra did not provide any paired data that identified percent removal of TSS, metals, oil, or phosphorus at an instantaneous observed flow rate.

4. The maximum storm average hydraulic loading rate associated with water quality data is <40 in/hr, with the majority of flow rates < 25 in/hr. The average instantaneous hydraulic loading rate ranged from 8.6 to 53 in/hr.

5. The field data showed a removal rate greater than 80 % for TSS with an influent concentration greater than 20 mg/L at an average instantaneous hydraulic loading rate up to 53 in/hr (average influent concentration of 28.8 mg/L, average effluent concentration of 4.3 mg/L).

6. The field data showed a removal rate generally greater than 54 % for dissolved zinc at an average instantaneous hydraulic loading rate up to 60 in/hr and an average influent concentration of 0.266 mg/L (average effluent concentration of 0.115 mg/L).

7. The field data showed a removal rate generally greater than 40 % for dissolved copper at an average instantaneous hydraulic loading rate up to 35 in/hr and an average influent concentration of 0.0070 mg/L (average effluent concentration of 0.0036 mg/L).

8. The field data showed an average removal rate of 93 % for total petroleum hydrocarbon (TPH) at an average instantaneous hydraulic loading rate up to 53 in/hr and an average influent concentration of 52 mg/L (average effluent concentration of 2.3 mg/L). The data also shows achievement of less than 15 mg/L TPH for grab samples. Filterra provided limited visible sheen data due to access limitations at the outlet monitoring location.

9. The field data showed low percentage removals of total phosphorus at all storm flows at an average influent concentration of 0.189 mg/L (average effluent concentration of 0.171 mg/L). We may relate the relatively poor treatment performance of the Filterra system at this location to influent characteristics for total phosphorus that are unique to the Port of Tacoma site. It appears that the Filterra system will not meet the 50 % removal performance goal when the majority of phosphorus in the runoff is expected to be in the dissolved form.

8 Laboratory Testing

1. Filterra performed laboratory testing on a scaled down version of the Filterra unit. The lab data showed an average removal from 83-91 % for TSS with influents ranging from 21 to 320 mg/L, 82-84 % for total copper with influents ranging from 0.94 to 2.3 mg/L, and 50-61 % for orthophosphate with influents ranging from 2.46 to 14.37 mg/L.

2. Filterra conducted permeability tests on the soil media.

3. Lab scale testing using Sil-Co-Sil 106 showed removals ranging from 70.1 % to 95.5 % with a median removal of 90.7 %, for influent concentrations ranging from 8.3 to 260 mg/L. Filterra ran these laboratory tests at an infiltration rate of 50 in/hr.

4. Supplemental lab testing conducted in September 2009 using Sil-Co-Sil 106 showed an average removal of 90.6 %. These laboratory tests were run at infiltration rates ranging from 25 to 150 in/hr for influent concentrations ranging from 41.6 to 252.5 mg/L.

Regression analysis results indicate that the Filterra system’s TSS removal performance is independent of influent concentration in the concentration rage evaluated at hydraulic loading rates of up to 150 in/hr.

Contact Information:

Applicant: Jeremiah Lehman
Contech Engineered Solutions, LLC.
11815 Glenn Widing Dr
Portland, OR 97220
(503) 258-3136
[email protected]

Applicant’s Website: http://www.conteches.com

Ecology web link: http://www.ecy.wa.gov/programs/wq/stormwater/newtech/index.html

Ecology: Douglas C. Howie, P.E.

Department of Ecology
Water Quality Program
(360) 407-6444
[email protected]

Date Revision
December 2009 GULD for Basic, Enhanced, and Oil granted, CULD for Phosphorus September 2011 Extended CULD for Phosphorus Treatment
September 2012 Revised design storm discussion, added Shallow System.

January 2013 Revised format to match Ecology standards, changed Filterra contact information
February 2013 Added FTIB-P system
March 2013 Added FTIB-C system
April 2013 Modified requirements for identifying appropriate size of unit

9 June 2013 Modified description of FTIB-C alternate configuration March 2014 GULD awarded for Phosphorus Treatment. GULD updated for a higher flow-rate for Basic Treatment.

June 2014 Revised sizing calculation methods
March 2015 Revised Contact Information
June 2015 CULD for Basic and Enhanced at 100 in/hr infiltration rate September 2019 GULD for Basic and Enhanced at 175 in/hr infiltration rate

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
ATTACHMENT 2

BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES

This is the cover sheet for Attachment 2.

Mark this box if this attachment is empty because the project is exempt from PDP hydromodification management requirements.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 2a Hydromodification Management Exhibit
(Required)

Included

See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.

Attachment 2b Management of Critical Coarse Sediment
Yield Areas (WMAA Exhibit is required,
additional analyses are optional)

See Section 6.2 of the BMP Design
Manual.
Exhibit showing project drainage
boundaries marked on WMAA
Critical Coarse Sediment Yield Area
Map (Required)

Optional analyses for Critical Coarse
Sediment Yield Area Determination
6.2.1 Verification of Geomorphic
Landscape Units Onsite
6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
6.2.3 Optional Additional Analysis of
Potential Critical Coarse Sediment
Yield Areas Onsite

Attachment 2c Geomorphic Assess ment of Receiving
Channels (Optional)
See Section 6.3.4 of the BMP Design
Manual.
Not performed
Included
Submitted as separate stand-alone
document

Attachment 2d Flow Control Facility Design , including
Structural BMP D rawdown Calculations
and Overflow Design Summary
(Required)
See Chapter 6 and Appendix G of the
BMP Design Manual
Included
Submitted as separate stand-alone
document

Attachment 2e Vector Control Plan (Required when
structural BMPs will not drain in 96
hours)
Included
Not required because BMPs will
drain in less than 96 hours

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
Use this checklist to ensure the required information has been included on the Hydromodification Management Exhibit:

The Hydromodification Management Exhibit must identify:

Underlying hydrologic soil group
Approximate depth to groundwater
Existing natural hydrologic features ( watercourses, seeps, springs, wetlands) Critical coarse sediment yield areas to be protected
Existing topography
Existing and proposed site drainage network and connections to drainage offsite Proposed grading
Proposed impervious features
Proposed design features and surface treatments used to minimize imperviousness Point(s) of Compliance (POC) for Hydromodification Management Existing and proposed drainage boundary and drainage area to each POC (when necessary, create separate exhibits for pre-development and post-project conditions) Structural BMPs for hydromodification management (identify location, type of BMP, and size/detail)

SDHM 3.1

PROJECT REPORT
L300-14 Pacific 12-07-2021 8/16/2022 8:33:02 AM Page 2
General Model Information
Project Name: L300-14 Pacific 12-07-2021
Site Name: Pacific
Site Address:

City:

Report Date: 8/16/2022
Gage: ESCONDID
Data Start: 10/01/1964
Data End: 09/30/2004
Timestep: Hourly
Precip Scale: 1.000
Version Date: 2020/04/07
POC Thresholds
Low Flow Threshold for POC1: 10 Percent of the 2 Year
High Flow Threshold for POC1: 10 Year
L300-14 Pacific 12-07-2021 8/16/2022 8:33:02 AM Page 3
Landuse Basin Data
Predeveloped Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,NatVeg,Flat 15.14
Pervious Total 15.14
Impervious Land Use acre
Impervious Total 0
Basin Total 15.14
Element Flows To:

Surface Interflow Groundwater

L300-14 Pacific 12-07-2021 8/16/2022 8:33:02 AM Page 4
Mitigated Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,Urban,Flat 2.54
Pervious Total 2.54
Impervious Land Use acre
IMPERVIOUS-FLAT 12.6
Impervious Total 12.6
Basin Total 15.14
Element Flows To:

Surface Interflow Groundwater
Vault 1 Vault 1
L300-14 Pacific 12-07-2021 8/16/2022 8:33:02 AM Page 5
Routing Elements
Predeveloped Routing

L300-14 Pacific 12-07-2021 8/16/2022 8:33:02 AM Page 6
Mitigated Routing
Vault 1
Width: 138.498411407562 ft.

Length: 138.498411407562 ft.

Depth: 6 ft.

Discharge Structure
Riser Height: 5 ft.

Riser Diameter: 54 in.

Notch Type: Rectangular
Notch Width: 1.387 ft.

Notch Height: 1.480 ft.

Orifice 1 Diameter: 2.791 in. Elevation:0 ft.

Element Flows To:

Outlet 1 Outlet 2
Vault Hydraulic Table
Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs)

0.0000 0.440 0.000 0.000 0.000

0.0667 0.440 0.029 0.054 0.000

0.1333 0.440 0.058 0.077 0.000

0.2000 0.440 0.088 0.094 0.000

0.2667 0.440 0.117 0.109 0.000

0.3333 0.440 0.146 0.122 0.000

0.4000 0.440 0.176 0.133 0.000

0.4667 0.440 0.205 0.144 0.000

0.5333 0.440 0.234 0.154 0.000

0.6000 0.440 0.264 0.163 0.000

0.6667 0.440 0.293 0.172 0.000

0.7333 0.440 0.322 0.181 0.000

0.8000 0.440 0.352 0.189 0.000

0.8667 0.440 0.381 0.196 0.000

0.9333 0.440 0.411 0.204 0.000

1.0000 0.440 0.440 0.211 0.000

1.0667 0.440 0.469 0.218 0.000

1.1333 0.440 0.499 0.225 0.000

1.2000 0.440 0.528 0.231 0.000

1.2667 0.440 0.557 0.237 0.000

1.3333 0.440 0.587 0.244 0.000

1.4000 0.440 0.616 0.250 0.000

1.4667 0.440 0.645 0.256 0.000

1.5333 0.440 0.675 0.261 0.000

1.6000 0.440 0.704 0.267 0.000

1.6667 0.440 0.733 0.272 0.000

1.7333 0.440 0.763 0.278 0.000

1.8000 0.440 0.792 0.283 0.000

1.8667 0.440 0.822 0.288 0.000

1.9333 0.440 0.851 0.293 0.000

2.0000 0.440 0.880 0.298 0.000

2.0667 0.440 0.910 0.303 0.000

2.1333 0.440 0.939 0.308 0.000

2.2000 0.440 0.968 0.313 0.000

2.2667 0.440 0.998 0.318 0.000

2.3333 0.440 1.027 0.322 0.000

2.4000 0.440 1.056 0.327 0.000
L300-14 Pacific 12-07-2021 8/16/2022 8:33:02 AM Page 7

2.4667 0.440 1.086 0.332 0.000

2.5333 0.440 1.115 0.336 0.000

2.6000 0.440 1.144 0.340 0.000

2.6667 0.440 1.174 0.345 0.000

2.7333 0.440 1.203 0.349 0.000

2.8000 0.440 1.233 0.353 0.000

2.8667 0.440 1.262 0.357 0.000

2.9333 0.440 1.291 0.362 0.000

3.0000 0.440 1.321 0.366 0.000

3.0667 0.440 1.350 0.370 0.000

3.1333 0.440 1.379 0.374 0.000

3.2000 0.440 1.409 0.378 0.000

3.2667 0.440 1.438 0.382 0.000

3.3333 0.440 1.467 0.385 0.000

3.4000 0.440 1.497 0.389 0.000

3.4667 0.440 1.526 0.393 0.000

3.5333 0.440 1.555 0.404 0.000

3.6000 0.440 1.585 0.505 0.000

3.6667 0.440 1.614 0.664 0.000

3.7333 0.440 1.644 0.863 0.000

3.8000 0.440 1.673 1.096 0.000

3.8667 0.440 1.702 1.358 0.000

3.9333 0.440 1.732 1.646 0.000

4.0000 0.440 1.761 1.958 0.000

4.0667 0.440 1.790 2.293 0.000

4.1333 0.440 1.820 2.648 0.000

4.2000 0.440 1.849 3.022 0.000

4.2667 0.440 1.878 3.416 0.000

4.3333 0.440 1.908 3.827 0.000

4.4000 0.440 1.937 4.255 0.000

4.4667 0.440 1.966 4.700 0.000

4.5333 0.440 1.996 5.160 0.000

4.6000 0.440 2.025 5.636 0.000

4.6667 0.440 2.055 6.127 0.000

4.7333 0.440 2.084 6.631 0.000

4.8000 0.440 2.113 7.150 0.000

4.8667 0.440 2.143 7.683 0.000

4.9333 0.440 2.172 8.228 0.000

5.0000 0.440 2.201 8.787 0.000

5.0667 0.440 2.231 9.612 0.000

5.1333 0.440 2.260 11.11 0.000

5.2000 0.440 2.289 13.06 0.000

5.2667 0.440 2.319 15.36 0.000

5.3333 0.440 2.348 17.96 0.000

5.4000 0.440 2.377 20.83 0.000

5.4667 0.440 2.407 23.93 0.000

5.5333 0.440 2.436 27.23 0.000

5.6000 0.440 2.466 30.70 0.000

5.6667 0.440 2.495 34.33 0.000

5.7333 0.440 2.524 38.08 0.000

5.8000 0.440 2.554 41.93 0.000

5.8667 0.440 2.583 45.84 0.000

5.9333 0.440 2.612 49.79 0.000

6.0000 0.440 2.642 53.76 0.000

6.0667 0.440 2.671 57.71 0.000

6.1333 0.000 0.000 61.62 0.000

L300-14 Pacific 12-07-2021 8/16/2022 8:33:02 AM Page 8
Analysis Results
POC 1
+ Predeveloped x Mitigated
Predeveloped Landuse Totals for POC #1
Total Pervious Area: 15.14
Total Impervious Area: 0
Mitigated Landuse Totals for POC #1
Total Pervious Area: 2.54
Total Impervious Area: 12.6
Flow Frequency Method: Cunnane
Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs)
2 year 3.965425
5 year 6.570597
10 year 7.571298
25 year 8.564851
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 1.46713
5 year 5.033378
10 year 6.772941
25 year 7.686606

L300-14 Pacific 12-07-2021 8/16/2022 8:33:10 AM Page 9
Duration Flows
The Facility PASSED
Flow(cfs) Predev Mit Percentage Pass/Fail

0.3965 762 749 98 Pass

0.4690 666 580 87 Pass

0.5415 611 506 82 Pass

0.6140 541 452 83 Pass

0.6864 477 408 85 Pass

0.7589 423 383 90 Pass

0.8314 375 352 93 Pass

0.9038 334 324 97 Pass

0.9763 306 302 98 Pass

1.0488 290 282 97 Pass

1.1213 278 263 94 Pass

1.1937 265 248 93 Pass

1.2662 254 229 90 Pass

1.3387 238 217 91 Pass

1.4112 227 204 89 Pass

1.4836 215 197 91 Pass

1.5561 205 188 91 Pass

1.6286 199 182 91 Pass

1.7010 191 178 93 Pass

1.7735 184 171 92 Pass

1.8460 179 162 90 Pass

1.9185 172 151 87 Pass

1.9909 168 145 86 Pass

2.0634 159 133 83 Pass

2.1359 153 130 84 Pass

2.2083 140 120 85 Pass

2.2808 129 111 86 Pass

2.3533 109 104 95 Pass

2.4258 98 100 102 Pass

2.4982 93 91 97 Pass

2.5707 92 88 95 Pass

2.6432 87 84 96 Pass

2.7157 84 81 96 Pass

2.7881 80 78 97 Pass

2.8606 74 75 101 Pass

2.9331 72 71 98 Pass

3.0055 70 70 100 Pass

3.0780 70 68 97 Pass

3.1505 66 65 98 Pass

3.2230 66 64 96 Pass

3.2954 64 60 93 Pass

3.3679 58 56 96 Pass

3.4404 55 54 98 Pass

3.5129 53 51 96 Pass

3.5853 50 46 92 Pass

3.6578 47 43 91 Pass

3.7303 46 43 93 Pass

3.8027 44 39 88 Pass

3.8752 44 38 86 Pass

3.9477 42 36 85 Pass

4.0202 41 34 82 Pass

4.0926 41 31 75 Pass

4.1651 39 31 79 Pass
L300-14 Pacific 12-07-2021 8/16/2022 8:33:10 AM Page 10

4.2376 38 29 76 Pass

4.3100 36 28 77 Pass

4.3825 34 28 82 Pass

4.4550 33 27 81 Pass

4.5275 31 27 87 Pass

4.5999 30 26 86 Pass

4.6724 29 25 86 Pass

4.7449 27 21 77 Pass

4.8174 27 20 74 Pass

4.8898 27 20 74 Pass

4.9623 25 20 80 Pass

5.0348 25 20 80 Pass

5.1072 25 18 72 Pass

5.1797 24 18 75 Pass

5.2522 24 18 75 Pass

5.3247 23 18 78 Pass

5.3971 23 18 78 Pass

5.4696 23 16 69 Pass

5.5421 23 16 69 Pass

5.6145 23 14 60 Pass

5.6870 23 14 60 Pass

5.7595 23 14 60 Pass

5.8320 23 14 60 Pass

5.9044 22 14 63 Pass

5.9769 21 13 61 Pass

6.0494 19 13 68 Pass

6.1219 18 13 72 Pass

6.1943 16 13 81 Pass

6.2668 15 12 80 Pass

6.3393 14 10 71 Pass

6.4117 13 10 76 Pass

6.4842 12 9 75 Pass

6.5567 12 9 75 Pass

6.6292 11 9 81 Pass

6.7016 10 9 90 Pass

6.7741 10 9 90 Pass

6.8466 10 8 80 Pass

6.9190 10 8 80 Pass

6.9915 9 8 88 Pass

7.0640 9 8 88 Pass

7.1365 8 7 87 Pass

7.2089 8 7 87 Pass

7.2814 7 6 85 Pass

7.3539 5 5 100 Pass

7.4264 4 4 100 Pass

7.4988 4 3 75 Pass

7.5713 4 2 50 Pass

L300-14 Pacific 12-07-2021 8/16/2022 8:33:10 AM Page 11 Water Quality
Drawdown Time Results
Pond: Vault 1
Days Stage(feet) Percent of Total Run Time
1 0.575 4.0452
2 1.576 1.6454
3 3.039 0.3992
4 0.000 N/A
5 0.000 N/A
Maximum Stage: 5.000 Drawdown Time: 03 12:26:30

L300-14 Pacific 12-07-2021 8/16/2022 8:33:10 AM Page 12 Model Default Modifications
Total of 0 changes have been made.

PERLND Changes
No PERLND changes have been made.

IMPLND Changes
No IMPLND changes have been made.

L300-14 Pacific 12-07-2021 8/16/2022 8:33:10 AM Page 13 Appendix
Predeveloped Schematic

L300-14 Pacific 12-07-2021 8/16/2022 8:33:19 AM Page 14 Mitigated Schematic

L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 15 Predeveloped UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1964 10 01 END 2004 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1

END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 L300-14 Pacific 12-07-2021.wdm
MESSU 25 PreL300-14 Pacific 12-07-2021.MES
27 PreL300-14 Pacific 12-07-2021.L61
28 PreL300-14 Pacific 12-07-2021.L62
30 POCL300-14 Pacific 12-07-20211.dat

END FILES

OPN SEQUENCE
INGRP INDELT 00:60
PERLND 28
COPY 501
DISPLY 1

END INGRP

END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1

END DISPLY
COPY

TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1

END TIMESERIES

END COPY
GENER
OPCODE
# # OPCD ***

END OPCODE
PARM
# # K ***

END PARM

END GENER
PERLND

GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***
28 D,NatVeg,Flat 1 1 1 1 27 0

END GEN-INFO
*** Section PWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 28 0 0 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 28 0 0 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO

L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 16 PWAT-PARM1
<PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 28 0 1 1 1 0 0 0 0 1 1 0 END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 28 0 3.3 0.03 100 0.05 2.5 0.915 END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 28 0 0 2 2 0 0.05 0.05 END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 28 0 0.6 0.04 1 0.3 0 END PWAT-PARM4

MON-LZETPARM
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 28 0.4 0.4 0.4 0.4 0.6 0.6 0.6 0.6 0.6 0.4 0.4 0.4

END MON-LZETPARM

MON-INTERCEP
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 28 0.1 0.1 0.1 0.1 0.06 0.06 0.06 0.06 0.06 0.1 0.1 0.1

END MON-INTERCEP
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 28 0 0 0.01 0 0.4 0.01 0 END PWAT-STATE1

END PERLND
IMPLND

GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***

END GEN-INFO
*** Section IWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL ***

END ACTIVITY

PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********

END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI ***
END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
END IWAT-PARM2

L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 17 IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
END IWAT-STATE1

END IMPLND

SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1***
PERLND 28 15.14 COPY 501 12 PERLND 28 15.14 COPY 501 13 ******Routing******

END SCHEMATIC

NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 12.1 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***

END NETWORK
RCHRES

GEN-INFO
RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out ***

END GEN-INFO
*** Section RCHRES***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG ***

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR *********

END PRINT-INFO
HYDR-PARM1
RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2

HYDR-INIT
RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><--->

END HYDR-INIT

END RCHRES

L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 18

SPEC-ACTIONS

END SPEC-ACTIONS

FTABLES

END FTABLES

EXT SOURCES
<-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 1 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 1 IMPLND 1 999 EXTNL PETINP

END EXT SOURCES

EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 12.1 WDM 501 FLOW ENGL REPL

END EXT TARGETS

MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12
PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12
MASS-LINK 13
PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13

END MASS-LINK

END RUN
L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 19 Mitigated UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1964 10 01 END 2004 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1

END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 L300-14 Pacific 12-07-2021.wdm
MESSU 25 MitL300-14 Pacific 12-07-2021.MES
27 MitL300-14 Pacific 12-07-2021.L61
28 MitL300-14 Pacific 12-07-2021.L62
30 POCL300-14 Pacific 12-07-20211.dat

END FILES

OPN SEQUENCE
INGRP INDELT 00:60
PERLND 46
IMPLND 1
RCHRES 1
COPY 1
COPY 501
DISPLY 1

END INGRP

END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Vault 1 MAX 1 2 30 9 END DISPLY-INFO1

END DISPLY
COPY

TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1

END TIMESERIES

END COPY
GENER
OPCODE
# # OPCD ***

END OPCODE
PARM
# # K ***

END PARM

END GENER
PERLND

GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***
46 D,Urban,Flat 1 1 1 1 27 0

END GEN-INFO
*** Section PWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 46 0 0 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 20 46 0 0 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO
PWAT-PARM1
<PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 46 0 1 1 1 0 0 0 0 1 1 0 END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 46 0 3.8 0.03 50 0.05 2.5 0.915 END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 46 0 0 2 2 0 0.05 0.05 END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 46 0 0.6 0.03 1 0.3 0 END PWAT-PARM4

MON-LZETPARM
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 46 0.6 0.6 0.6 0.6 0.7 0.7 0.7 0.7 0.7 0.6 0.6 0.6

END MON-LZETPARM

MON-INTERCEP
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 46 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

END MON-INTERCEP
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 46 0 0 0.15 0 1 0.05 0 END PWAT-STATE1

END PERLND
IMPLND

GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***
1 IMPERVIOUS-FLAT 1 1 1 27 0

END GEN-INFO
*** Section IWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL ***
1 0 0 1 0 0 0

END ACTIVITY

PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********
1 0 0 4 0 0 0 1 9

END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI ***
1 0 0 0 0 1
L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 21 END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
1 100 0.05 0.011 0.1
END IWAT-PARM2
IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
1 0 0
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
1 0 0
END IWAT-STATE1

END IMPLND

SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1***
PERLND 46 2.54 RCHRES 1 2 PERLND 46 2.54 RCHRES 1 3 IMPLND 1 12.6 RCHRES 1 5 ******Routing******
PERLND 46 2.54 COPY 1 12 IMPLND 1 12.6 COPY 1 15 PERLND 46 2.54 COPY 1 13 RCHRES 1 1 COPY 501 16

END SCHEMATIC

NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 12.1 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***

END NETWORK
RCHRES

GEN-INFO
RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out ***
1 Vault 1 1 1 1 1 28 0 1

END GEN-INFO
*** Section RCHRES***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO
HYDR-PARM1
L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 22 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 0 1 0 0 4 0 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.03 0.0 0.0 0.5 0.0 END HYDR-PARM2

HYDR-INIT
RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

END HYDR-INIT

END RCHRES

SPEC-ACTIONS

END SPEC-ACTIONS

FTABLES
FTABLE 1
92 4
Depth Area Volume Outflow1 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)***

0.000000 0.440354 0.000000 0.000000

0.066667 0.440354 0.029357 0.054580

0.133333 0.440354 0.058714 0.077188

0.200000 0.440354 0.088071 0.094535

0.266667 0.440354 0.117428 0.109160

0.333333 0.440354 0.146785 0.122044

0.400000 0.440354 0.176142 0.133693

0.466667 0.440354 0.205498 0.144405

0.533333 0.440354 0.234855 0.154375

0.600000 0.440354 0.264212 0.163740

0.666667 0.440354 0.293569 0.172597

0.733333 0.440354 0.322926 0.181021

0.800000 0.440354 0.352283 0.189070

0.866667 0.440354 0.381640 0.196791

0.933333 0.440354 0.410997 0.204219

1.000000 0.440354 0.440354 0.211387

1.066667 0.440354 0.469711 0.218320

1.133333 0.440354 0.499068 0.225039

1.200000 0.440354 0.528425 0.231563

1.266667 0.440354 0.557781 0.237908

1.333333 0.440354 0.587138 0.244089

1.400000 0.440354 0.616495 0.250117

1.466667 0.440354 0.645852 0.256002

1.533333 0.440354 0.675209 0.261756

1.600000 0.440354 0.704566 0.267386

1.666667 0.440354 0.733923 0.272900

1.733333 0.440354 0.763280 0.278304

1.800000 0.440354 0.792637 0.283605

1.866667 0.440354 0.821994 0.288810

1.933333 0.440354 0.851351 0.293922

2.000000 0.440354 0.880708 0.298946

2.066667 0.440354 0.910064 0.303888

2.133333 0.440354 0.939421 0.308751

2.200000 0.440354 0.968778 0.313538

2.266667 0.440354 0.998135 0.318253

2.333333 0.440354 1.027492 0.322899

2.400000 0.440354 1.056849 0.327479

2.466667 0.440354 1.086206 0.331997

2.533333 0.440354 1.115563 0.336453

2.600000 0.440354 1.144920 0.340851

2.666667 0.440354 1.174277 0.345194

2.733333 0.440354 1.203634 0.349482
L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 23

2.800000 0.440354 1.232991 0.353718

2.866667 0.440354 1.262347 0.357904

2.933333 0.440354 1.291704 0.362042

3.000000 0.440354 1.321061 0.366133

3.066667 0.440354 1.350418 0.370179

3.133333 0.440354 1.379775 0.374181

3.200000 0.440354 1.409132 0.378141

3.266667 0.440354 1.438489 0.382059

3.333333 0.440354 1.467846 0.385938

3.400000 0.440354 1.497203 0.389778

3.466667 0.440354 1.526560 0.393581

3.533333 0.440354 1.555917 0.404498

3.600000 0.440354 1.585274 0.505665

3.666667 0.440354 1.614630 0.664281

3.733333 0.440354 1.643987 0.863602

3.800000 0.440354 1.673344 1.096421

3.866667 0.440354 1.702701 1.358398

3.933333 0.440354 1.732058 1.646547

4.000000 0.440354 1.761415 1.958644

4.066667 0.440354 1.790772 2.292955

4.133333 0.440354 1.820129 2.648074

4.200000 0.440354 1.849486 3.022832

4.266667 0.440354 1.878843 3.416240

4.333333 0.440354 1.908200 3.827442

4.400000 0.440354 1.937557 4.255693

4.466667 0.440354 1.966913 4.700331

4.533333 0.440354 1.996270 5.160769

4.600000 0.440354 2.025627 5.636478

4.666667 0.440354 2.054984 6.126976

4.733333 0.440354 2.084341 6.631829

4.800000 0.440354 2.113698 7.150634

4.866667 0.440354 2.143055 7.683024

4.933333 0.440354 2.172412 8.228658

5.000000 0.440354 2.201769 8.787220

5.066667 0.440354 2.231126 9.612449

5.133333 0.440354 2.260483 11.11726

5.200000 0.440354 2.289840 13.06307

5.266667 0.440354 2.319196 15.36334

5.333333 0.440354 2.348553 17.96570

5.400000 0.440354 2.377910 20.83171

5.466667 0.440354 2.407267 23.92960

5.533333 0.440354 2.436624 27.23080

5.600000 0.440354 2.465981 30.70821

5.666667 0.440354 2.495338 34.33519

5.733333 0.440354 2.524695 38.08506

5.800000 0.440354 2.554052 41.93076

5.866667 0.440354 2.583409 45.84483

5.933333 0.440354 2.612766 49.79941

6.000000 0.440354 2.642123 53.76636

6.066667 0.440354 2.671480 57.71754
END FTABLE 1

END FTABLES

EXT SOURCES
<-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 1 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 1 IMPLND 1 999 EXTNL PETINP WDM 22 IRRG ENGL 0.7 SAME PERLND 46 EXTNL SURLI

END EXT SOURCES

EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1002 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1003 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 12.1 WDM 701 FLOW ENGL REPL L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 24 COPY 501 OUTPUT MEAN 1 1 12.1 WDM 801 FLOW ENGL REPL

END EXT TARGETS

MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 2
PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2
MASS-LINK 3
PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3
MASS-LINK 5
IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5
MASS-LINK 12
PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12
MASS-LINK 13
PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13
MASS-LINK 15
IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15
MASS-LINK 16

RCHRES ROFLOW COPY INPUT MEAN END MASS-LINK 16

END MASS-LINK

END RUN
L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 25 Predeveloped HSPF Message File

L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 26 Mitigated HSPF Message File

L300-14 Pacific 12-07-2021 8/16/2022 8:33:27 AM Page 27 Disclaimer
Legal Notice
This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2022; All Rights Reserved.

Clear Creek Solutions, Inc.
6200 Capitol Blvd. Ste F
Olympia, WA. 98501
Toll Free 1(866)943-0304
Local (360)943-0304
www.clearcreeksolutions.com
SDHM 3.1

PROJECT REPORT
L300-14 Pacific south 12-07-2021 8/16/2022 8:41:53 AM Page 2 General Model Information
Project Name: L300-14 Pacific south 12-07-2021
Site Name: Pacific
Site Address:

City:

Report Date: 8/16/2022
Gage: ESCONDID
Data Start: 10/01/1964
Data End: 09/30/2004
Timestep: Hourly
Precip Scale: 1.000
Version Date: 2020/04/07
POC Thresholds
Low Flow Threshold for POC1: 10 Percent of the 2 Year
High Flow Threshold for POC1: 10 Year
L300-14 Pacific south 12-07-2021 8/16/2022 8:41:53 AM Page 3 Landuse Basin Data
Predeveloped Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,NatVeg,Flat 1.8
Pervious Total 1.8
Impervious Land Use acre
Impervious Total 0
Basin Total 1.8
Element Flows To:

Surface Interflow Groundwater

L300-14 Pacific south 12-07-2021 8/16/2022 8:41:53 AM Page 4 Mitigated Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,Urban,Flat 0.4
Pervious Total 0.4
Impervious Land Use acre
IMPERVIOUS-FLAT 1.4
Impervious Total 1.4
Basin Total 1.8
Element Flows To:

Surface Interflow Groundwater
Vault 1 Vault 1
L300-14 Pacific south 12-07-2021 8/16/2022 8:41:53 AM Page 5 Routing Elements
Predeveloped Routing

L300-14 Pacific south 12-07-2021 8/16/2022 8:41:53 AM Page 6 Mitigated Routing
Vault 1
Width: 47.8962009473671 ft.

Length: 47.8962009473671 ft.

Depth: 6 ft.

Discharge Structure
Riser Height: 5 ft.

Riser Diameter: 54 in.

Notch Type: Rectangular
Notch Width: 0.200 ft.

Notch Height: 1.626 ft.

Orifice 1 Diameter: 0.971 in. Elevation:0 ft.

Element Flows To:

Outlet 1 Outlet 2
Vault Hydraulic Table
Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs)

0.0000 0.052 0.000 0.000 0.000

0.0667 0.052 0.003 0.006 0.000

0.1333 0.052 0.007 0.009 0.000

0.2000 0.052 0.010 0.011 0.000

0.2667 0.052 0.014 0.013 0.000

0.3333 0.052 0.017 0.014 0.000

0.4000 0.052 0.021 0.016 0.000

0.4667 0.052 0.024 0.017 0.000

0.5333 0.052 0.028 0.018 0.000

0.6000 0.052 0.031 0.019 0.000

0.6667 0.052 0.035 0.020 0.000

0.7333 0.052 0.038 0.021 0.000

0.8000 0.052 0.042 0.022 0.000

0.8667 0.052 0.045 0.023 0.000

0.9333 0.052 0.049 0.024 0.000

1.0000 0.052 0.052 0.025 0.000

1.0667 0.052 0.056 0.026 0.000

1.1333 0.052 0.059 0.027 0.000

1.2000 0.052 0.063 0.028 0.000

1.2667 0.052 0.066 0.028 0.000

1.3333 0.052 0.070 0.029 0.000

1.4000 0.052 0.073 0.030 0.000

1.4667 0.052 0.077 0.031 0.000

1.5333 0.052 0.080 0.031 0.000

1.6000 0.052 0.084 0.032 0.000

1.6667 0.052 0.087 0.033 0.000

1.7333 0.052 0.091 0.033 0.000

1.8000 0.052 0.094 0.034 0.000

1.8667 0.052 0.098 0.035 0.000

1.9333 0.052 0.101 0.035 0.000

2.0000 0.052 0.105 0.036 0.000

2.0667 0.052 0.108 0.036 0.000

2.1333 0.052 0.112 0.037 0.000

2.2000 0.052 0.115 0.037 0.000

2.2667 0.052 0.119 0.038 0.000

2.3333 0.052 0.122 0.039 0.000

2.4000 0.052 0.126 0.039 0.000
L300-14 Pacific south 12-07-2021 8/16/2022 8:41:53 AM Page 7

2.4667 0.052 0.129 0.040 0.000

2.5333 0.052 0.133 0.040 0.000

2.6000 0.052 0.136 0.041 0.000

2.6667 0.052 0.140 0.041 0.000

2.7333 0.052 0.143 0.042 0.000

2.8000 0.052 0.147 0.042 0.000

2.8667 0.052 0.151 0.043 0.000

2.9333 0.052 0.154 0.043 0.000

3.0000 0.052 0.158 0.044 0.000

3.0667 0.052 0.161 0.044 0.000

3.1333 0.052 0.165 0.045 0.000

3.2000 0.052 0.168 0.045 0.000

3.2667 0.052 0.172 0.046 0.000

3.3333 0.052 0.175 0.046 0.000

3.4000 0.052 0.179 0.049 0.000

3.4667 0.052 0.182 0.066 0.000

3.5333 0.052 0.186 0.089 0.000

3.6000 0.052 0.189 0.116 0.000

3.6667 0.052 0.193 0.148 0.000

3.7333 0.052 0.196 0.182 0.000

3.8000 0.052 0.200 0.219 0.000

3.8667 0.052 0.203 0.257 0.000

3.9333 0.052 0.207 0.298 0.000

4.0000 0.052 0.210 0.339 0.000

4.0667 0.052 0.214 0.382 0.000

4.1333 0.052 0.217 0.425 0.000

4.2000 0.052 0.221 0.469 0.000

4.2667 0.052 0.224 0.514 0.000

4.3333 0.052 0.228 0.558 0.000

4.4000 0.052 0.231 0.607 0.000

4.4667 0.052 0.235 0.662 0.000

4.5333 0.052 0.238 0.719 0.000

4.6000 0.052 0.242 0.778 0.000

4.6667 0.052 0.245 0.838 0.000

4.7333 0.052 0.249 0.899 0.000

4.8000 0.052 0.252 1.253 0.000

4.8667 0.052 0.256 1.339 0.000

4.9333 0.052 0.259 1.426 0.000

5.0000 0.052 0.263 1.515 0.000

5.0667 0.052 0.266 2.337 0.000

5.1333 0.052 0.270 3.840 0.000

5.2000 0.052 0.273 5.783 0.000

5.2667 0.052 0.277 8.080 0.000

5.3333 0.052 0.280 10.68 0.000

5.4000 0.052 0.284 13.54 0.000

5.4667 0.052 0.287 16.63 0.000

5.5333 0.052 0.291 19.93 0.000

5.6000 0.052 0.294 23.41 0.000

5.6667 0.052 0.298 27.03 0.000

5.7333 0.052 0.301 30.78 0.000

5.8000 0.052 0.305 34.62 0.000

5.8667 0.052 0.309 38.53 0.000

5.9333 0.052 0.312 42.49 0.000

6.0000 0.052 0.316 46.45 0.000

6.0667 0.052 0.319 50.40 0.000

6.1333 0.000 0.000 54.30 0.000

L300-14 Pacific south 12-07-2021 8/16/2022 8:41:53 AM Page 8 Analysis Results
POC 1
+ Predeveloped x Mitigated
Predeveloped Landuse Totals for POC #1
Total Pervious Area: 1.8
Total Impervious Area: 0
Mitigated Landuse Totals for POC #1
Total Pervious Area: 0.4
Total Impervious Area: 1.4
Flow Frequency Method: Cunnane
Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs)
2 year 0.471451
5 year 0.781181
10 year 0.900154
25 year 1.018278
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 0.170547
5 year 0.584245
10 year 0.780762
25 year 0.944355

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:02 AM Page 9 Duration Flows
The Facility PASSED
Flow(cfs) Predev Mit Percentage Pass/Fail

0.0471 762 727 95 Pass

0.0558 677 563 83 Pass

0.0644 611 481 78 Pass

0.0730 546 430 78 Pass

0.0816 479 401 83 Pass

0.0902 425 365 85 Pass

0.0988 379 338 89 Pass

0.1075 335 311 92 Pass

0.1161 307 292 95 Pass

0.1247 290 276 95 Pass

0.1333 278 256 92 Pass

0.1419 265 245 92 Pass

0.1505 254 227 89 Pass

0.1592 239 211 88 Pass

0.1678 228 202 88 Pass

0.1764 216 194 89 Pass

0.1850 205 184 89 Pass

0.1936 200 180 90 Pass

0.2022 191 171 89 Pass

0.2109 184 166 90 Pass

0.2195 179 159 88 Pass

0.2281 172 151 87 Pass

0.2367 169 142 84 Pass

0.2453 159 128 80 Pass

0.2539 155 121 78 Pass

0.2626 141 117 82 Pass

0.2712 129 107 82 Pass

0.2798 109 98 89 Pass

0.2884 98 95 96 Pass

0.2970 93 91 97 Pass

0.3056 92 85 92 Pass

0.3142 87 81 93 Pass

0.3229 84 77 91 Pass

0.3315 80 77 96 Pass

0.3401 74 73 98 Pass

0.3487 72 70 97 Pass

0.3573 70 68 97 Pass

0.3659 70 67 95 Pass

0.3746 67 64 95 Pass

0.3832 66 61 92 Pass

0.3918 64 57 89 Pass

0.4004 59 55 93 Pass

0.4090 55 49 89 Pass

0.4176 53 46 86 Pass

0.4263 50 43 86 Pass

0.4349 47 43 91 Pass

0.4435 46 41 89 Pass

0.4521 44 38 86 Pass

0.4607 44 36 81 Pass

0.4693 42 32 76 Pass

0.4780 41 31 75 Pass

0.4866 41 30 73 Pass

0.4952 39 30 76 Pass
L300-14 Pacific south 12-07-2021 8/16/2022 8:42:02 AM Page 10

0.5038 38 28 73 Pass

0.5124 36 28 77 Pass

0.5210 34 28 82 Pass

0.5297 33 26 78 Pass

0.5383 31 25 80 Pass

0.5469 30 23 76 Pass

0.5555 29 21 72 Pass

0.5641 27 20 74 Pass

0.5727 27 20 74 Pass

0.5814 27 19 70 Pass

0.5900 25 19 76 Pass

0.5986 25 18 72 Pass

0.6072 25 18 72 Pass

0.6158 25 18 72 Pass

0.6244 24 18 75 Pass

0.6331 23 16 69 Pass

0.6417 23 16 69 Pass

0.6503 23 15 65 Pass

0.6589 23 15 65 Pass

0.6675 23 14 60 Pass

0.6761 23 14 60 Pass

0.6847 23 13 56 Pass

0.6934 23 13 56 Pass

0.7020 22 13 59 Pass

0.7106 21 13 61 Pass

0.7192 19 13 68 Pass

0.7278 18 13 72 Pass

0.7364 16 12 75 Pass

0.7451 15 12 80 Pass

0.7537 14 11 78 Pass

0.7623 13 11 84 Pass

0.7709 12 9 75 Pass

0.7795 12 9 75 Pass

0.7881 11 8 72 Pass

0.7968 11 8 72 Pass

0.8054 10 8 80 Pass

0.8140 10 8 80 Pass

0.8226 10 8 80 Pass

0.8312 9 8 88 Pass

0.8398 9 8 88 Pass

0.8485 8 8 100 Pass

0.8571 8 7 87 Pass

0.8657 7 5 71 Pass

0.8743 5 5 100 Pass

0.8829 4 4 100 Pass

0.8915 4 4 100 Pass

0.9002 4 4 100 Pass

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:02 AM Page 11 Water Quality
Drawdown Time Results
Pond: Vault 1
Days Stage(feet) Percent of Total Run Time
1 1.127 2.4254
2 2.448 0.7485
3 0.000 N/A
4 0.000 N/A
5 0.000 N/A
Maximum Stage: 5.000 Drawdown Time: 02 20:37:30

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:02 AM Page 12 Model Default Modifications
Total of 0 changes have been made.

PERLND Changes
No PERLND changes have been made.

IMPLND Changes
No IMPLND changes have been made.

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:02 AM Page 13 Appendix
Predeveloped Schematic

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:10 AM Page 14 Mitigated Schematic

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 15 Predeveloped UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1964 10 01 END 2004 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1

END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 L300-14 Pacific south 12-07-2021.wdm
MESSU 25 PreL300-14 Pacific south 12-07-2021.MES 27 PreL300-14 Pacific south 12-07-2021.L61
28 PreL300-14 Pacific south 12-07-2021.L62
30 POCL300-14 Pacific south 12-07-20211.dat

END FILES

OPN SEQUENCE
INGRP INDELT 00:60
PERLND 28
COPY 501
DISPLY 1

END INGRP

END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1

END DISPLY
COPY

TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1

END TIMESERIES

END COPY
GENER
OPCODE
# # OPCD ***

END OPCODE
PARM
# # K ***

END PARM

END GENER
PERLND

GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***
28 D,NatVeg,Flat 1 1 1 1 27 0

END GEN-INFO
*** Section PWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 28 0 0 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 28 0 0 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 16 PWAT-PARM1
<PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 28 0 1 1 1 0 0 0 0 1 1 0 END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 28 0 3.3 0.03 100 0.05 2.5 0.915 END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 28 0 0 2 2 0 0.05 0.05 END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 28 0 0.6 0.04 1 0.3 0 END PWAT-PARM4

MON-LZETPARM
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 28 0.4 0.4 0.4 0.4 0.6 0.6 0.6 0.6 0.6 0.4 0.4 0.4

END MON-LZETPARM

MON-INTERCEP
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 28 0.1 0.1 0.1 0.1 0.06 0.06 0.06 0.06 0.06 0.1 0.1 0.1

END MON-INTERCEP
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 28 0 0 0.01 0 0.4 0.01 0 END PWAT-STATE1

END PERLND
IMPLND

GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***

END GEN-INFO
*** Section IWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL ***

END ACTIVITY

PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********

END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI ***
END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
END IWAT-PARM2

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 17 IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
END IWAT-STATE1

END IMPLND

SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1***
PERLND 28 1.8 COPY 501 12 PERLND 28 1.8 COPY 501 13 ******Routing******

END SCHEMATIC

NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 12.1 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***

END NETWORK
RCHRES

GEN-INFO
RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out ***

END GEN-INFO
*** Section RCHRES***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG ***

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR *********

END PRINT-INFO
HYDR-PARM1
RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2

HYDR-INIT
RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><--->

END HYDR-INIT

END RCHRES

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 18

SPEC-ACTIONS

END SPEC-ACTIONS

FTABLES

END FTABLES

EXT SOURCES
<-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 1 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 1 IMPLND 1 999 EXTNL PETINP

END EXT SOURCES

EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 12.1 WDM 501 FLOW ENGL REPL

END EXT TARGETS

MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12
PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12
MASS-LINK 13
PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13

END MASS-LINK

END RUN
L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 19 Mitigated UCI File
RUN
GLOBAL
WWHM4 model simulation
START 1964 10 01 END 2004 09 30
RUN INTERP OUTPUT LEVEL 3 0
RESUME 0 RUN 1 UNIT SYSTEM 1

END GLOBAL
FILES
<File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 L300-14 Pacific south 12-07-2021.wdm
MESSU 25 MitL300-14 Pacific south 12-07-2021.MES 27 MitL300-14 Pacific south 12-07-2021.L61
28 MitL300-14 Pacific south 12-07-2021.L62
30 POCL300-14 Pacific south 12-07-20211.dat

END FILES

OPN SEQUENCE
INGRP INDELT 00:60
PERLND 46
IMPLND 1
RCHRES 1
COPY 1
COPY 501
DISPLY 1

END INGRP

END OPN SEQUENCE
DISPLY
DISPLY-INFO1
# - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Vault 1 MAX 1 2 30 9 END DISPLY-INFO1

END DISPLY
COPY

TIMESERIES
# - # NPT NMN ***
1 1 1
501 1 1

END TIMESERIES

END COPY
GENER
OPCODE
# # OPCD ***

END OPCODE
PARM
# # K ***

END PARM

END GENER
PERLND

GEN-INFO
<PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***
46 D,Urban,Flat 1 1 1 1 27 0

END GEN-INFO
*** Section PWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 46 0 0 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 20 46 0 0 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO
PWAT-PARM1
<PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 46 0 1 1 1 0 0 0 0 1 1 0 END PWAT-PARM1
PWAT-PARM2
<PLS > PWATER input info: Part 2 ***
# - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 46 0 3.8 0.03 50 0.05 2.5 0.915 END PWAT-PARM2
PWAT-PARM3
<PLS > PWATER input info: Part 3 ***
# - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 46 0 0 2 2 0 0.05 0.05 END PWAT-PARM3
PWAT-PARM4
<PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 46 0 0.6 0.03 1 0.3 0 END PWAT-PARM4

MON-LZETPARM
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 46 0.6 0.6 0.6 0.6 0.7 0.7 0.7 0.7 0.7 0.6 0.6 0.6

END MON-LZETPARM

MON-INTERCEP
<PLS > PWATER input info: Part 3 ***
# - # JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC *** 46 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

END MON-INTERCEP
PWAT-STATE1
<PLS > *** Initial conditions at start of simulation
ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 ***
# - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 46 0 0 0.15 0 1 0.05 0 END PWAT-STATE1

END PERLND
IMPLND

GEN-INFO
<PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out ***
1 IMPERVIOUS-FLAT 1 1 1 27 0

END GEN-INFO
*** Section IWATER***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL ***
1 0 0 1 0 0 0

END ACTIVITY

PRINT-INFO
<ILS > ******** Print-flags ******** PIVL PYR
# - # ATMP SNOW IWAT SLD IWG IQAL *********
1 0 0 4 0 0 0 1 9

END PRINT-INFO
IWAT-PARM1
<PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI ***
1 0 0 0 0 1
L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 21 END IWAT-PARM1
IWAT-PARM2
<PLS > IWATER input info: Part 2 ***
# - # *** LSUR SLSUR NSUR RETSC
1 100 0.05 0.011 0.1
END IWAT-PARM2
IWAT-PARM3
<PLS > IWATER input info: Part 3 ***
# - # ***PETMAX PETMIN
1 0 0
END IWAT-PARM3
IWAT-STATE1
<PLS > *** Initial conditions at start of simulation
# - # *** RETS SURS
1 0 0
END IWAT-STATE1

END IMPLND

SCHEMATIC
<-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1***
PERLND 46 0.4 RCHRES 1 2 PERLND 46 0.4 RCHRES 1 3 IMPLND 1 1.4 RCHRES 1 5 ******Routing******
PERLND 46 0.4 COPY 1 12 IMPLND 1 1.4 COPY 1 15 PERLND 46 0.4 COPY 1 13 RCHRES 1 1 COPY 501 16

END SCHEMATIC

NETWORK
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 12.1 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # ***

END NETWORK
RCHRES

GEN-INFO
RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out ***
1 Vault 1 1 1 1 1 28 0 1

END GEN-INFO
*** Section RCHRES***

ACTIVITY
<PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0

END ACTIVITY

PRINT-INFO
<PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9

END PRINT-INFO
HYDR-PARM1
L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 22 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 0 1 0 0 4 0 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1
HYDR-PARM2
# - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.01 0.0 0.0 0.5 0.0 END HYDR-PARM2

HYDR-INIT
RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

END HYDR-INIT

END RCHRES

SPEC-ACTIONS

END SPEC-ACTIONS

FTABLES
FTABLE 1
92 4
Depth Area Volume Outflow1 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)***

0.000000 0.052664 0.000000 0.000000

0.066667 0.052664 0.003511 0.006606

0.133333 0.052664 0.007022 0.009343

0.200000 0.052664 0.010533 0.011442

0.266667 0.052664 0.014044 0.013212

0.333333 0.052664 0.017555 0.014772

0.400000 0.052664 0.021066 0.016182

0.466667 0.052664 0.024577 0.017478

0.533333 0.052664 0.028087 0.018685

0.600000 0.052664 0.031598 0.019819

0.666667 0.052664 0.035109 0.020891

0.733333 0.052664 0.038620 0.021910

0.800000 0.052664 0.042131 0.022885

0.866667 0.052664 0.045642 0.023819

0.933333 0.052664 0.049153 0.024718

1.000000 0.052664 0.052664 0.025586

1.066667 0.052664 0.056175 0.026425

1.133333 0.052664 0.059686 0.027238

1.200000 0.052664 0.063197 0.028028

1.266667 0.052664 0.066708 0.028796

1.333333 0.052664 0.070219 0.029544

1.400000 0.052664 0.073730 0.030273

1.466667 0.052664 0.077241 0.030986

1.533333 0.052664 0.080752 0.031682

1.600000 0.052664 0.084262 0.032364

1.666667 0.052664 0.087773 0.033031

1.733333 0.052664 0.091284 0.033685

1.800000 0.052664 0.094795 0.034327

1.866667 0.052664 0.098306 0.034957

1.933333 0.052664 0.101817 0.035575

2.000000 0.052664 0.105328 0.036184

2.066667 0.052664 0.108839 0.036782

2.133333 0.052664 0.112350 0.037370

2.200000 0.052664 0.115861 0.037950

2.266667 0.052664 0.119372 0.038520

2.333333 0.052664 0.122883 0.039083

2.400000 0.052664 0.126394 0.039637

2.466667 0.052664 0.129905 0.040184

2.533333 0.052664 0.133416 0.040723

2.600000 0.052664 0.136927 0.041256

2.666667 0.052664 0.140437 0.041781

2.733333 0.052664 0.143948 0.042300
L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 23

2.800000 0.052664 0.147459 0.042813

2.866667 0.052664 0.150970 0.043320

2.933333 0.052664 0.154481 0.043821

3.000000 0.052664 0.157992 0.044316

3.066667 0.052664 0.161503 0.044805

3.133333 0.052664 0.165014 0.045290

3.200000 0.052664 0.168525 0.045769

3.266667 0.052664 0.172036 0.046243

3.333333 0.052664 0.175547 0.046713

3.400000 0.052664 0.179058 0.049930

3.466667 0.052664 0.182569 0.066030

3.533333 0.052664 0.186080 0.089042

3.600000 0.052664 0.189591 0.116796

3.666667 0.052664 0.193102 0.148191

3.733333 0.052664 0.196612 0.182500

3.800000 0.052664 0.200123 0.219188

3.866667 0.052664 0.203634 0.257831

3.933333 0.052664 0.207145 0.298080

4.000000 0.052664 0.210656 0.339638

4.066667 0.052664 0.214167 0.382244

4.133333 0.052664 0.217678 0.425669

4.200000 0.052664 0.221189 0.469706

4.266667 0.052664 0.224700 0.514167

4.333333 0.052664 0.228211 0.558877

4.400000 0.052664 0.231722 0.607255

4.466667 0.052664 0.235233 0.662491

4.533333 0.052664 0.238744 0.719424

4.600000 0.052664 0.242255 0.778004

4.666667 0.052664 0.245766 0.838186

4.733333 0.052664 0.249277 0.899927

4.800000 0.052664 0.252787 1.253683

4.866667 0.052664 0.256298 1.339039

4.933333 0.052664 0.259809 1.426313

5.000000 0.052664 0.263320 1.515462

5.066667 0.052664 0.266831 2.337930

5.133333 0.052664 0.270342 3.839994

5.200000 0.052664 0.273853 5.783084

5.266667 0.052664 0.277364 8.080651

5.333333 0.052664 0.280875 10.68031

5.400000 0.052664 0.284386 13.54365

5.466667 0.052664 0.287897 16.63888

5.533333 0.052664 0.291408 19.93744

5.600000 0.052664 0.294919 23.41223

5.666667 0.052664 0.298430 27.03660

5.733333 0.052664 0.301941 30.78388

5.800000 0.052664 0.305451 34.62700

5.866667 0.052664 0.308962 38.53851

5.933333 0.052664 0.312473 42.49053

6.000000 0.052664 0.315984 46.45495

6.066667 0.052664 0.319495 50.40361
END FTABLE 1

END FTABLES

EXT SOURCES
<-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 1 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 1 IMPLND 1 999 EXTNL PETINP WDM 22 IRRG ENGL 0.7 SAME PERLND 46 EXTNL SURLI

END EXT SOURCES

EXT TARGETS
<-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1002 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1003 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 12.1 WDM 701 FLOW ENGL REPL L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 24 COPY 501 OUTPUT MEAN 1 1 12.1 WDM 801 FLOW ENGL REPL

END EXT TARGETS

MASS-LINK
<Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 2
PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2
MASS-LINK 3
PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3
MASS-LINK 5
IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5
MASS-LINK 12
PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12
MASS-LINK 13
PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13
MASS-LINK 15
IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15
MASS-LINK 16

RCHRES ROFLOW COPY INPUT MEAN END MASS-LINK 16

END MASS-LINK

END RUN
L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 25 Predeveloped HSPF Message File

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 26 Mitigated HSPF Message File

L300-14 Pacific south 12-07-2021 8/16/2022 8:42:18 AM Page 27 Disclaimer
Legal Notice
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PACIFIC

PCCSYA - NONE
Legend
0 06073C
06073C
06073C
Creek
Creek
Enterprise Rent-A-Car
Feature 1
Feature 2
Feature 3
Feature 4
Lake
San
San
San Luis Rey River
Yes
700 ft
N ➤ ➤
N
Image Landsat / Copernicus
Image Landsat / Copernicus
Image Landsat / Copernicus

REVISED PRELIMINARY Geotechnical Evaluation
FOR

PACIFIC GPA/R EZONE
Northwest Corner of Linda Vista Drive & Los Posas Road

SAN MARCOS , CALIFORNIA

P

REPARED FOR

The Las Posas Owner LPV, LLC, a Delaware limited liability company 2235 Encinitas Boulevard, Suite 216
Encinitas, California 92024

P

REPARED BY

GEO TEK , INC .
1384 POINSETTIA AVENUE , SUITE A
VISTA , CALIFORNIA 92081

PROJECT NO. 36 49 -SD JANUARY 4, 202 2

GEOTECHNICAL | ENVIRONMENTAL | MATERIALS

January 4, 2022
Project No. 3649-SD
The Las Posas Owner LPV, LLC,
a Delaware limited liability company
2235 Encinitas Boulevard, Suite 216
Encinitas, California 92024

Attention: Mr. Greg Waite

Subject: Revised Preliminary Geotechnical Evaluatio n
Pacific GPA/Rezone
Northwest Corner of Linda Vista Drive & Los Posas Road
San Marcos, California

Dear Mr. Waite:

We are pleased to provide herein the results of our preliminary geotechnical evaluation for the subject property located in the city of San Marcos, California. This report presents the results of our evaluation and provides prelimin ary geotechnical recommendations for future earthwork, foundation design, and constructi on. In our opinion, the property appears feasible from a geotechnical viewpoint prov ided that the recommendations included herein are incorporated into the future design and construction phases of property development. The opportunity to be of service is s incerely appreciated. If you should have any questions, please do not hesitate to call our office.

Respectfully submitted,
GeoTek, Inc.

Bruce A. Hick
GE 2284
Geotechnical Engineer

Christopher D. Livesey
CEG 2733
Project Geologist

Edward LaMont
CEG 1892
Principal Geologist

Distribution: (1) Addressee via email
THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page i

TABLE OF CONTENTS

1. PURPOSE AND SCOPE OF SERVICES ................................................................................................. 1

2. PROPERTY DESCRIPTION AND PROPOSED DEVELOPMENT .................................................. 1

2.1 Property Description ..................................................................................................... .................... 1

2.2 Future Development ..................................................................................................... .................... 2

3. FIELD EXPLORATION AND LABORATORY TESTING ................................................................. 3

3.1 Field Exploration ..................................................................................................... .......................... 3

3.2 Laboratory Testing ..................................................................................................... ....................... 4

4. GEOLOGIC AND SOILS CONDITIONS ............................................................................................... 5

4.1 Regional Setting ..................................................................................................... ........................... 5

4.2 EARTH MATERIALS .................................................. ................................................... .................... 5

4.2.1 Undocumented Fill (Not Mapped) ..................................................................................................... 5

4.2.2 Alluvium (Map Symbol Qal) .................................................. ................................................... ......... 5

4.2.3 Tertiary Santiago Formation (Map Symbol Tsa) .................................................. ............................... 6

4.3 SURFACE WATER AND GROUNDWATER ........................................................................................ 6

4.3.1 Surface Water ..................................................................................................... ............................. 6

4.3.2 Groundwater ..................................................................................................... ............................... 6

4.4 EARTHQUAKE HAZARDS ..................................................................................................... ........... 6

4.4.1 Surface Fault Rupture ..................................................................................................... .................. 6

4.4.2 Liquefaction/Seismic Settlement ................................................... ................................................... ... 6

4.4.3 Other Seismic Hazards ..................................................................................................... ................ 7

5. CONCLUSIONS AND RECOMMENDATIONS .................................................. ................................ 7

5.1 General ..................................................................................................... ....................................... 7

5.2 EARTHWORK CONSIDERATIONS .................................................. ................................................. 7

5.2.1 General ..................................................................................................... ....................................... 7

5.2.2 Property Clearing and Preparation ..................................................................................................... 8

5.2.3 Remedial Grading ..................................................................................................... ........................ 8

5.2.4 Engineered Fill ..................................................................................................... ............................. 8

5.2.5 Excavation Characteristics ..................................................................................................... ............ 9

5.2.6 Shrinkage and Bulking ..................................................................................................... ................. 9

5.2.7 Trench Excavations and Backfill .................................................. ................................................... ... 9

5.3 DESIGN RECOMMENDATIONS ..................................................................................................... 10

5.3.1 Stormwater Infiltration ..................................................................................................... ............... 10

5.3.2 Foundation Design Criteria ..................................................................................................... ......... 10

5.3.3 Underslab Moisture Membrane ................................................... ................................................... . 12

5.3.4 Miscellaneous Foundation Recommendations ................................................................................... 13

5.3.5 Foundation Set Backs ................................................... ................................................... ................ 13

5.3.6 Seismic Design Parameters .................................................. ................................................... ........ 14

5.3.7 Soil Sulfate Content ..................................................................................................... ................... 14

5.3.8 Preliminary Pavement Design ..................................................................................................... ..... 14

5.4 RETAINING WALL DESIGN AND CONSTRUCTION ........................................................................ 15

5.4.1 General Design Criteria ..................................................................................................... .............. 15

5.4.2 Restrained Retaining Walls .................................................. ................................................... ........ 16

5.4.3 Wall Backfill and Drainage .................................................. ................................................... ........ 17

5.5 POST CONSTRUCTION CONSIDERATIONS .................................................. ................................. 17

5.5.1 Landscape Maintenance and Planting .............................................................................................. 17

5.5.2 Drainage ..................................................................................................... ................................... 18

5.6 PLAN REVIEW AND CONSTRUCTION OBSERVATIONS .................................................. ............... 18 THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page ii

TABLE OF CONTENTS

6. LIMITATIONS ..................................................................................................... ....................................... 19

7. SELECTED REFERENCES ..................................................................................................... .................. 20

ENCLOSURES
Figure 1 – Site Location Map
Figure 2 – Boring Location Map

Appendix A – Exploratory Boring Logs and Infiltration Worksheets Appendix B – Results of Laboratory Testing
Appendix C – General Earthwork Grading Guidelines

THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 1

1. PURPOSE AND SCOPE OF SERVICES
The purpose of this study was to evaluate the geote chnical conditions on the site. Services provided for this study included the following:

 Research and review of available geologic and geotechnical data, and general information pertinent to the property.
 Excavation of four (4) hollow stem auger borings on site and collection of bulk and relatively undisturbed soil samples for subsequent laboratory testing.  Two percolation test borings and infiltration analyses.  Laboratory testing of the soil samples collected during the field investigation.  Review and evaluation of seismicity, and
 Compilation of this geotechnical report which prese nts our findings of pertinent geotechnical conditions and geotechnical recommenda tions for future property development.

2. PROPERTY DESCRIPTION AND PROPOSED DEVELOPMENT

2.1 Property Description

The subject property is located at the northern corner of Linda Vista Drive and Los Posas Road in the City of San Marcos, San Diego County, California (see Figure 1). The property is bounded to the southwest by Linda Vista Drive, to the south east by Los Posas Road, to the northeast by La Mirada Drive, and to the northwest by Pacific St reet. Surface conditions generally consist of rolling unimproved earthen terrain, with native grasses and vegetation. The Site is relatively flat, ranging in elevation from approximately 527 feet ab ove mean sea level (amsl) in the southeast potion of the project area to 551 feet in the northwest corner of the project Site.

THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 2

2.2 Future Development
The approximately 33-acre Project site is an infill site located in the western portion of the City of San Marcos, at the northwest corner of Las Posas Road and Linda Vista Drive, comprised of Assessor’s Parcel Numbers (APNs) 219-222-01, 219-22 2-02, 219-222-03, and 219-222-04. La Mirada Road abuts the site’s northern boundary, whi le Pacific Street abuts the property’s western boundary. The Grand Plaza shopping center i s located directly across Las Posas Drive.

Light industrial uses are adjacent to the Project site’s northern, southern, and western boundary, and Bradley Park is located across from the Project site’s southwestern corner. Single- and multi- family residential uses are located to the west and south of Bradley Park.

The Project would allow for the development of 495 residential units, including a mix of five- story podium apartments, three-story rowhomes, thre e-story villas, and four-story affordable flats on approximately 16.5 acres within the 33-acr e Project site (Figure 3). 74 of the 495 total units (15 percent of the total) would be designated as deed-restricted affordable units. The proposed housing types are outlined below:

Housing Type Number of Units Square Feet
Apartments 137 740 – 1,579 sf
Rowhomes 154 1,200 - 1,890 sf
Villas 130 1,272 – 1,832 sf
Affordable Flats 74 512 – 924 sf

The Project would also include a total of 996 parki ng spaces and an 18,000 square foot community commons area. The proposed project also includes landscaping, bio-retention areas and circulation improvements. The remaining 16.7 ac res of the 33.2-acre project site would be preserved and restored open space and habitat area.

The Project would have a density of approximately 3 0 dwelling units per acre (DU/AC) not including the proposed open space and habitat area. With the open space area included, the density of the proposed project would be approximately 15 DU/AC.

The Project proposes a General Plan Amendment, Rezo ne, Specific Plan, Tentative Map, and Multi-Family Site Development Plan. The General Pla n Amendment and Rezone would change the General Plan designation and Zoning from Industrial (I) to Specific Plan Area. The Tentative Map presents specific lot configurations for the site. The Multi-Family Site Development Plan will configure the site for multi family dwelling units, street configuration, infrastructure, recreational open space, and private open space.

THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 3

Structural loading information was not available at the time of this report submittal but should be provided to GeoTek once determined. For this report, we have assumed a maximum column load of 150 kips for the planned structures.

As planning progresses and additional or revised plans become available, they should be provided to GeoTek for review and comment. If plans vary si gnificantly, additional geotechnical field exploration, laboratory testing and engineering ana lyses may be necessary to provide specific earthwork recommendations and geotechnical design parameters for actual development plans.

3. FIELD EXPLORATION AND LABORATORY TESTING

3.1 Field Exploration

Our field study conducted on September 29, 2020 con sisted of a reconnaissance, excavation of geotechnical hollow stem auger borings B-3 through B-6 to depths of about 19-½ feet below grade and 2 percolation test borings P-1 and P-2 to depths of about 3 feet below grade. The borings were drilled with a truck mounted rubber tire CME-75 drilling rig and included collection of bulk and relatively undisturbed driven soil samples for subsequent laboratory testing. Proposed borings B-1 and B-2 were not performed due to biolo gical constraints and omitted from this report. Several variations of proposed boring loca tions were presented to California Fish and Wildlife (CFW), however, CFW only authorized the locat ions presented on Figure 2. A representative from our firm visually logged the borings and collected soil samples for laboratory analysis. Approximate locations of exploration loc ations are presented on the Boring Location Map, Figure 2. A description of material encountered in the borings is included in Appendix A.

3.2 Percolation and Infiltration Testing

Borings P-1 and P-2 were advanced to approximate depths of 3 feet below existing grade with an 8-inch diameter and converted to a dry well for percolation testing approximately 5-10 feet away from boring location B-6. Following completion of the boring excavations, percolation testing was performed by a representative from our firm in general conformance with the city of San Marcos BMP Design Manual. The boreholes were preso aked over-night and the testing was performed the following day. Percolation testing was performed by adding potable water to the borings, recording the initial depth to water and a llowing the water to percolate for 30 minutes and the depth to water was measured. Water was generally added to each boring following each reading increment. In general, the percolation testing was performed for approximately 6 hours THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 4

to allow rates to stabilize. Results of the final percolation increment were used to calculate an infiltration rate in inches per hour via the Porchet method.

For design of shallow infiltration basins, converti ng percolation rates to infiltration rates via the Porchet method is generally acceptable and appropriate, as this method factors out the sidewall component of the percolation results and represents the bottom conditions of a shallow basin (infiltration). Therefore, the percolation data fo r borings P-1 and P-2 were converted via the Porchet method. This method is consistent with the guidelines referenced in the City of San Marcos BMP Design Manual. Results of our infiltrat ion analysis without a factor of safety are presented in the follow table for each of the test areas.

Location Depth
(inches )
Infiltration Rate
(inches per hour) *
P-1 35.75 0. 07
P-2 34.75 0. 07
* Rate was converted to an infiltration rate via the Porchet method

Copies of infiltration conversion sheets are included in Appendix A.

The material exposed along the boring sidewalls and at the bottom of P-1 and P-2 were native soils. The tests performed and reported are indicative of native soils. At the time of investigation, groundwater was not encountered in the vicinity.

Over the lifetime of the storm water disposal areas, the percolation rates may be affected by silt build up and biological activities, as well as loca l variations in soil conditions. An appropriate factor of safety used to compute the design percola tion rate should be considered at the discretion of the design engineer and acceptance of the plan reviewer.

3.2 Laboratory Testing
Laboratory testing was performed on bulk and relatively undisturbed soil samples collected during the field explorations. The purpose of the laborat ory testing was to evaluate their physical and chemical properties for use in engineering design a nd analysis. Results of the laboratory testing program, along with a brief description and relevan t information regarding testing procedures, are included in Appendix B.

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4. GEOLOGIC AND SOILS CONDITIONS

4.1 Regional Setting
The subject property is located in the Peninsular R anges geomorphic province. The Peninsular Ranges province is one of the largest geomorphic un its in western North America. Basically, it extends roughly 975 miles from the north and northe asterly adjacent the Transverse Ranges geomorphic province to the tip of Baja California. This province varies in width from about 30 to 100 miles. It is bounded on the west by the Pac ific Ocean, on the south by the Gulf of California and on the east by the Colorado Desert Province.

The Peninsular Ranges are essentially a series of n orthwest-southeast oriented fault blocks.

Several major fault zones are found in this province. The Elsinore Fault zone and the San Jacinto Fault zones trend northwest-southeast and are found in the near the middle of the province. The San Andreas Fault zone borders the northeasterly ma rgin of the province. The Newport- Inglewood-Rose Canyon Fault zone meanders the southwest margin of the province, but can be more appropriately defined by the Pacific Ocean. N o faults are shown in the immediate vicinity on the map reviewed for the area.

4.2 EARTH MATERIALS
A brief description of the earth materials encounte red during our subsurface exploration is presented in the following sections. Based on our field observations and review of published geologic maps the subject property is locally underlain by recent alluvium and Santiago Formation bedrock.

4.2.1 Undocumented Fill (Not Mapped)
Undocumented fill soils were observed as sporadic e nd-dump piles from illegal dumping. These soils are not considered suitable for support of st ructural improvements but may be re-used as engineered fill if properly processed and placed.

4.2.2 Alluvium (Map Symbol Qal)
The most recent regional geologic map reviewed show ed the geology (Kennedy, 2007) for the eastern portion of the area along Los Posas Road to be alluvial deposits, however, based on our evaluation, alluvium appears to be limited to a smaller extent along a natural drainage swale along Los Posas Road. As encountered in boring B-6, the alluvium generally consisted of silty fine sands.

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4.2.3 Tertiary Santiago Formation (Map Symbol Tsa)
The most recently dated regional geologic map showi ng the overall geology (Kennedy, 2007), indicates Santiago Formation sedimentary bedrock at the surface on the western majority of the property; however, based on our evaluation the Sant iago Formation appears to be near the surface across most of the property. As encountere d in the borings, Santiago Formation was observed as a dark brown to black clay over sandstone.

4.3 SURFACE WATER AND GROUNDWATER

4.3.1 Surface Water
Surface water was not observed during our visit. If encountered during earthwork construction, surface water is likely the result of precipitation. Overall, area drainage is in a southeast direction.

Provisions for surface drainage will need to be accounted for by the future project civil engineer.

4.3.2 Groundwater
A static groundwater table was not encountered during drilling operations. Excavations B-5 and B-6 appears to have encountered perched water at a depth of approximately 19 and 15 feet (respectively) and cuttings in B-4 at a depth of 17 feet suggest a perch groundwater. Based on the anticipated depth of removals, groundwater is n ot anticipated to be a factor in future development. Localized perched groundwater may be present, but is also not anticipated to be a factor in future development with the exception that seasonal water levels are likely to impact storm water management.

4.4 EARTHQUAKE HAZARDS

4.4.1 Surface Fault Rupture
The geologic structure of the entire southern California area is dominated mainly by northwest- trending faults associated with the San Andreas sys tem. The property is in a seismically active region. No active or potentially active fault is known to exist at this property nor is the property situated within an “Alquist-Priolo” Earthquake Fault Zone or a Special Studies Zone (Br yant and Hart, 2007). No faults transecting the property were identified on the readily available geologic maps reviewed. The nearest known active fault is t he Newport Inglewood-Rose Canyon fault located about 11 miles to the southwest of the property.

4.4.2 Liquefaction/Seismic Settlement
Liquefaction describes a phenomenon in which cyclic stresses, produced by earthquake-induced ground motion, create excess pore pressures in rela tively cohesionless soils. These soils may thereby acquire a high degree of mobility, which ca n lead to lateral movement, sliding, THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 7

consolidation and settlement of loose sediments, sa nd boils and other damaging deformations.

This phenomenon occurs only below the water table, but, after liquefaction has developed, the effects can propagate upward into overlying non-saturated soil as excess pore water dissipates.

The factors known to influence liquefaction potenti al include soil type and grain size, relative density, groundwater level, confining pressures, an d both intensity and duration of ground shaking. In general, materials that are susceptibl e to liquefaction are loose, saturated granular soils having low fines content under low confining pressures.

The liquefaction potential and seismic settlement p otential is considered negligible provided remedial grading recommendations presented herein are completed and due to the general dense to very dense nature of underlying shallow bedrock, as well as planned fill placement.

4.4.3 Other Seismic Hazards
Due to the relatively flat nature of the property, the potential for landslides and rockfall is considered negligible. The potential for secondary seismic hazards such as seiche and tsunami is remote due to property elevation and distance from an open body of water.

5. CONCLUSIONS AND RECOMMENDATIONS

5.1 General
Future development of the property appears feasible from a geotechnical viewpoint provided that the following recommendations are incorporated in t he design and construction phases of the development. The following sections present general recommendations for currently anticipated future development. Due to the preliminary nature of this report, supplemental geotechnical evaluations of the property are anticipated at future dates once more detailed development plans are available. Those supplemental geotechnical recommendations will supersede the preliminary recommendations provided in this report.

5.2 EARTHWORK CONSIDERATIONS

5.2.1 General
Earthwork and grading should be performed in accordance with the applicable grading ordinances of the city of San Marcos, the 2019 (or current) Ca lifornia Building Code (CBC), and recommendations contained in this report. The Grad ing Guidelines included in Appendix C outline general procedures and do not anticipate al l specific situations. In the event of conflict, THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 8

the recommendations presented in the text of this r eport should supersede those contained in Appendix C.

5.2.2 Property Clearing and Preparation
Property preparation should start with removal of d eleterious materials and vegetation. These materials should be disposed of properly off property. Any existing underground improvements, utilities and trench backfill should also be remove d or be further evaluated as part of future development operations.

5.2.3 Remedial Grading
Prior to placement of fill materials and in all str uctural areas the upper variable, potentially compressible materials should be removed. Removals should include all existing fill, colluvium/weathered bedrock materials and we antici pate that the removals will extend approximately 5 feet below existing grade and shoul d also extend to at least 2 feet below the bottom of proposed footings. The lateral extent of removals beyond the outside edge of all settlement sensitive structures/foundations should be equivalent to that vertically removed or five feet, whichever is greater. Depending on actual field conditions encountered during grading, locally deeper and/or shallower areas of removal may be necessary.

In pavement areas, removals should extend at least 2 feet below existing grade or one foot below finished subgrade whichever is lowest.

The bottom of all removals should be scarified to a minimum depth of six (6) inches, brought to slightly above optimum moisture content, and then c ompacted to at least 90% of the soil’s maximum dry density, per ASTM D1557 prior to fill placement. The remedial excavation bottoms should be observed by a GeoTek representative prior to scarification. The resultant voids from remedial grading/overexcavation should be filled with materials placed in general accordance with Section 5.2.4 Engineered Fill of this report.

5.2.4 Engineered Fill
Onsite materials are generally considered suitable for reuse as engineered fill provided they are free from vegetation, roots, debris, and rock/concrete or hard lumps greater than six (6) inches in maximum dimension. The earthwork contractor sho uld have the proposed excavated materials to be used as engineered fill at this pro perty approved by the soils engineer prior to placement.

Engineered fill materials should be moisture condit ioned to at or above optimum moisture content and compacted in horizontal lifts not excee ding 8 inch in loose thickness to a minimum THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 9

relative compaction of 90% as determined in accorda nce with laboratory test procedure ASTM D 1557.

If fill is being placed on slopes steeper than 5:1 (h:v), the fill should be properly benched into the existing slopes and a sufficient size keyway shall be constructed in accordance with grading guidelines presented in Appendix C.

5.2.5 Excavation Characteristics
Excavations can generally be accomplished with heavy-duty earthmoving or excavating equipment in good operating condition. Excavations in sedimentary bedrock may require special excavation equipment and/or techniques.

5.2.6 Shrinkage and Bulking
Several factors will impact earthwork balancing, including bedrock bulking, undocumented fill and colluvium shrinkage, trench spoil from utilities and footing excavations, as well as the accuracy of topography.

Shrinkage and bulking are largely dependent upon the degree of compactive effort achieved during construction. For planning purposes, a shrinkage/bulking factor ranging of plus or minus 5 percent may be considered for surficial undocumented fill m aterials and alluvium. A bulking factor of 5 to 10 percent may be considered for the upper 3 fee t of Santiago Formation bedrock requiring removal and re-compaction. Subsidence should not b e a factor, if removals are completed as recommended.

5.2.7 Trench Excavations and Backfill
Temporary excavations within should be stable at 1: 1 inclinations for short durations during construction, and where cuts do not exceed 10 feet in height. Temporary cuts to a maximum height of 4 feet can be excavated vertically.

Trench excavations should conform to Cal-OSHA regul ations. The contractor should have a competent person, per OSHA requirements, during con struction to observe conditions and to make the appropriate recommendations.

Utility trench backfill should be compacted to at l east 90% relative compaction of the maximum dry density as determined per ASTM D 1557. Under-slab trenches should also be compacted to specifications.

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Onsite materials may not be suitable for use as bedding material, but should be suitable as backfill provided particles larger than 6± inches are removed.

Compaction should be achieved with a mechanical com paction device. Ponding or jetting of trench backfill is not recommended. If backfill so ils have dried out, they should be thoroughly moisture conditioned prior to placement in trenches.

5.3 DESIGN RECOMMENDATIONS

5.3.1 Stormwater Infiltration
Many factors control infiltration of surface waters into the subsurface, such as consistency of native soils and bedrock, geologic structure, fill consistency, material density differences, and existing groundwater conditions. In consideration of the shallow bedrock and anticipated shallow groundwater, infiltration of stormwater into the su bsurface is not recommended from a geotechnical perspective. Stormwater quality contr ol basins should be constructed with an impermeable liner along the sides and bottom.

5.3.2 Foundation Design Criteria
Preliminary foundation design criteria, in general conformance with the 2019 CBC, are presented herein. These are typical design criteria and are n ot intended to supersede the design by the structural engineer. The preliminary recommendatio ns presented below are based on an assumed maximum column load of 150 kips for the pla nned buildings. Once actual structural loads and grading concepts are known, supplemental recommendations may be warranted which may require additional test borings and laboratory testing.

Based on our visual classification of materials enc ountered and as verified by laboratory testing, soils near subgrade are anticipate to exhibit a “me dium” (51 ≤ EI ≤ 90) potential for expansion per ASTM D4829. Materials with “low” (21 ≤ EI ≤ 50 ) expansiveness may also be encountered at depth and could be placed as engineered fill soi ls depending on grading logistics. Additional laboratory testing should be performed at the time of supplemental geotechnical evaluations and upon completion of grading activities to verify the expansion potential and plasticity index of the subgrade soils.

The following criteria for design of foundations are preliminary. Additional laboratory testing of the samples obtained during grading should be perfo rmed and final recommendations should be based on as-graded soil conditions.

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*Code minimums per Table 1809.7 of the 2019 CBC sho uld be complied with. **Effective Plasticity Index should be verified at the completion of the rough grading.

It should be noted that the above recommendations a re based on soil support characteristics only. The structural engineer should design the sl ab and beam reinforcement based on actual loading conditions.

The following recommendations should be implemented into the design:

 Preliminarily, an allowable bearing capacity of 2,500 pounds per square foot (psf) may be considered for design of continuous and perimete r footings that meet the depth and width requirements in the table above. This va lue may be increased by 400 psf for each additional 12 inches in depth and 100 psf for each additional 12 inches in width to a maximum value of 3,000 psf. Additionally, an increase of one-third may be applied when considering short-term live loads (e.g . seismic and wind loads). It may be possible to utilize a higher allowable soil bearing pressure for foundations directly supported by bedrock. The determination of an allo wable soil bearing pressure on bedrock should be determined once foundation loads and elevations are known.

 Based on our experience in the area, structural fou ndations may be designed in accordance with 2019 CBC, and to withstand a total settlement of 1 inch and maximum differential settlement of one-half of the total settlement over a horizontal distance of 30 feet. Seismically induced settlement is considered to be minimal.

DESIGN PARAMETES FOR CONVENTIONALL REINFORCED SHALLOW

FOUNDATIONS
Design Parameter “Low”
Expansion Potential (21 ≤EI≤50)
“Medium”
Expansion Potential (51 ≤EI≤90)
Foundation Embedment Depth or
Minimum Perimeter Beam Depth
(inches below lowest adjacent
finished grade)
One- and Two Story – 12
Three and Four-Story-24
One- and Two Story – 18
Three and Four-Story- 24
Minimum Foundation Width
(Inches)*
One - and Two Story – 12
Three and Four Story - 18
One - and Two Story – 12
Three and Four Story - 18
Minimum Slab Thickness (actual) 4 inches 4 inches
Minimum Slab Reinforcing
No. 3 rebar 24” on -center,
each way, placed in the middle
one -third of the slab thickness
No. 3 rebar 18” on -center,
each way, placed in the middle
one -third of the slab thickness
Minimum Footing Reinforcement Two No. 4 reinforcing bars, one top and one bottom
Four No. 4 reinforcing bars,
two top and two bottom
Effective Plasticity Index** <15 20
Presaturation of Subgrade Soil
(percent of optimum moisture
content)
Minimum 110% to a depth of
12 inches
Minimum 120% to a depth of
18 inches
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 The passive earth pressure may preliminarily be computed as an equivalent fluid having a density of 220 psf per foot of depth, to a maximu m earth pressure of 2,500 psf for footings founded on engineered fill. A coefficient of friction between soil and concrete of 0.35 may be used with dead load forces. When com bining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third.

 A grade beam, a minimum of 12 inches wide and 12 in ches deep, should be utilized across large entrances, however, the base of the gr ade beam should be at the same elevation as the bottom of the adjoining footings.

 We recommend that control joints be placed in two di rections spaced the numeric equivalent roughly 24 times the thickness of the slab in inches (e.g. a 4 inch slab would have control joints at 96 inch [8 feet] centers). These joints are a widely accepted means to control cracks and should be reviewed by the structural engineer.

5.3.3 Underslab Moisture Membrane
A moisture and vapor retarding system should be pla ced below slabs-on-grade where moisture migration through the slab is undesirable. Guidelines for these are provided in the 2019 California Green Building Standards Code (CALGreen) Section 4.505.2 and the 2019 CBC Section 1907.1

It should be realized that the effectiveness of the vapor retarding membrane can be adversely impacted as a result of construction related punctu res (e.g. stake penetrations, tears, punctures from walking on the vapor retarder placed atop the underlying aggregate layer, etc.). These occurrences should be limited as much as possible during construction. Thicker membranes are generally more resistant to accidental puncture that thinner ones. Products specifically designed for use as moisture/vapor retarders may also be mor e puncture resistant. Although the CBC specifies a 6 mil vapor retarder membrane, it is Ge oTek’s opinion that a minimum 10 mil membrane with joints properly overlapped and sealed should be considered, unless otherwise specified by the slab design professional.

Moisture and vapor retarding systems are intended t o provide a certain level of resistance to vapor and moisture transmission through the concret e, but do not eliminate it. The acceptable level of moisture transmission through the slab is to a large extent based on the type of flooring used and environmental conditions. Ultimately, the vapor retarding system should be comprised of suitable elements to limit migration of water and reduce transmission of water vapor through the slab to acceptable levels. The selected elemen ts should have suitable properties (i.e. thickness, composition, strength and permeability) to achieve the desired performance level.

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Moisture retarders can reduce, but not eliminate, m oisture vapor rise from the underlying soils up through the slab. Moisture retarder systems sho uld be designed and constructed in accordance with applicable American Concrete Instit ute, Portland Cement Association, Post- Tensioning Concrete Institute, ASTM and California Building Code requirements and guidelines.

GeoTek does not practice in the field of moisture vapor transmission evaluation/migration, since that practice is not a geotechnical discipline. Therefore, we recommend that a qualified person, such as the flooring contractor, structural enginee r, architect, and/or other experts specializing in moisture control within the building be consulted to evaluate the general and specific moisture and vapor transmission paths and associated potential impact on the proposed construction. That person (or persons) should provide recommendations relative to the slab moisture and vapor retarder systems and for migration of potential adv erse impact of moisture vapor transmission on various components of the structures, as deemed appropriate. In addition, the recommendations in this report and our services in general are not intended to address mold prevention; since we, along with geotechnical consu ltants in general, do not practice in the area of mold prevention. If specific recommendations ad dressing potential mold issues are desired, then a professional mold prevention consultant should be contacted.

5.3.4 Miscellaneous Foundation Recommendations

 To reduce moisture penetration beneath the slab on grade areas, utility trenches should be backfilled with engineered fill, lean concrete or concrete slurry where they intercept the perimeter footing or thickened slab edge.

 Spoils from the footing excavations should not be p laced in the slab-on-grade areas unless properly compacted and tested. The excavati ons should be free of loose/sloughed materials and be neatly trimmed at the time of concrete placement.

5.3.5 Foundation Set Backs
Where applicable, the following setbacks should apply to all foundations. Any improvements not conforming to these setbacks may be subject to late ral movements and/or differential settlements:

 The outside bottom edge of all footings should be set back a minimum of H/3 (where H is the slope height) from the face of any descend ing slope. The setback should be at least 7 feet and need not exceed 40 feet.

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 The bottom of all footings for structures near retaining walls should be deepened so as to extend below a 1:1 projection upward from the bottom inside edge of the wall stem. This applies to the existing retaining walls along the perimeter, if they are to remain.

 The bottom of any existing foundations for structur es should be deepened so as to extend below a 1:1 projection upward from the bottom of the nearest excavation.

5.3.6 Seismic Design Parameters
The property is located at approximately 33.1394 La titude and -117.1961 Longitude. Spectral accelerations (Ss and S1), for 0.2 and 1.0 second p eriods for a risk targeted two (2) percent probability of exceedance in 50 years (MCER) were determined using the web interface provided by SEAOC/OSHPD ( https://seismicmaps.org ) to access the USGS Seismic Design Parameters.

We have selected a Site Class “C” based on the apparent density of the old alluvial deposits. The results, based on ASCE 7-16 and the 2019 CBC, are presented in the following table.

SEISMIC PARAMETERS
Mapped 0.2 sec Period Spectral Acceleration, S s 0.897 g Mapped 1.0 sec Period Spectral Acceleration, S 1 0. 331 g Coefficient for Site Class “ C”, F a 1. 2
Coefficient for Site Class “ C”, F v 1. 5
Maximum Considered Earthquake ( MCE R) Spectral
Response Acceleration for 0.2 Second , S MS 1.077g
Maximum Considered Earthquake ( MCE R) Spectral
Response Acceleration for 1.0 Second, S M1 0.496g
5% Damped Design Spectral Response
Acceleration Parameter at 0.2 Second, S DS 0.718g
5% Damped Design Spectral Response
Acceleration Parameter at 1 second, S D1 0.331g
Modified Peak Ground Acceleration (PGA M) 0.465g
Seismic Design Category D

5.3.7 Soil Sulfate Content
Nearby sulfate content test results indicate water soluble sulfate is less than 0.1 percent by weight, which is considered “S0” as per Table 19.3. 1.1 of ACI 318-14, as such no special recommendations for concrete are included herein.

5.3.8 Preliminary Pavement Design
Traffic indices have not been provided to our firm during this stage of planning. In addition, remedial graded has not been completed to evaluate specific street subgrade conditions.

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Therefore, we have referenced the minimum structural sections based on the City of San Marcos’ Urban Street Design for residential streets (San Marcos, 2020) and are presented below.

PRELIMINARY ASPHALT PAVEMENT STRUCTURAL

SECTION
Design Criteria + Asphaltic Concrete (AC)
Thickness (inches)
Aggregate Base (AB)
Thickness (inches)
Residential 3.0 6.0

As noted in the Urban Street Design document, actua l structural pavement design is to be determined by the geotechnical engineer’s testing (R-value) of the subgrade. Thus, the actual R- value of subgrade soils can only be determined at t he completion of grading for street subgrade and the above values are subject to change based la boratory testing of the as-graded soils near subgrade elevations. The final pavement design may be thicker than the City of San Marcos minimum thickness presented above.

Asphalt concrete and aggregate base should conform to current Caltrans Standard Specifications Section 39 and 26-1.02, respectively. As an alternative, asphalt concrete can conform to Section 203-6 of the current Standard Specifications for Public Work (Green Book). Crushed aggregate base or crushed miscellaneous base can conform to S ection 200-2.2 and 200-2.4 of the Green Book, respectively. Pavement base should be compac ted to at least 95 percent of the ASTM D1557 laboratory maximum dry density (modified proctor).

All pavement installation, including preparation and compaction of subgrade, compaction of base material, placement and rolling of asphaltic concrete, should be done in accordance with the city of San Marcos specifications, and under the observa tion and testing of GeoTek and a City Inspector where required. Jurisdictional minimum c ompaction requirements in excess of the aforementioned minimums may govern.

5.4 RETAINING WALL DESIGN AND CONSTRUCTION

5.4.1 General Design Criteria
Preliminary plans are not yet available, if retaini ng walls are added at a later date, the recommendations presented herein may apply to typic al masonry or concrete vertical retaining walls to a maximum height of 10 feet. Additional r eview and recommendations should be requested for higher walls.

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Retaining wall foundations embedded a minimum of 18 inches into engineered fill or dense formational materials should be designed using an a llowable bearing capacity of 2500 psf. An increase of one-third may be applied when consideri ng short-term live loads (e.g. seismic and wind loads). The passive earth pressure may be computed as an equivalent fluid having a density of 220 psf per foot of depth, to a maximum earth pressure of 3,000 psf. A coefficient of friction between soil and concrete of 0.35 may be used with dead load forces. When combining passive pressure and frictional resistance, the passive pre ssure component should be reduced by one- third.

An equivalent fluid pressure approach may be used t o compute the horizontal active pressure against the wall. The appropriate fluid unit weights are given in the table below for specific slope gradients of retained materials.

Surface Slope of
Retained Materials
(H:V)
Equivalent Fluid Pressure
(PCF)
Select Backfill*
Level 35
2:1 55
*Select backfill should consist of native or import ed sand other approved materials with an SE>30 and an EI<20 and s hould be provided throughout the active zone.

The above equivalent fluid weights do not include o ther superimposed loading conditions such as expansive soil, vehicular traffic, structures, seismic conditions or adverse geologic conditions.

Additional lateral forces can be induced on retaining walls during an earthquake. For level backfill and a Site Class “C”, a supplemental earthquake-ind uced equivalent fluid pressure of 14.4 pcf should be considered, where required. This force c an be assumed to act as a typical fluid pressure, resulting in a triangular pressure distri bution. The 2019 CBC only requires the additional earthquake induced lateral force be cons idered on retaining walls in excess of six (6) feet in height; however, the additional force may b e applied in design of lesser walls at the discretion of the wall designer.

5.4.2 Restrained Retaining Walls
Any retaining wall that will be restrained prior to placing backfill or walls that have male or reentrant corners should be designed for at-rest soil conditions using an equivalent fluid pressure of 60 pcf (select backfill), plus any applicable surcharge loading. For areas having male or reentrant corners, the restrained wall design should extend a minimum distance equal to twice the height of the wall laterally from the corner, or as otherwise determined by the structural engineer.

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5.4.3 Wall Backfill and Drainage
Wall backfill should include a minimum one (1) foot wide section of ¾ to 1-inch clean crushed rock (or approved equivalent). The rock should be placed immediately adjacent to the back of wall and extend up from the backdrain to within app roximately 12 inches of finish grade. The upper 12 inches should consist of compacted onsite materials. If the walls are designed using the “select” backfill design parameters, then the “sele ct” materials shall be placed within the active zone as defined by a 1:1 (H:V) projection from the back of the retaining wall footing up to the retained surface behind the wall. Presence of othe r materials might necessitate revision to the parameters provided and modification of wall designs.

The backfill materials should be placed in lifts no greater than 8-inches in thickness and compacted to a minimum of 90% of the maximum dry density as determined in accordance with ASTM Test Method D 1557. Proper surface drainage needs to be provided and maintained. Water should not be allowed to pond behind retaining walls. Wate rproofing of walls should be performed where moisture migration through the wall is undesirable.

Retaining walls should be provided with an adequate pipe and gravel back drain system to reduce the potential for hydrostatic pressures to develop. A 4-inch diameter perforated collector pipe (Schedule 40 PVC, or approved equivalent) in a minimum of one (1) cubic foot per lineal foot of 3/8 to one (1) inch clean crushed rock or equivalen t, wrapped in filter fabric should be placed near the bottom of the backfill and be directed (via a solid outlet pipe) to an appropriate disposal area.

Drain outlets should be maintained over the life of the future proejct and should not be obstructed or plugged by adjacent improvements.

5.5 POST CONSTRUCTION CONSIDERATIONS

5.5.1 Landscape Maintenance and Planting
Water has been shown to weaken the inherent strength of soil, and slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from graded slopes should be maintained and only the amount of irrigation necess ary to sustain plant life should be provided for planted slopes. Controlling surface drainage and runoff and maintaining a suitable vegetation cover can minimize erosion. Plants selected for la ndscaping should be lightweight, deep-rooted types that require little water and are capable of surviving the prevailing climate.

Overwatering should be avoided. The soils should be maintained in a solid to semi-solid state as defined by the materials Atterberg Limits. Care sh ould be taken when adding soil amendments THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 18

to avoid excessive watering. Leaching as a method of soil preparation prior to planting is not recommended. An abatement program to control groun d-burrowing rodents should be implemented and maintained. This is critical as burrowing rodents can decreased the long-term performance of slopes.

It is common for planting to be placed adjacent to structures in planter or lawn areas. This will result in the introduction of water into the ground adjacent to the foundation. This type of landscaping should be avoided. If used, then extre me care should be exercised with regard to the irrigation and drainage in these areas. Waterproofing of the foundation and/or subdrains may be warranted and advisable. We could discuss these issues, if desired, when plans are made available.

5.5.2 Drainage
The need to maintain proper surface drainage and subsurface systems cannot be overly emphasized.

Positive drainage should be maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and not allowed to pond or seep into the ground adjacent to the footings. Property drainage should conform to Section 1804.4 of the 2019 CBC. Roof gutters and downspouts should discharge onto paved surfaces sloping away from the structure or into a closed pipe syste m which outfalls to the street gutter pan or directly to the storm drain system. Pad drainage should be directed toward approved areas and not be blocked by other improvements.

5.6 PLAN REVIEW AND CONSTRUCTION OBSERVATIONS
We recommend that future grading, specifications, re taining wall/shoring plans and foundation plans be reviewed by this office prior to construct ion to check for conformance with the recommendations of this report. Additional recommendations may be necessary based on these reviews. We also recommend that GeoTek representatives be present during future grading and foundation construction to check for proper impleme ntation of the geotechnical recommendations. The owner/developer should have GeoTek’s representative perform at least the following duties:
 Observe clearing and grubbing operations for proper removal of unsuitable materials.  Observe and test bottom of removals prior to fill placement.  Evaluate the suitability of on-site and import mate rials for fill placement, and collect soil samples for laboratory testing when necessary.
 Observe the fill for uniformity during placement including utility trenches.  Observe and test the fill for field density and relative compaction.  Observe and probe foundation excavations to confirm suitability of bearing materials.

THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 19

If requested, a construction observation and compac tion report can be provided by GeoTek, which can comply with the requirements of the gover nmental agencies having jurisdiction over the future development. We recommend that these agencies be notified prior to commencement of construction so that necessary grading permits can be obtained.

6. LIMITATIONS
The scope of our evaluation is limited to the area explored that is shown on the Boring Location Map (Figure 2). This evaluation does not and shoul d in no way be construed to encompass any areas beyond the specific area of proposed construc tion as indicated to us by the client. The scope is based on our understanding of the future d evelopment and the client’s needs, our proposal (Proposal No. P-0300620-SD) dated March 25 , 2020 and geotechnical engineering standards normally used on similar property in this region.

The materials observed on the property appear to be representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during property construction. Property con ditions may vary due to seasonal changes or other factors. GeoTek, Inc. assumes no responsi bility or liability for work, testing or recommendations performed or provided by others.

Since our recommendations are based on the property conditions observed and encountered, and laboratory testing, our conclusions and recommendations are professional opinions that are limited to the extent of the available data. Obser vations during construction are important to allow for any change in recommendations found to be warranted. These opinions have been derived in accordance with current standards of practice and no warranty is expressed or implied.

Standards of practice are subject to change with time.

THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page 20

7. SELECTED REFERENCES
American Society of Civil Engineers (ASCE), 2016, “ Minimum Design Loads for Buildings and Other Structures,” ASCE/SEI 7-16.

ASTM International (ASTM), “ASTM Volumes 4.08 and 4.09 Soil and Rock.” Bryant, W.A., and Hart, E.W., 2007, "Fault Rupture Ha zard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquak e Fault Zones Maps," California Geological Survey: Special Publication 42.

California Code of Regulations, Title 24, 2019 “California Building Code,” 3 volumes.

California Geological Survey (CGS, formerly referred to as the California Division of Mines and Geology), 1977, “Geologic Map of California.”
____, 1998, “Maps of Known Active Fault Near-Source Zones in California and Adjacent Portions of Nevada,” International Conference of Building Officials.

City of San Marcos, 2012, City of San Marcos General Plan, adopted February 14, 2012. ____, 2016, “City of San Marcos BMP Design Manual,” dated February 2016. ____, 2020, “City of San Marcos Urban Street Design Criteria,” https://www.san- marcos.net/home/showdocument?id=11091 not dated, accessed October 27, 2020.

GeoTek, Inc., In-house proprietary information.

Kennedy, M.P., and Tan, S.S., 2007, “Geologic Map of the Oceanside 30x60-minute Quadrangle, California,” California Geological Survey, Regional Geologic Map No. 2, map scale 1:100,000.

Structural Engineers Association of California/California Office of Statewide Health Planning and Development (SEOC/OSHPD), 2019, Seismic Design Maps web interface, https://seismicmaps.org
Terzaghi, K. and Peck, R., 1967, “Soil Mechanics in Engineering Practice”, second edition. 1384 Poinsettia Avenue, Suite A
Vista, California 92081-8505
Figure 1
Site Location Map
Pacific GPA/Rezone Project
NW Corner of Linda Vista & Las Posas Rd.

San Marcos, California
PN: 3649-SD October 2021
Interactive Visitor Map from US Forestry Service, 2021

NOT TO SCALE

APPROXIMATE

SITE LOCATION
LEGEND

APPROXIMATE LOCATION OF ALLUVIUM

BORING TEST LOCATIONS
LIMITS OF PROPERTY SANTIAGO FORMATION, CIRCLED WHERE BURIED 1384 Poinsettia Avenue, Suite A Vista, California 92081
The Los Posas Owner LPV, LLC
Pacific GPA/Rezone
NW Corner of Linda Vista Dr. & Las Posas
San Marcos, California
PN: 3649-SD October 2021
Figure 2
Boring Location
Plan
Tsa
Qal
Tsa
Qal
Tsa
P-2
B-6P-1
B-5
B-4
B-3
B-6

APPENDIX A

EXPLORATORY BORING LOGS
AND

INFILTRATION WORKSHEETS

THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page A-1

A - FIELD TESTING AND SAMPLING PROCEDURES

The Modified Split-Barrel Sampler (Ring)
The Ring sampler is driven into the ground in accordance with ASTM Test Method D 3550. The sampler, with an external diameter of 3.0 inches, is lined with 1-inch long, thin brass rings with inside diameters of approximately 2.4 inches. The sampler is typically driven into the ground 12 or 18 inches with a 140- pound hammer free falling from a height of 30 inche s. Blow counts are recorded for every 6 inches of penetration as indicated on the log of boring. The samples are removed from the sample barrel in the brass rings, sealed, and transported to the laboratory for testing.

Bulk Samples (Large)
These samples are normally large bags of earth mate rials over 20 pounds in weight collected from the field by means of hand digging or exploratory cuttings.

Bulk Samples (Small)
These are plastic bag samples which are normally ai rtight and contain less than 5 pounds in weight of earth materials collected from the field by means of hand digging or exploratory cuttings. These samples are primarily used for determining natural moisture content and classification indices.

B –EXCAVATION LOG LEGEND
The following abbreviations and symbols often appear in the classification and description of soil and rock on the logs of borings and trenches:

SOILS
USCS Unified Soil Classification System
f-c Fine to coarse
f-m Fine to medium

GEOLOGIC
B: Attitudes Bedding: strike/dip
J: Attitudes Joint: strike/dip
C: Contact line
……….. Dashed line denotes USCS material change
Solid Line denotes unit / formational change
Thick solid line denotes end of boring
(Additional denotations and symbols are provided on the logs) GeoTek, Inc.

LOG OF EXPLORATORY BORING
BB-1
13 R-1 9.4 121.9
22 74
10 S-1
21 21
11 R-2 11.4 124.3
50/6"
12 S-2
20 24
---Small Bulk ---No Recovery ---W ater Table PROJECT NAME: Pacific San Marcos DRILL METHOD: CME-75 HAS OPERATOR:

CLIENT: The Las Posas Owner LPV, LLC DRILLER: Baja Exploration LOGGED BY: CDL LOCATION: See Boring Locaiton Map ELEVATION: DATE: 9/29/2020 PROJECT NO.: 3649-SD HAMMER: 140lbs/30in RIG TYPE: CME-75 Dry Density
(pcf)
Others

MATERIAL DESCRIPTION AND COMMENTS
Dirt Road

SAMPLES
USCS Symbol
BORING NO.: B-3
Laboratory Testing
Depth (ft)
Sample Type
Blows/ 6 in
Sample
Number
Water Content
(%)

Tertiary Santiago Formation
Clayey medium SANDSTONE, pale yellow, moist, very dense, transition in 5 sample
Weathered Santiago/Colluvium
CLAY, dark brown-black, dry, trace sand

10 Clayey medium SANDSTONE, pale yellow, moist, very dense Clayey fine SANDSTONE, orange brown and play yellow, moist, very dense, light olive gray claystone in shoe, moist, hard, bedded oxidation 15 Clayey medium SANDSTONE, pale yellow, moist, very dense Backfilled with soil cuttings

20 HOLE TERMINATED AT 19.5 FEET
No groundwater encountered
25 AL = Atterberg Limits EI = Expansion Index SA = Si eve Analysis RV = R-Value Test SR = Sulfate/Resisitivity Test SH = Shear Test CO = Consolidation test MD = Maximum Density 30 LEGEND
Sample type : ---Ring ---SPT ---Large Bulk Lab testing:

GeoTek, Inc.

LOG OF EXPLORATORY BORING
BB-1
15 14 R-1 8.9 124.2
18 12 S-1
21 34
13 R-2 12.5 119.1
50/6"
12 26
33 ---Small Bulk ---No Recovery ---W ater Table PROJECT NAME: Pacific San Marcos DRILL METHOD: 8" HSA 3.75" ID OPERATOR:

CLIENT: The Las Posas Owner LPV, LLC DRILLER: Baja Exploration LOGGED BY: CDL LOCATION: See Boring Locaiton Map ELEVATION: DATE: 9/29/2020 PROJECT NO.: 3649-SD HAMMER: 140lbs/30in RIG TYPE: CME-75 Dry Density
(pcf)
Others

MATERIAL DESCRIPTION AND COMMENTS
Vegatation over

SAMPLES
USCS Symbol
BORING NO.: B-4
Laboratory Testing
Depth (ft)
Sample Type
Blows/ 6 in
Sample
Number
Water Content
(%)
5 Tertiary Santiago Formation
Weathered Santiago/Colluvium
Silty fine SAND, light brown, dry, loose

10 Clayey medium SANDSTONE, light gray, very moist, very dense, ~15% fine Clayed medium SANDSTONE, pale yellow white, very mosit, medium dense, mottled orange oxidation

15 Clayey medium SAND, light gray, very moist, very dense, ~15% fine

Cuttings are very wet, dark orange brown, 30-40% fine
Clayey fine SANDSTONE, mottled orange, brown and pale white, very moist, very dense
Backfilled with soil cuttings

20 HOLE TERMINATED AT 19.5 FEET
Some groundwater encountered at 17 feet
25 AL = Atterberg Limits EI = Expansion Index SA = Si eve Analysis RV = R-Value Test SR = Sulfate/Resisitivity Test SH = Shear Test CO = Consolidation test MD = Maximum Density 30 LEGEND
Sample type : ---Ring ---SPT ---Large Bulk Lab testing:

GeoTek, Inc.

LOG OF EXPLORATORY BORING
BB-1
12 R-1 7.8 129.4
27 54
S-1
10 R-2 11.6 109.6
17 25
19 S-2
27 41
---Small Bulk ---No Recovery ---W ater Table PROJECT NAME: Pacific San Marcos DRILL METHOD: 8" HSA 3.75" ID OPERATOR:

CLIENT: The Las Posas Owner LPV, LLC DRILLER: Baja Exploration LOGGED BY: BRM LOCATION: See Boring Locaiton Map ELEVATION: DATE: 9/29/2020 PROJECT NO.: 3649-SD HAMMER: 140lbs/30in RIG TYPE: CME 75 Dry Density
(pcf)
Others

MATERIAL DESCRIPTION AND COMMENTS
Dirt Road Patch, Slight Vegatation

SAMPLES
USCS Symbol
BORING NO.: B-5
Laboratory Testing
Depth (ft)
Sample Type
Blows/ 6 in
Sample
Number
Water Content
(%)
5 Clayey SANDSTONE, tan-yellow, moist
Tertiary Santiago Formation
Clayey SAND
10 Silty fine SANDSTONE, oxidation layers tan, damp

15 Silty fine SANDSTONE, orange brown, moist, very dense

CLAYSTONE, dark brown, moist, very stiff, fne cut sandy sandstone, dark brown, moist
Silty medium-coarse SANDSTONE, light gray, wet, very dense Backfilled with soil cuttings

20 HOLE TERMINATED AT 19.5 FEET
Groundwater encountered at 18 feet
25 AL = Atterberg Limits EI = Expansion Index SA = Si eve Analysis RV = R-Value Test SR = Sulfate/Resisitivity Test SH = Shear Test CO = Consolidation test MD = Maximum Density 30 LEGEND
Sample type : ---Ring ---SPT ---Large Bulk Lab testing:

GeoTek, Inc.

LOG OF EXPLORATORY BORING
16 R-1 8 120.6
26 40
4 S-2
7 12
11 R-2 10.7 128.8
27 28
7 S-2
14 29
---Small Bulk ---No Recovery ---W ater Table PROJECT NAME: Pacific San Marcos DRILL METHOD: 8" HSA 3.75" ID OPERATOR:

CLIENT: The Las Posas Owner LPV, LLC DRILLER: Baja Exploration LOGGED BY: CDL LOCATION: See Boring Locaiton Map ELEVATION: DATE: 9/29/2020 PROJECT NO.: 3649-SD HAMMER: 140lbs/30in RIG TYPE: CME-75 Dry Density
(pcf)
Others

MATERIAL DESCRIPTION AND COMMENTS
Grassland Over

SAMPLES
USCS Symbol
BORING NO.: B-6
Laboratory Testing
Depth (ft)
Sample Type
Blows/ 6 in
Sample
Number
Water Content
(%)
Tertiary Santiago Formation
5 Silty coarse SANDSTONE, interbedded light gray and orange brown, moist, Alluvium (Qal)
Silty fine SAND, light brown, dry, loose

10 CLAYSTONE, medium gray, fractured, well healed with orange oxidized fine very dense, ~15% fines

15 Medium-coarse SANDSTONE, richly oxidized orange brown, wet, very dense, sand

laminiated silty and clayey sandstone, ~20% fine, moist CLAYSTONE, dark gray, moist, hard
Perched groundwater encountered at 15 feet
Backfilled with soil cuttings

Slity fine SANDSTONE, dark gray, moist, 40% fine, decomposed organic 20 matter
HOLE TERMINATED AT 19.5 FEET
25 AL = Atterberg Limits EI = Expansion Index SA = Si eve Analysis RV = R-Value Test SR = Sulfate/Resisitivity Test SH = Shear Test CO = Consolidation test MD = Maximum Density 30 LEGEND
Sample type : ---Ring ---SPT ---Large Bulk Lab testing:

Job No.: 3649-SD .

Date: 9/30/20 .

After Test: .

Reading
No. Time
Time
Interval
(Min)
Total
Depth of
Hole
(Inches)
Initial
Water
Level
(Inches)
Final
Water
Level
(Inches)

∆ In Water
Level
(Inches)
Rate
(minutes
per inch)
Comments
1 8:56 30 35.75 10.5 11.75 1.25 0.03
2 9:26 30 35.75 9.75 10.5 0.75 0.02
3 9:56 30 35.75 8.75 9.5 0.75 0.02
4 10:26 30 35.75 8.75 9.5 0.75 0.02
5 10:56 30 35.75 8.25 9 0.75 0.02
6 11:26 30 35.75 8.25 9 0.75 0.02
7 11:56 30 35.75 7.5 8.25 0.75 0.02
8 12:26 30 35.75 7.5 8.25 0.75 0.02
9 12:56 30 35.75 6.5 7.25 0.75 0.02
10 13:26 30 35.75 5.75 6.75 1 0.03
11 13:56 30 35.75 6 7 1 0.03
12 14:26 30 35.75 6.75 7.25 0.5 0.01
13 14
15 16

PERCOLATION DATA SHEET
Project: Pacific San Marcos
Test Hole No.: PB-1 Tested By: MRB , Depth of Hole As Drilled: 35.75" Before Test: _________________________ minutes
inches
inches
inches
inches
Equation - It =
inches
inches
inches
Havg = (HO+HF)/2 = inches
It = Inches per Hour0.07
Total Test Hole Depth, DT = 35.75
ΔH (60r)
Δt (r+2Havg)
HO = DT - DO = 29.00
HF = DT - DF = 28.50
ΔH = ΔD = HO- HF = 0.50

28.75 Final Depth to Water, DF = 7.25
Test Hole Radius, r = 4.00
Initial Depth to Water, D
O = 6.75
Time Interval, Δt = 30
Client: The Las Posas Owner LPV, LLC
Project: Pacific
Project No: 3649-SD
Date: 9/30/2020
Boring No. P-1
Infiltration Rate (Porchet Method)

Job No.: 3649-SD .

Date: 9/30/20 .

After Test: .

Reading
No. Time
Time
Interval
(Min)
Total
Depth of
Hole
(Inches)
Initial
Water
Level
(Inches)
Final
Water
Level
(Inches)

∆ In Water
Level
(Inches)
Rate
(minutes
per inch)
Comments
1 8:59 30 34.75 10.25 10.9 0.65 0.02
2 9:29 30 34.75 9 9.25 0.25 0.01
3 9:59 30 34.75 8.5 8.75 0.25 0.01
4 10:29 30 34.75 7.75 8.5 0.75 0.02
5 10:59 30 34.75 7 7.75 0.75 0.02
6 11:29 30 34.75 7 7.75 0.75 0.02
7 11:59 30 34.75 6.5 7.25 0.75 0.02
8 12:29 30 34.75 6.5 7.25 0.75 0.02
9 12:59 30 34.75 6.5 7 0.5 0.01
10 13:29 30 34.75 6.75 7.25 0.5 0.01
11 13:59 30 34.75 6.5 7 0.5 0.01
12 14:29 30 34.75 6.75 7.25 0.5 0.01
13 14

PERCOLATION DATA SHEET
Project: Pacific San Marcos
Test Hole No.: PB-2 Tested By: MRB , Depth of Hole As Drilled: 34.75 Before Test: ________________________ minutes
inches
inches
inches
inches
Equation - It =
inches
inches
inches
Havg = (HO+HF)/2 = inches
It = Inches per Hour0.07
Total Test Hole Depth, DT = 34.75
ΔH (60r)
Δt (r+2Havg)
HO = DT - DO = 28.00
HF = DT - DF = 27.50
ΔH = ΔD = HO- HF = 0.50

27.75 Final Depth to Water, DF = 7.25
Test Hole Radius, r = 4.00
Initial Depth to Water, D
O = 6.75
Time Interval, Δt = 30
Client: The Las Posas Owner LPV, LLC
Project: Pacific
Project No: 3649-SD
Date: 9/30/2020
Boring No. P-2
Infiltration Rate (Porchet Method)

APPENDIX B

RESULTS OF LABORATORY TESTING

THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Revised Preliminary Geotechnical Evaluation January 4, 2022 Pacific GPA/Rezone, San Marcos, California Page B-1

SUMMARY OF LABORATORY TESTING

Identification and Classification

Soils were identified visually in general accordanc e to the standard practice for description and identification of soils (ASTM D2488). The soil identifications and classifications are shown on the logs of exploratory borings in Appendix A.

Expansion Index
Expansion Index testing was performed on one soil sample. Testing was performed in general accordance with ASTM Test Method D 4829. The results of the testing are provided below.

Boring No. Depth
(ft.) Soil Type Expansion Index Classification
B-3 0-5 Dark Brown Black
Clay 81 Medium

Moisture-Density Relationship
Laboratory testing was performed on one sample coll ected during the subsurface exploration. The laboratory maximum dry density and optimum moisture content for the soil type was determined in general accordance with test method ASTM Test Proce dure D1557. The results of the testing are provided below.

Boring No. Depth
(ft.) Description Maximum Dry
Density (pcf)
Optimum
Moisture Content
(%)
B-3 0-5 Dark Brown Black Clay 114.5 15.0

APPENDIX C

GENERAL EARTHWORK GRADING GUIDELINES

GENERAL GRADING GUIDELINES APPENDIX C

GENERAL GRADING GUIDELINES
Guidelines presented herein are intended to address general construction procedures for earthwork construction. Specific situations and conditions o ften arise which cannot reasonably be discussed in general guidelines, when anticipated these are disc ussed in the text of the report. Often unanticipat ed conditions are encountered which may necessitate modification or changes to these guidelines. It is our hope that these will assist the contractor to more efficiently complete the project by providing a reasonable understanding of the procedures that wou ld be expected during earthwork and the testing and observation used to evaluate those procedures.

General
Grading should be performed to at least the minimum requirements of governing agencies, Chapters 18 and 33 of the California Building Code, CBC (2019) and the guidelines presented below.

Preconstruction Meeting
A preconstruction meeting should be held prior to s ite earthwork. Any questions the contractor has regarding our recommendations, general site conditi ons, apparent discrepancies between reported and actual conditions and/or differences in procedures the contractor intends to use should be brought up at that meeting. The contractor (including the mai n onsite representative) should review our report and these guidelines in advance of the meeting. Any comments the contractor may have regarding these guidelines should be brought up at that meeting.

Grading Observation and Testing

1. Observation of the fill placement should be provide d by our representative during grading.

Verbal communication during the course of each day will be used to inform the contractor of test results. The contractor should receive a copy of the "Daily Field Report" indicating results of field density tests that day. If our representa tive does not provide the contractor with these reports, our office should be notified.

2. Testing and observation procedures are, by their na ture, specific to the work or area observed and location of the tests taken, variability may oc cur in other locations. The contractor is responsible for the uniformity of the grading opera tions; our observations and test results are intended to evaluate the contractor’s overall level of efforts during grading. The contractor’s personnel are the only individuals participating in all aspect of site work. Compaction testing and observation should not be considered as relieving the contractor’s responsibility to properly compact the fill.

3. Cleanouts, processed ground to receive fill, key ex cavations, and subdrains should be observed by our representative prior to placing any fill. I t will be the contractor's responsibility to notify our representative or office when such areas are ready for observation.

4. Density tests may be made on the surface material t o receive fill, as considered warranted by this firm.

5. In general, density tests would be made at maximum intervals of two feet of fill height or every 1,000 cubic yards of fill placed. Criteria will vary depending on soil conditions and size of the fill.

More frequent testing may be performed. In any case, an adequate number of field density tests should be made to evaluate the required compaction and moisture content is generally being obtained.

GENERAL GRADING GUIDELINES APPENDIX C

6. Laboratory testing to support field test procedures will be performed, as considered warranted, based on conditions encountered (e.g. change of mat erial sources, types, etc.) Every effort will be made to process samples in the laboratory as quickly as possible and in progress construction projects are our first priority. However, laborato ry workloads may cause in delays and some soils may require a minimum of 48 to 72 hours to complete test procedur es .

Whenever possible, our representative(s) should be informed in advance of operational changes that might result in different source areas for materials.

7. Procedures for testing of fill slopes are as follows:
a) Density tests should be taken periodically during g rading on the flat surface of the fill, three to five feet horizontally from the face of the slope. b) If a method other than over building and cutting ba ck to the compacted core is to be employed, slope compaction testing during construction should include testing the outer six inches to three feet in the slope face to deter mine if the required compaction is being achieved.

8. Finish grade testing of slopes and pad surfaces sho uld be performed after construction is complete.

Site Clearing

1. All vegetation, and other deleterious materials, sh ould be removed from the site. If material is not immediately removed from the site it should be stockpiled in a designated area(s) well outside of all current work areas and delineated wi th flagging or other means. Site clearing should be performed in advance of any grading in a specific area.

2. Efforts should be made by the contractor to remove all organic or other deleterious material from the fill, as even the most diligent efforts ma y result in the incorporation of some materials.

This is especially important when grading is occurr ing near the natural grade. All equipment operators should be aware of these efforts. Laborers may be required as root pickers.

3. Nonorganic debris or concrete may be placed in deep er fill areas provided the procedures used are observed and found acceptable by our representative.

Treatment of Existing Ground

1. Following site clearing, all surficial deposits of alluvium and colluvium as well as weathered or creep effected bedrock, should be removed unless ot herwise specifically indicated in the text of this report.

2. In some cases, removal may be recommended to a spec ified depth (e.g. flat sites where partial alluvial removals may be sufficient). The contract or should not exceed these depths unless directed otherwise by our representative.

3. Groundwater existing in alluvial areas may make exc avation difficult. Deeper removals than indicated in the text of the report may be necessary due to saturation during winter months.

4. Subsequent to removals, the natural ground should b e processed to a depth of six inches, moistened to near optimum moisture conditions and compacted to fill standards.

5. Exploratory back hoe or dozer trenches still remain ing after site removal should be excavated and filled with compacted fill if they can be located.

Fill Placement

1. Unless otherwise indicated, all site soil and bedro ck may be reused for compacted fill; however, some special processing or handling may be required (see text of report).

GENERAL GRADING GUIDELINES APPENDIX C

2. Material used in the compacting process should be e venly spread, moisture conditioned, processed, and compacted in thin lifts six (6) to e ight (8) inches in compacted thickness to obtain a uniformly dense layer. The fill should be placed and compacted on a nearly horizontal plane, unless otherwise found acceptable by our representative.

3. If the moisture content or relative density varies from that recommended by this firm, the contractor should rework the fill until it is in accordance with the following:
a) Moisture content of the fill should be at or above optimum moisture. Moisture should be evenly distributed without wet and dry pockets. Pre-watering of cut or removal areas should be considered in addition to watering during fill placement, particularly in clay or dry surficial soils. The ability of the co ntractor to obtain the proper moisture content will control production rates.
b) Each six-inch layer should be compacted to at least 90 percent of the maximum dry density in compliance with the testing method speci fied by the controlling governmental agency. In most cases, the testing method is ASTM Test Designation D 1557.

4. Rock fragments less than eight inches in diameter may be utilized in the fill, provided:
a) They are not placed in concentrated pockets;
b) There is a sufficient percentage of fine-grained material to surround the rocks; c) The distribution of the rocks is observed by, and acceptable to, our representative.

5. Rocks exceeding eight (8) inches in diameter should be taken off site, broken into smaller fragments, or placed in accordance with recommendat ions of this firm in areas designated suitable for rock disposal. On projects where sign ificant large quantities of oversized materials are anticipated, alternate guidelines for placement may be included. If significant oversize materials are encountered during construction, these guidelines should be requested.

6. In clay soil, dry or large chunks or blocks are com mon. If in excess of eight (8) inches minimum dimension, then they are considered as oversized. Sheepsfoot compactors or other suitable methods should be used to break up blocks. When dry, they should be moisture conditioned to provide a uniform condition with the surrounding fill.

Slope Construction

1. The contractor should obtain a minimum relative com paction of 90 percent out to the finished slope face of fill slopes. This may be achieved by either overbuilding the slope and cutting back to the compacted core, or by direct compaction of the slope face with suitable equipment.

2. Slopes trimmed to the compacted core should be over built by at least three (3) feet with compaction efforts out to the edge of the false slo pe. Failure to properly compact the outer edge results in trimming not exposing the compacted core and additional compaction after trimming may be necessary.

3. If fill slopes are built "at grade" using direct co mpaction methods, then the slope construction should be performed so that a constant gradient is maintained throughout construction. Soil should not be "spilled" over the slope face nor sho uld slopes be "pushed out" to obtain grades.

Compaction equipment should compact each lift along the immediate top of slope. Slopes should be back rolled or otherwise compacted at app roximately every 4 feet vertically as the slope is built.

4. Corners and bends in slopes should have special att ention during construction as these are the most difficult areas to obtain proper compaction.

5. Cut slopes should be cut to the finished surface. Excessive undercutting and smoothing of the face with fill may necessitate stabilization.

GENERAL GRADING GUIDELINES APPENDIX C

UTILITY TRENCH CONSTRUCTION AND BACKFILL

Utility trench excavation and backfill is the contr actors responsibility. The geotechnical consultant typically provides periodic observation and testing of these operations. While efforts are made to ma ke sufficient observations and tests to verify that the contractors’ methods and procedures are adequate to achieve proper compaction, it is typically impracti cal to observe all backfill procedures. As such, i t is critical that the contractor use consistent backfill procedures.

Compaction methods vary for trench compaction and e xperience indicates many methods can be successful. However, procedures that “worked” on p revious projects may or may not prove effective on a given site. The contractor(s) should outline the procedures proposed, so that we may discuss them prior to construction. We will offer comments based on our knowledge of site conditions and experience.

1. Utility trench backfill in slopes, structural areas , in streets and beneath flat work or hardscape should be brought to at least optimum moisture and compacted to at least 90 percent of the laboratory standard. Soil should be moisture conditioned prior to placing in the trench.

2. Flooding and jetting are not typically recommended or acceptable for native soils. Flooding or jetting may be used with select sand having a Sand Equivalent (SE) of 30 or higher. This is typically limited to the following uses:
a) shallow (12 + inches) under slab interior trenches and, b) as bedding in pipe zone.

The water should be allowed to dissipate prior to pouring slabs or completing trench compaction.

3. Care should be taken not to place soils at high moi sture content within the upper three feet of the trench backfill in street areas, as overly wet soils may impact subgrade preparation.

Moisture may be reduced to 2% below optimum moisture in areas to be paved within the upper three feet below sub grade.

4. Sand backfill should not be allowed in exterior tre nches adjacent to and within an area extending below a 1:1 projection from the outside b ottom edge of a footing, unless it is similar to the surrounding soil.

5. Trench compaction testing is generally at the discr etion of the geotechnical consultant. Testing frequency will be based on trench depth and the con tractors procedures. A probing rod would be used to assess the consistency of compaction bet ween tested areas and untested areas. If zones are found that are considered less compact th an other areas, this would be brought to the contractors attention.

JOB SAFETY
General
Personnel safety is a primary concern on all job sites. The following summaries are safety considerations for use by all our employees on multi-employer cons truction sites. On ground personnel are at highest risk of injury and possible fatality on grading con struction projects. The company recognizes that construction activities will vary on each site and that job site safety is the contractor's responsibi lity.

However, it is, imperative that all personnel be safety conscious to avoid accidents and potential injury.

GENERAL GRADING GUIDELINES APPENDIX C

In an effort to minimize risks associated with geot echnical testing and observation, the following precautions are to be implemented for the safety of our field personnel on grading and construction projects.

1. Safety Meetings: Our field personnel are directed t o attend the contractor's regularly scheduled safety meetings.

2. Safety Vests: Safety vests are provided for and are to be worn by our personnel while on the job site.

3. Safety Flags: Safety flags are provided to our fiel d technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits.

In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office.

Test Pits Location, Orientation and Clearance
The technician is responsible for selecting test pi t locations. The primary concern is the technician 's safety. However, it is necessary to take sufficien t tests at various locations to obtain a representa tive sampling of the fill. As such, efforts will be mad e to coordinate locations with the grading contract ors authorized representatives (e.g. dump man, operator , supervisor, grade checker, etc.), and to select locations following or behind the established traff ic pattern, preferably outside of current traffic. The contractors authorized representative should direct excavation of the pit and safety during the test period. Again, safety is the paramount concern.

Test pits should be excavated so that the spoil pil e is placed away from oncoming traffic. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates that the fill be maintained in a drivable condition. Altern atively, the contractor may opt to park a piece of equipment in front of test pits, particularly in small fill areas or those with limited access.

A zone of non-encroachment should be established fo r all test pits (see diagram below). No grading equipment should enter this zone during the test pr ocedure. The zone should extend outward to the sides approximately 50 feet from the center of the test pit and 100 feet in the direction of traffic f low.

This zone is established both for safety and to avo id excessive ground vibration, which typically decreases test results.

GENERAL GRADING GUIDELINES APPENDIX C

50 ft Zone of
Non-Encroachment
50 ft Zone of
Non-Encroachment
Traffic Direction
Vehicle
parked here Test Pit Spoil
pile
Spoil
pile
Test Pit

SIDE VIEW

PLAN VIEW

TEST PIT SAFETY PLAN
10 0 ft Zone of
Non-Encroachment

Slope Tests
When taking slope tests, the technician should park their vehicle directly above or below the test location on the slope. The contractor's representa tive should effectively keep all equipment at a saf e operation distance (e.g. 50 feet) away from the slope during testing.

The technician is directed to withdraw from the act ive portion of the fill as soon as possible followi ng testing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible location.

Trench Safety
It is the contractor's responsibility to provide sa fe access into trenches where compaction testing is needed. Trenches for all utilities should be excav ated in accordance with CAL-OSHA and any other applicable safety standards. Safe conditions will be required to enable compaction testing of the tre nch backfill.

All utility trench excavations in excess of 5 feet deep, which a person enters, are to be shored or la id back. Trench access should be provided in accordan ce with OSHA standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment.

Our personnel are directed not to enter any excavation which;

1. is 5 feet or deeper unless shored or laid back,

2. exit points or ladders are not provided,

3. displays any evidence of instability, has any loose rock or other debris which could fall into the trench, or

4. displays any other evidence of any unsafe conditions regardless of depth.

If the contractor fails to provide safe access to t renches for compaction testing, our company policy requires that the soil technician withdraws and notifies their supervisor. The contractors representative will then be contacted in an effort to effect a sol ution. All backfill not tested due to safety conce rns or other reasons is subject to reprocessing and/or removal.

GENERAL GRADING GUIDELINES APPENDIX C

Procedures
In the event that the technician's safety is jeopar dized or compromised as a result of the contractor' s failure to comply with any of the above, the techni cian is directed to inform both the developer's and contractor's representatives. If the condition is not rectified, the technician is required, by compa ny policy, to immediately withdraw and notify their su pervisor. The contractor’s representative will the n be contacted in an effort to effect a solution. No further testing will be performed until the situat ion is rectified. Any fill placed in the interim can be c onsidered unacceptable and subject to reprocessing, recompaction or removal.

In the event that the soil technician does not comp ly with the above or other established safety guidelines, we request that the contractor bring th is to technicians attention and notify our project manager or office. Effective communication and coo rdination between the contractors' representative and the field technician(s) is strongly encouraged in order to implement the above safety program and safety in general.

The safety procedures outlined above should be disc ussed at the contractor's safety meetings. This wi ll serve to inform and remind equipment operators of t hese safety procedures particularly the zone of non-encroachment.

The safety procedures outlined above should be disc ussed at the contractor's safety meetings. This wi ll serve to inform and remind equipment operators of t hese safety procedures particularly the zone of non-encroachment.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: [INSERT DATE OF SWQMP]
ATTACHMENT 3
Structural BMP Maintenance Information

This is the cover sheet for Attachment 3.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 3a Structural BMP Maintenance Thresholds
and Actions (Required)

Included

See Structural BMP Maintenance
Information Checklist on the back of
this Attachment cover sheet.

Attachment 3b Draft Maintenance Agreement (when
applicable)
Included
Not Applicable

County of San Diego
Operation and Maintenance Costs forTreatment Control BMPs

ROUTINE ACTION MAINTENANCE INDICATOR FIELD MEASUREMENT MEASUREMENT FREQUENCY MAINTENANCE ACTIVITY Maintenance
Frequency (#
of times per
year)
Hours per
Event
Average
Labor Crew
Size
Labor
Rate/Hr. ($) Equipment Equipment
Cost/Hour ($)
Materials &
Incidentals
Cost or
Disposal
Cost/Event
($)
Total cost per
visit ($)
Total cost per
year ($)
Sediment Management Accumulation of sediment, litter
or debris Visual observation Monthly
Remove and properly dispose of
accumulated materials, without
damage to the vegetation or
compaction of the media layer
(expected once a year)

12.0 0.3 1  $          49.86
Utility Truck,
10‐15 yd
Truck,
Backhoe
$          56.02   $          50.00   $ 76   $ 918
Vegetation Management
Poor vegetation establishment
Dead or diseased vegetation
Visual observation Annually, prior to start of wet
season
Re‐seed, re‐plant, or re‐establish
vegetation per original plans
Remove dead or diseased vegetation,
re‐seed, re‐plant or re‐establish
vegetation per original plans
(expected every 5 years)

0.2 4.0 2  $          51.02   Utility Truck   $          14.39   $ 466   $ 93   x Vegetation Management for
Aesthetics (optional) Overgrown vegetation Visual  observation Monthly, and as needed Mow or trim as appropriate 12.0 1.0 2  $          49.86   Utility Truck   $          14.39   $          50.00   $ 164   $               1,969   x Soil Repair 2/3 of mulch has decomposed,
or mulch has been removed Visual observation Annually, and as needed Remove decomposed fraction and top
off with fresh mulch to a total depth of
3 inches

1.0 2.0 2  $          49.86   Utility Truck   $          14.39   $ 228   $ 228   x Soil Repair
Evidence of erosion due to
concentrated irrigation flow
Evidence of erosion due to
concentrated storm water
runoff  flow
Visual observation Annually, prior to start of wet
season
Repair/re‐seed/re‐plant eroded areas
and adjust the irrigation system
Repair/re‐seed/re‐plant eroded areas,
and make corrective measures such as
adding erosion control blankets,
adding stone at flow entry points, or
minor re‐grading to restore proper
drainage according to the original
plan. If the issue is not corrected by
restoring the BMP to the original plan
and grade, the [City Engineer] shall be
contacted prior to any additional
repairs or reconstruction. (expected
every 10 years)

0.1 4.0 2  $          51.02   Utility Truck   $          14.39   $        150.00   $ 616   $ 62 Standing Water
Standing water in BMP for
longer than 24 hours following a
storm event. Surface ponding
longer than approximately 24
hours following a storm event
may be detrimental to
vegetation health
Visual observation Annually,  24 hours after a
target storm event
Make appropriate corrective measures
such as adjusting irrigation system,
removing obstructions of debris or
invasive vegetation, clearing
underdrains, or repairing/replacing
clogged or compacted soils.  (expected
every 10 years)

0.1 12.0 2  $          67.74
Utility Truck,
10‐15 yd
Truck,
Backhoe
$          56.02   $ 2,298    $ 230
General Maintenance Inspection Underdrain clogged Visual observation Annually, prior to start of wet season
Clear blockage
(expected every 5 years) 0.2 4.0 2  $          49.86   Utility Truck   $          14.39   $ 456   $ 91 General Maintenance Inspection Obstruction of inlet or outlet structure Visual observation Annually, prior to start of wet season Clear blockage 1.0 0.5 2  $          49.86   Utility Truck   $          14.39   $ 57   $ 57 General Maintenance Inspection
Damage to structural
components such as weirs, inlet
or outlet structures
Visual observation Annually, prior to start of wet
season
Corrective action prior to wet season.

Consult engineers if immediate
solution is not evident.

1.0 0.5 2  $          67.74   Utility Truck   $          14.39   $ 75   $ 75 Vector Control Presence of mosquitos/larvae Visual  observation Annually If mosquitos/larvae are observed; first,
immediately remove any standing
water by dispersing to nearby
landscaping; second, make corrective
measures as applicable to restore BMP
drainage to prevent standing
water.(included in Standing Water
Maintenance Activity)

39.4           3,723 $

98.6           7,028 $         Large Biofiltration (1850sf)

EXHIBIT B

BIOFILTRATION MAINTENANCE ACTIVITIES
Average Annual Total

County of San Diego
Operation and Maintenance Costs forTreatment Control BMPs

ROUTINE ACTION MAINTENANCE INDICATOR FIELD MEASUREMENT MEASUREMENT FREQUENCY MAINTENANCE ACTIVITY Maintenance
Frequency (# of
times per year)
Hours per
Event
Average
Labor Crew
Size
Labor
Rate/Hr. ($) Equipment Equipment
Cost/Hour ($)
Materials &
Incidentals
Cost or
Disposal
Cost/Event
($)
Total cost
per visit ($)
Total cost per year
($)
Sediment Management Accumulation of sediment, litter or debris at the inlet Visual observation Monthly Remove and properly dispose of accumulated materials  12.0 0.3 1  $            49.86   Utility Truck   $            14.39  16 $             193$ Sediment Management Accumulation of sediment, litter or debris in storage container Visual observation
Semi‐annually (minimum) or
when debris accumulation is 25%
of the total container volume, or
accumulation blocks outlet,
whichever is more frequent
Remove and properly dispose of
accumulated materials. 2.0 1.0 2  $            49.86   Utility Truck, Vactor   $            77.09   $            66.67  243 $          487$   x Standing Water
Standing water in storage container between
storm events outside of normal use
timeframe for the stored water. Normal use
timeframe is 36 to 96 hours following a
storm event depending on the purpose and
design of the cistern.

Visual observation Annually,  96 hours after a target
storm event
Use the water as intended, or disperse
to landscaping. 1.0 4.0 2  $            49.86   Utility Truck   $            14.39  456 $          456$   x General Maintenance Inspection  Leaks or other damage to storage container Visual  observation Annually, prior to start of wet season
Repair or replace as applicable.
(expected every 5 years) 0.2 2.0 2  $            67.74   Utility Truck   $            14.39  300 $          60$ General Maintenance Inspection
Leaks or other damage to ancillary parts
including valves, piping, screens, level
indicators, and other accessories.

Visual observation Annually, prior to start of wet
season
Repair or replace as applicable.
(expected every 5 years) 0.2 2.0 2  $            67.74   Utility Truck   $            56.02  383 $          77$ General Maintenance Inspection  Outlet blocked Visual observation Annually, prior to start of wet season Clear blockage 1.0 0.1 2  $            49.86   Utility Truck   $            14.39  11 $             11$ General Maintenance Inspection  Cistern leaning or unstable, damage to roof, supports, anchors, or foundation Visual observation Annually, prior to start of wet season
Make repairs as appropriate to correct
the problem and stabilize the system.
(expected every 10 years)

0.1 4.0 2  $            67.74   Utility Truck   $            14.39  599 $          60$ Vector Control Presence of mosquitos/larvae Visual observation Annually If mosquitos/larvae are observed; first,
immediately remove any standing
water by using water as intended for
irrigation or alternative grey water, or
by dispersing to landscaping; second,
check cistern outlet for blockage and
clear blockage if applicable to restore
drainage; third, install barriers such as
screens that prevent mosquito access
to storage container.(included in
Standing Water Maintenance Activity)

17.6           1,344$

41.6           2,817$                Large VAULT (9,500 cf)

EXHIBIT B

STORAGE VAULT MAINTENANCE ACTIVITIES
Average Annual Total