Appendix G-1
SWQMP for the Reduced Development
Footprint Alternative – Vernal Pool Minimization
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 SOUTH
Reduced Development Footprint Alternative - Vernal
Pool Impact Minimization
Las Posas Road
San Marcos, CA 92078
ASSESSOR'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
Carlsbad, 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:
12/27/2023
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
A
cronym 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
A
PN 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 Nam
e: Pacific
Permit Application Number:
PREPARER'S C
ERTIFICATION
I hereby dec
lare 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 re
ad 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
_____12/27/2023___________ _ Date
Engineer'
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 Table 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 ☑Preliminary Design /
Planning/ CEQA
Final Design
Initial Submittal
2 3 Preliminary Design /
Planning/ CEQA
Final Design
4 Preliminary Design /
Planning/ CEQA
Final Design
12/27/2023
☑Preliminary Design /
Planning/ CEQA
Final Design
☑Preliminary Design /
Planning/ CEQA
Final Design
02/23/2024
05/08/2024
Resubmittal
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 228 residential units, including a mix of apartments, rowhomes, villas, and affordable flats on approximately 9.7 acres of the 33.2-acre project site. . The proposed project also includes landscaping, and circulation improvements. The remaining 23.5 acres of the 33.2-acre project site would be preserved and restored as 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.
Devel
opment 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 acc
ess 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.
12/27/23
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 a
ddition 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.
12/27/23
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) 9.7 Acres (____________ Square Feet)
Project Proposed Impervious Area
(subset of Project Area) 7.5 Acres (____________ Square Feet) Project Proposed Pervious Area
(subset of Project Area) 2.2 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.
1,446,192
422,532
326,700
95,832
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 towards the southwest corner of Linda Vista Drive and Las Posas
Road. This drainage is collected in a CMP (corrugated meatal p ipe) 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. Offsite run-on from DMA 10 bypasses on site BMPs.
Existing Land Cover Includes (select all that apply):
☑ Vegetative Cover
Non-Vegetated Pervious Areas
Impervious Areas
De
scription / 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
D
escription / 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) Is 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) Identify 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 southwest 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.
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 228 residential units, including a mix of apartments, rowhomes, villas, and affordable flats on approximately 9.8 acres of the 33.2-acre project site. . The proposed project also includes landscaping, and circulation improvements. The remaining 23.4 acres of the 33.2-acre project site would be preserved and restored as 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 7.8 acres of impervious area in the form of a
paved 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 2.1 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
Descriptio
n / 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 Filterra Biofiltration tree wells 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
D
escription / 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 e
xisting 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.
P
OC#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
I
f a geomorphic assessment has been performed, provide title, date, and preparer:
D
iscussion / 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 23.6 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:
H
arvest 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:
H
arvest 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 s
tructural 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 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 23.6 acres of open space (self-mitigating). (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)
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3 ) meeting all requirements of Appendix F Flo
w-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #1
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-t
hru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #2
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-t
hru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #3
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-t
hru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #4
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-th
ru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #5
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-t
hru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #6
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-t
hru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #7
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-t
hru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #8
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-t
hru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #9
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: June 6, 2022
Form I-6 Page 3 of X (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No.
Construction Plan Sheet No.
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1) Biofiltration (BF-1)
Biofiltration with Nutrient Sensitive Media Design (BF-2) Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F Flow-th
ru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
Detention pond or vault for hydromodification management Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
Combined pollutant control and hydromodification control Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Who will be the final owner of this BMP?
Who will maintain this BMP into perpetuity?
What is the funding mechanism for maintenance?
BMP #10
William Lundstrom
[email protected]
Owner
Owner
Maintenance Agreement
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.
Indi
cate which Items are Included behind this cover sheet:
Attachment
Sequence
Contents Checklist
Attachment 1a DMA Exhibit (Required)
See DM
A 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)*
*Pr
ovide 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)
Ref
er 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:
Th
e DMA Exhibit must identify:
Un
derlying 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 Units
1 Drainage Basin ID or Name DMA 1 DMA 2 DMA 3 DMA 4 DMA 5 DMA 6 DMA 7 DMA 8 unitless 2 85th Percentile 24-hr Storm Depth 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) 32,757 43,560 43,211 37,287 32,060 44,954 53,666 54,363 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) 8,190 10,890 10,803 9,322 8,015 11,238 13,416 13,590 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? No No No No No 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 #
19 Average Mature Tree Canopy Diameter ft
20 Number of Rain Barrels Proposed per SD-E #
21 Average Rain Barrel Size gal
22 Total Tributary Area 40,947 54,450 54,014 46,609 40,075 56,192 67,082 67,953 sq-ft 23 Initial Runoff Factor for Standard Drainage Areas 0.74 0.74 0.74 0.74 0.74 0.74 0.74 0.74 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 unitless 25 Initial Weighted Runoff Factor 0.74 0.74 0.74 0.74 0.74 0.74 0.74 0.74 unitless 26 Initial Design Capture Volume 1,894 2,518 2,498 2,156 1,853 2,599 3,103 3,143 cubic-feet 27 Total Impervious Area Dispersed to Pervious Surface 00000000 sq-ft 28 Total Pervious Dispersion Area 00000000 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 ratio 30 Adjustment Factor for Dispersed & Dispersion Areas 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 0.74 0.74 0.74 0.74 0.74 0.74 0.74 unitless 32 Design Capture Volume After Dispersion Techniques 1,894 2,518 2,498 2,156 1,853 2,599 3,103 3,143 cubic-feet 33 Total Tree Well Volume Reduction 00000000 cubic-feet 34 Total Rain Barrel Volume Reduction 00000000 cubic-feet 35 Final Adjusted Runoff Factor 0.74 0.74 0.74 0.74 0.74 0.74 0.74 0.74 unitless 36 Final Effective Tributary Area 30,301 40,293 39,970 34,491 29,656 41,582 49,641 50,285 sq-ft 37 Initial Design Capture Volume Retained by Site Design Elements 00000000 cubic-feet 38 Final Design Capture Volume Tributary to BMP 1,894 2,518 2,498 2,156 1,853 2,599 3,103 3,143 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 Units
1 Drainage Basin ID or Name DMA 1 DMA 2 DMA 3 DMA 4 DMA 5 DMA 6 DMA 7 DMA 8 sq-ft 2 Design Infiltration Rate Recommended 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 1,894 2,518 2,498 2,156 1,853 2,599 3,103 3,143 cubic-feet 4 Is BMP Vegetated or Unvegetated? Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated Vegetated unitless 5 Is BMP Impermeably Lined or Unlined? Lined Lined Lined Lined Lined Lined Lined Lined unitless 6 Does BMP Have an Underdrain? Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain Underdrain unitless 7 Does BMP Utilize Standard or Specialized Media? Specialized Specialized Specialized Specialized Specialized Specialized Specialized Specialized unitless 8 Provided Surface Area 72 72 72 72 72 72 91 91 sq-ft
9 Provided Surface Ponding Depth 66666666 inches
10 Provided Soil Media Thickness 21 21 21 21 21 21 21 21 inches 11 Provided Gravel Thickness (Total Thickness) 12 12 12 12 12 12 12 12 inches 12 Underdrain Offset 33333333 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 inches 14 Specialized Soil Media Filtration Rate 175.00 175.00 175.00 175.00 175.00 175.00 175.00 175.00 in/hr 15 Specialized Soil Media Pore Space for Retention unitless 16 Specialized Soil Media Pore Space for Biofiltration unitless 17 Specialized Gravel Media Pore Space unitless
18 Volume Infiltrated Over 6 Hour Storm 00000000 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 unitless 20 Soil Media Pore Space Available for Retention 0.05 0.05 0.05 0.05 0.05 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 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 unitless 23 Effective Retention Depth 2.25 2.25 2.25 2.25 2.25 2.25 2.25 2.25 inches 24 Fraction of DCV Retained (Independent of Drawdown Time) 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 ratio 25 Calculated Retention Storage Drawdown Time 120 120 120 120 120 120 120 120 hours 26 Efficacy of Retention Processes 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 ratio 27 Volume Retained by BMP (Considering Drawdown Time) 23 30 30 26 22 31 37 38 cubic-feet 28 Design Capture Volume Remaining for Biofiltration 1,871 2,488 2,468 2,130 1,831 2,568 3,066 3,105 cubic-feet 29 Max Hydromod Flow Rate through Underdrain 2.7446 2.7446 2.7446 2.7446 2.7446 2.7446 2.7446 2.7446 cfs 30 Max Soil Filtration Rate Allowed by Underdrain Orifice 1,646.79 1,646.79 1,646.79 1,646.79 1,646.79 1,646.79 1,302.95 1,302.95 in/hr 31 Soil Media Filtration Rate per Specifications 175.00 175.00 175.00 175.00 175.00 175.00 175.00 175.00 in/hr 32 Soil Media Filtration Rate to be used for Sizing 175.00 175.00 175.00 175.00 175.00 175.00 175.00 175.00 in/hr 33 Depth Biofiltered Over 6 Hour Storm 1050.00 1050.00 1050.00 1050.00 1050.00 1050.00 1050.00 1050.00 inches 34 Ponding Pore Space Available for Biofiltration 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 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 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 unitless 37 Effective Depth of Biofiltration Storage 13.80 13.80 13.80 13.80 13.80 13.80 13.80 13.80 inches 38 Drawdown Time for Surface Ponding 00000000 hours
39 Drawdown Time for Effective Biofiltration Depth 00000000 hours 40 Total Depth Biofiltered 1063.80 1063.80 1063.80 1063.80 1063.80 1063.80 1063.80 1063.80 inches 41 Option 1 - Biofilter 1.50 DCV: Target Volume 2,807 3,731 3,702 3,195 2,746 3,851 4,598 4,658 cubic-feet 42 Option 1 - Provided Biofiltration Volume 2,807 3,731 3,702 3,195 2,746 3,851 4,598 4,658 cubic-feet 43 Option 2 - Store 0.75 DCV: Target Volume 1,403 1,866 1,851 1,597 1,373 1,926 2,299 2,329 cubic-feet 44 Option 2 - Provided Storage Volume 83 83 83 83 83 83 105 105 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 ratio 46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements? 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 ratio 48 Deficit of Effectively Treated Stormwater 00000000 cubic-feet Retention
Calculations
Automated Worksheet B.3: BMP Performance (V2.0)
BMP Inputs
Biofiltration
Calculations
Result
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
BMP #9
Paficic South BMP 9 12/27/2023 9:17:16 AM Page 2
General Model Information
Project Name: Paficic South BMP 9
Site Name: Pacific
Site Address:
City: San Marcos
Report Date: 12/27/2023
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
Paficic South BMP 9 12/27/2023 9:17:16 AM Page 3
Landuse Basin Data
Predeveloped Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,NatVeg,Flat 6.7
Pervious Total 6.7
Impervious Land Use acre
Impervious Total 0
Basin Total 6.7
Element Flows To:
Surface Interflow Groundwater
Paficic South BMP 9 12/27/2023 9:17:16 AM Page 4
Mitigated Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,Urban,Flat 1.34
Pervious Total 1.34
Impervious Land Use acre
IMPERVIOUS-FLAT 5.36
Impervious Total 5.36
Basin Total 6.7
Element Flows To:
Surface Interflow Groundwater
Vault 1 Vault 1
Paficic South BMP 9 12/27/2023 9:17:16 AM Page 5
Routing Elements
Predeveloped Routing
Paficic South BMP 9 12/27/2023 9:17:16 AM Page 6
Mitigated Routing
Vault 1
Width: 94.2110799475169 ft.
Length: 94.2110799475169 ft.
Depth: 6 ft.
Discharge Structure
Riser Height: 5 ft.
Riser Diameter: 54 in.
Notch Type: Rectangular
Notch Width: 0.774 ft.
Notch Height: 1.222 ft.
Orifice 1 Diameter: 1.834 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 0.203 0.000 0.000 0.000
0.0667 0.203 0.013 0.023 0.000
0.1333 0.203 0.027 0.033 0.000
0.2000 0.203 0.040 0.040 0.000
0.2667 0.203 0.054 0.047 0.000
0.3333 0.203 0.067 0.052 0.000
0.4000 0.203 0.081 0.057 0.000
0.4667 0.203 0.095 0.062 0.000
0.5333 0.203 0.108 0.066 0.000
0.6000 0.203 0.122 0.070 0.000
0.6667 0.203 0.135 0.074 0.000
0.7333 0.203 0.149 0.078 0.000
0.8000 0.203 0.163 0.081 0.000
0.8667 0.203 0.176 0.085 0.000
0.9333 0.203 0.190 0.088 0.000
1.0000 0.203 0.203 0.091 0.000
1.0667 0.203 0.217 0.094 0.000
1.1333 0.203 0.230 0.097 0.000
1.2000 0.203 0.244 0.100 0.000
1.2667 0.203 0.258 0.102 0.000
1.3333 0.203 0.271 0.105 0.000
1.4000 0.203 0.285 0.108 0.000
1.4667 0.203 0.298 0.110 0.000
1.5333 0.203 0.312 0.113 0.000
1.6000 0.203 0.326 0.115 0.000
1.6667 0.203 0.339 0.117 0.000
1.7333 0.203 0.353 0.120 0.000
1.8000 0.203 0.366 0.122 0.000
1.8667 0.203 0.380 0.124 0.000
1.9333 0.203 0.393 0.126 0.000
2.0000 0.203 0.407 0.129 0.000
2.0667 0.203 0.421 0.131 0.000
2.1333 0.203 0.434 0.133 0.000
2.2000 0.203 0.448 0.135 0.000
2.2667 0.203 0.461 0.137 0.000
2.3333 0.203 0.475 0.139 0.000
2.4000 0.203 0.489 0.141 0.000
BMP #9
Paficic South BMP 9 12/27/2023 9:17:16 AM Page 7
2.4667 0.203 0.502 0.143 0.000
2.5333 0.203 0.516 0.145 0.000
2.6000 0.203 0.529 0.147 0.000
2.6667 0.203 0.543 0.149 0.000
2.7333 0.203 0.556 0.150 0.000
2.8000 0.203 0.570 0.152 0.000
2.8667 0.203 0.584 0.154 0.000
2.9333 0.203 0.597 0.156 0.000
3.0000 0.203 0.611 0.158 0.000
3.0667 0.203 0.624 0.159 0.000
3.1333 0.203 0.638 0.161 0.000
3.2000 0.203 0.652 0.163 0.000
3.2667 0.203 0.665 0.165 0.000
3.3333 0.203 0.679 0.166 0.000
3.4000 0.203 0.692 0.168 0.000
3.4667 0.203 0.706 0.169 0.000
3.5333 0.203 0.719 0.171 0.000
3.6000 0.203 0.733 0.173 0.000
3.6667 0.203 0.747 0.174 0.000
3.7333 0.203 0.760 0.176 0.000
3.8000 0.203 0.774 0.186 0.000
3.8667 0.203 0.787 0.247 0.000
3.9333 0.203 0.801 0.339 0.000
4.0000 0.203 0.815 0.452 0.000
4.0667 0.203 0.828 0.584 0.000
4.1333 0.203 0.842 0.732 0.000
4.2000 0.203 0.855 0.894 0.000
4.2667 0.203 0.869 1.069 0.000
4.3333 0.203 0.883 1.257 0.000
4.4000 0.203 0.896 1.456 0.000
4.4667 0.203 0.910 1.666 0.000
4.5333 0.203 0.923 1.887 0.000
4.6000 0.203 0.937 2.117 0.000
4.6667 0.203 0.950 2.357 0.000
4.7333 0.203 0.964 2.606 0.000
4.8000 0.203 0.978 2.864 0.000
4.8667 0.203 0.991 3.130 0.000
4.9333 0.203 1.005 3.405 0.000
5.0000 0.203 1.018 3.687 0.000
5.0667 0.203 1.032 4.511 0.000
5.1333 0.203 1.046 6.014 0.000
5.2000 0.203 1.059 7.958 0.000
5.2667 0.203 1.073 10.25 0.000
5.3333 0.203 1.086 12.85 0.000
5.4000 0.203 1.100 15.72 0.000
5.4667 0.203 1.113 18.81 0.000
5.5333 0.203 1.127 22.11 0.000
5.6000 0.203 1.141 25.59 0.000
5.6667 0.203 1.154 29.21 0.000
5.7333 0.203 1.168 32.96 0.000
5.8000 0.203 1.181 36.81 0.000
5.8667 0.203 1.195 40.72 0.000
5.9333 0.203 1.209 44.67 0.000
6.0000 0.203 1.222 48.64 0.000
6.0667 0.203 1.236 52.59 0.000
6.1333 0.000 0.000 56.49 0.000
Paficic South BMP 9 12/27/2023 9:17:16 AM Page 8
Analysis Results
POC 1
+ Predeveloped x Mitigated
Predeveloped Landuse Totals for POC #1
Total Pervious Area: 6.7
Total Impervious Area: 0
Mitigated Landuse Totals for POC #1
Total Pervious Area: 1.34
Total Impervious Area: 5.36
Flow Frequency Method: Cunnane
Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs)
2 year 1.754844
5 year 2.907728
10 year 3.350574
25 year 3.790257
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 0.490604
5 year 2.150795
10 year 2.959398
25 year 3.603764
Paficic South BMP 9 12/27/2023 9:17:22 AM Page 9
Duration Flows
The Facility PASSED
Flow(cfs) Predev Mit Percentage Pass/Fail
0.1755 762 670 87 Pass
0.2076 668 480 71 Pass
0.2396 611 410 67 Pass
0.2717 541 374 69 Pass
0.3038 478 346 72 Pass
0.3358 425 312 73 Pass
0.3679 376 288 76 Pass
0.4000 335 270 80 Pass
0.4321 306 254 83 Pass
0.4641 290 239 82 Pass
0.4962 278 225 80 Pass
0.5283 265 209 78 Pass
0.5603 254 196 77 Pass
0.5924 238 186 78 Pass
0.6245 227 177 77 Pass
0.6566 215 173 80 Pass
0.6886 205 167 81 Pass
0.7207 199 160 80 Pass
0.7528 191 155 81 Pass
0.7848 184 149 80 Pass
0.8169 179 143 79 Pass
0.8490 172 137 79 Pass
0.8811 168 129 76 Pass
0.9131 159 119 74 Pass
0.9452 153 111 72 Pass
0.9773 140 106 75 Pass
1.0093 128 97 75 Pass
1.0414 109 92 84 Pass
1.0735 98 89 90 Pass
1.1056 93 83 89 Pass
1.1376 92 81 88 Pass
1.1697 87 77 88 Pass
1.2018 84 73 86 Pass
1.2338 80 71 88 Pass
1.2659 74 69 93 Pass
1.2980 72 69 95 Pass
1.3301 70 69 98 Pass
1.3621 70 66 94 Pass
1.3942 66 62 93 Pass
1.4263 66 60 90 Pass
1.4583 64 55 85 Pass
1.4904 58 52 89 Pass
1.5225 55 50 90 Pass
1.5546 53 44 83 Pass
1.5866 50 41 82 Pass
1.6187 47 40 85 Pass
1.6508 46 39 84 Pass
1.6829 44 37 84 Pass
1.7149 44 35 79 Pass
1.7470 42 35 83 Pass
1.7791 41 33 80 Pass
1.8111 41 29 70 Pass
1.8432 39 29 74 Pass
Paficic South BMP 9 12/27/2023 9:17:22 AM Page 10
1.8753 38 28 73 Pass
1.9074 36 26 72 Pass
1.9394 34 25 73 Pass
1.9715 33 25 75 Pass
2.0036 31 25 80 Pass
2.0356 30 24 80 Pass
2.0677 29 22 75 Pass
2.0998 27 21 77 Pass
2.1319 27 21 77 Pass
2.1639 27 18 66 Pass
2.1960 25 18 72 Pass
2.2281 25 18 72 Pass
2.2601 25 18 72 Pass
2.2922 24 18 75 Pass
2.3243 24 18 75 Pass
2.3564 23 17 73 Pass
2.3884 23 17 73 Pass
2.4205 23 16 69 Pass
2.4526 23 15 65 Pass
2.4846 23 15 65 Pass
2.5167 23 14 60 Pass
2.5488 23 14 60 Pass
2.5809 23 14 60 Pass
2.6129 22 14 63 Pass
2.6450 21 14 66 Pass
2.6771 19 14 73 Pass
2.7091 18 11 61 Pass
2.7412 16 11 68 Pass
2.7733 15 11 73 Pass
2.8054 14 10 71 Pass
2.8374 13 10 76 Pass
2.8695 12 10 83 Pass
2.9016 12 9 75 Pass
2.9336 11 9 81 Pass
2.9657 10 9 90 Pass
2.9978 10 8 80 Pass
3.0299 10 8 80 Pass
3.0619 10 7 70 Pass
3.0940 9 7 77 Pass
3.1261 9 7 77 Pass
3.1581 8 7 87 Pass
3.1902 8 6 75 Pass
3.2223 7 6 85 Pass
3.2544 5 5 100 Pass
3.2864 4 4 100 Pass
3.3185 4 4 100 Pass
3.3506 4 4 100 Pass
Paficic South BMP 9 12/27/2023 9:17:22 AM Page 11
Water Quality
Drawdown Time Results
Pond: Vault 1
Days Stage(feet) Percent of Total Run Time
1 0.567 4.1589
2 1.514 1.6943
3 2.885 0.4668
4 0.000 N/A
5 0.000 N/A
Maximum Stage: 5.000 Drawdown Time: 03 12:29:30
Paficic South BMP 9 12/27/2023 9:17:22 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.
Paficic South BMP 9 12/27/2023 9:17:22 AM Page 13
Appendix
Predeveloped Schematic
Paficic South BMP 9 12/27/2023 9:17:22 AM Page 14
Mitigated Schematic
Paficic South BMP 9 12/27/2023 9:17:23 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 Paficic South BMP 9.wdm
MESSU 25 PrePaficic South BMP 9.MES
27 PrePaficic South BMP 9.L61
28 PrePaficic South BMP 9.L62
30 POCPaficic South BMP 91.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
Paficic South BMP 9 12/27/2023 9:17:23 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
Paficic South BMP 9 12/27/2023 9:17:23 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 6.7 COPY 501 12 PERLND 28 6.7 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
Paficic South BMP 9 12/27/2023 9:17:23 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
Paficic South BMP 9 12/27/2023 9:17:23 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 Paficic South BMP 9.wdm
MESSU 25 MitPaficic South BMP 9.MES
27 MitPaficic South BMP 9.L61
28 MitPaficic South BMP 9.L62
30 POCPaficic South BMP 91.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 ********* Paficic South BMP 9 12/27/2023 9:17:23 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
Paficic South BMP 9 12/27/2023 9:17:23 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 1.34 RCHRES 1 2 PERLND 46 1.34 RCHRES 1 3 IMPLND 1 5.36 RCHRES 1 5 ******Routing******
PERLND 46 1.34 COPY 1 12 IMPLND 1 5.36 COPY 1 15 PERLND 46 1.34 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
Paficic South BMP 9 12/27/2023 9:17:23 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 0.02 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 0.203759 0.000000 0.000000
0.066667 0.203759 0.013584 0.023567
0.133333 0.203759 0.027168 0.033329
0.200000 0.203759 0.040752 0.040820
0.266667 0.203759 0.054336 0.047135
0.333333 0.203759 0.067920 0.052698
0.400000 0.203759 0.081503 0.057728
0.466667 0.203759 0.095087 0.062353
0.533333 0.203759 0.108671 0.066659
0.600000 0.203759 0.122255 0.070702
0.666667 0.203759 0.135839 0.074527
0.733333 0.203759 0.149423 0.078164
0.800000 0.203759 0.163007 0.081640
0.866667 0.203759 0.176591 0.084973
0.933333 0.203759 0.190175 0.088181
1.000000 0.203759 0.203759 0.091276
1.066667 0.203759 0.217343 0.094270
1.133333 0.203759 0.230926 0.097171
1.200000 0.203759 0.244510 0.099988
1.266667 0.203759 0.258094 0.102728
1.333333 0.203759 0.271678 0.105397
1.400000 0.203759 0.285262 0.107999
1.466667 0.203759 0.298846 0.110541
1.533333 0.203759 0.312430 0.113025
1.600000 0.203759 0.326014 0.115456
1.666667 0.203759 0.339598 0.117837
1.733333 0.203759 0.353182 0.120171
1.800000 0.203759 0.366766 0.122460
1.866667 0.203759 0.380350 0.124707
1.933333 0.203759 0.393933 0.126914
2.000000 0.203759 0.407517 0.129084
2.066667 0.203759 0.421101 0.131218
2.133333 0.203759 0.434685 0.133317
2.200000 0.203759 0.448269 0.135384
2.266667 0.203759 0.461853 0.137420
2.333333 0.203759 0.475437 0.139427
2.400000 0.203759 0.489021 0.141404
2.466667 0.203759 0.502605 0.143355
2.533333 0.203759 0.516189 0.145279
2.600000 0.203759 0.529773 0.147178
2.666667 0.203759 0.543356 0.149053
2.733333 0.203759 0.556940 0.150905
Paficic South BMP 9 12/27/2023 9:17:23 AM Page 23
2.800000 0.203759 0.570524 0.152734
2.866667 0.203759 0.584108 0.154542
2.933333 0.203759 0.597692 0.156328
3.000000 0.203759 0.611276 0.158095
3.066667 0.203759 0.624860 0.159842
3.133333 0.203759 0.638444 0.161570
3.200000 0.203759 0.652028 0.163280
3.266667 0.203759 0.665612 0.164972
3.333333 0.203759 0.679196 0.166647
3.400000 0.203759 0.692779 0.168305
3.466667 0.203759 0.706363 0.169947
3.533333 0.203759 0.719947 0.171573
3.600000 0.203759 0.733531 0.173184
3.666667 0.203759 0.747115 0.174781
3.733333 0.203759 0.760699 0.176362
3.800000 0.203759 0.774283 0.186470
3.866667 0.203759 0.787867 0.247806
3.933333 0.203759 0.801451 0.339191
4.000000 0.203759 0.815035 0.452617
4.066667 0.203759 0.828619 0.584364
4.133333 0.203759 0.842202 0.732142
4.200000 0.203759 0.855786 0.894351
4.266667 0.203759 0.869370 1.069794
4.333333 0.203759 0.882954 1.257530
4.400000 0.203759 0.896538 1.456794
4.466667 0.203759 0.910122 1.666950
4.533333 0.203759 0.923706 1.887454
4.600000 0.203759 0.937290 2.117839
4.666667 0.203759 0.950874 2.357695
4.733333 0.203759 0.964458 2.606658
4.800000 0.203759 0.978042 2.864405
4.866667 0.203759 0.991626 3.130644
4.933333 0.203759 1.005209 3.405111
5.000000 0.203759 1.018793 3.687565
5.066667 0.203759 1.032377 4.511009
5.133333 0.203759 1.045961 6.014043
5.200000 0.203759 1.059545 7.958096
5.266667 0.203759 1.073129 10.25662
5.333333 0.203759 1.086713 12.85723
5.400000 0.203759 1.100297 15.72152
5.466667 0.203759 1.113881 18.81769
5.533333 0.203759 1.127465 22.11718
5.600000 0.203759 1.141049 25.59289
5.666667 0.203759 1.154632 29.21819
5.733333 0.203759 1.168216 32.96638
5.800000 0.203759 1.181800 36.81042
5.866667 0.203759 1.195384 40.72283
5.933333 0.203759 1.208968 44.67575
6.000000 0.203759 1.222552 48.64107
6.066667 0.203759 1.236136 52.59062
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 1000 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1001 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 12.1 WDM 701 FLOW ENGL REPL Paficic South BMP 9 12/27/2023 9:17:23 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
Paficic South BMP 9 12/27/2023 9:17:23 AM Page 25
Predeveloped HSPF Message File
Paficic South BMP 9 12/27/2023 9:17:23 AM Page 26
Mitigated HSPF Message File
Paficic South BMP 9 12/27/2023 9:17:23 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. 2005-2023; 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
BMP #10
Paficic South BMP 10 12/27/2023 9:21:41 AM Page 2
General Model Information
Project Name: Paficic South BMP 10
Site Name: Pacific
Site Address:
City: San Marcos
Report Date: 12/27/2023
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
Paficic South BMP 10 12/27/2023 9:21:41 AM Page 3
Landuse Basin Data
Predeveloped Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,NatVeg,Flat 3.1
Pervious Total 3.1
Impervious Land Use acre
Impervious Total 0
Basin Total 3.1
Element Flows To:
Surface Interflow Groundwater
Paficic South BMP 10 12/27/2023 9:21:41 AM Page 4
Mitigated Land Use
Basin 1
Bypass: No
GroundWater: No
Pervious Land Use acre
D,Urban,Flat 0.62
Pervious Total 0.62
Impervious Land Use acre
IMPERVIOUS-FLAT 2.48
Impervious Total 2.48
Basin Total 3.1
Element Flows To:
Surface Interflow Groundwater
Vault 1 Vault 1
Paficic South BMP 10 12/27/2023 9:21:41 AM Page 5
Routing Elements
Predeveloped Routing
Paficic South BMP 10 12/27/2023 9:21:41 AM Page 6
Mitigated Routing
Vault 1
Width: 63.6438694604565 ft.
Length: 63.6438694604565 ft.
Depth: 6 ft.
Discharge Structure
Riser Height: 5 ft.
Riser Diameter: 54 in.
Notch Type: Rectangular
Notch Width: 0.393 ft.
Notch Height: 1.479 ft.
Orifice 1 Diameter: 1.262 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 0.093 0.000 0.000 0.000
0.0667 0.093 0.006 0.011 0.000
0.1333 0.093 0.012 0.015 0.000
0.2000 0.093 0.018 0.019 0.000
0.2667 0.093 0.024 0.022 0.000
0.3333 0.093 0.031 0.025 0.000
0.4000 0.093 0.037 0.027 0.000
0.4667 0.093 0.043 0.029 0.000
0.5333 0.093 0.049 0.031 0.000
0.6000 0.093 0.055 0.033 0.000
0.6667 0.093 0.062 0.035 0.000
0.7333 0.093 0.068 0.037 0.000
0.8000 0.093 0.074 0.038 0.000
0.8667 0.093 0.080 0.040 0.000
0.9333 0.093 0.086 0.041 0.000
1.0000 0.093 0.093 0.043 0.000
1.0667 0.093 0.099 0.044 0.000
1.1333 0.093 0.105 0.046 0.000
1.2000 0.093 0.111 0.047 0.000
1.2667 0.093 0.117 0.048 0.000
1.3333 0.093 0.124 0.049 0.000
1.4000 0.093 0.130 0.051 0.000
1.4667 0.093 0.136 0.052 0.000
1.5333 0.093 0.142 0.053 0.000
1.6000 0.093 0.148 0.054 0.000
1.6667 0.093 0.155 0.055 0.000
1.7333 0.093 0.161 0.056 0.000
1.8000 0.093 0.167 0.058 0.000
1.8667 0.093 0.173 0.059 0.000
1.9333 0.093 0.179 0.060 0.000
2.0000 0.093 0.186 0.061 0.000
2.0667 0.093 0.192 0.062 0.000
2.1333 0.093 0.198 0.063 0.000
2.2000 0.093 0.204 0.064 0.000
2.2667 0.093 0.210 0.065 0.000
2.3333 0.093 0.217 0.066 0.000
2.4000 0.093 0.223 0.067 0.000
BMP #10
Paficic South BMP 10 12/27/2023 9:21:41 AM Page 7
2.4667 0.093 0.229 0.067 0.000
2.5333 0.093 0.235 0.068 0.000
2.6000 0.093 0.241 0.069 0.000
2.6667 0.093 0.248 0.070 0.000
2.7333 0.093 0.254 0.071 0.000
2.8000 0.093 0.260 0.072 0.000
2.8667 0.093 0.266 0.073 0.000
2.9333 0.093 0.272 0.074 0.000
3.0000 0.093 0.279 0.074 0.000
3.0667 0.093 0.285 0.075 0.000
3.1333 0.093 0.291 0.076 0.000
3.2000 0.093 0.297 0.077 0.000
3.2667 0.093 0.303 0.078 0.000
3.3333 0.093 0.310 0.078 0.000
3.4000 0.093 0.316 0.079 0.000
3.4667 0.093 0.322 0.080 0.000
3.5333 0.093 0.328 0.083 0.000
3.6000 0.093 0.334 0.110 0.000
3.6667 0.093 0.341 0.153 0.000
3.7333 0.093 0.347 0.206 0.000
3.8000 0.093 0.353 0.266 0.000
3.8667 0.093 0.359 0.332 0.000
3.9333 0.093 0.365 0.403 0.000
4.0000 0.093 0.372 0.478 0.000
4.0667 0.093 0.378 0.556 0.000
4.1333 0.093 0.384 0.637 0.000
4.2000 0.093 0.390 0.721 0.000
4.2667 0.093 0.396 0.806 0.000
4.3333 0.093 0.402 0.892 0.000
4.4000 0.093 0.409 0.979 0.000
4.4667 0.093 0.415 1.066 0.000
4.5333 0.093 0.421 1.158 0.000
4.6000 0.093 0.427 1.265 0.000
4.6667 0.093 0.433 1.376 0.000
4.7333 0.093 0.440 1.491 0.000
4.8000 0.093 0.446 1.608 0.000
4.8667 0.093 0.452 1.729 0.000
4.9333 0.093 0.458 2.415 0.000
5.0000 0.093 0.464 2.582 0.000
5.0667 0.093 0.471 3.404 0.000
5.1333 0.093 0.477 4.907 0.000
5.2000 0.093 0.483 6.850 0.000
5.2667 0.093 0.489 9.148 0.000
5.3333 0.093 0.495 11.74 0.000
5.4000 0.093 0.502 14.61 0.000
5.4667 0.093 0.508 17.70 0.000
5.5333 0.093 0.514 21.00 0.000
5.6000 0.093 0.520 24.48 0.000
5.6667 0.093 0.526 28.10 0.000
5.7333 0.093 0.533 31.85 0.000
5.8000 0.093 0.539 35.69 0.000
5.8667 0.093 0.545 39.60 0.000
5.9333 0.093 0.551 43.56 0.000
6.0000 0.093 0.557 47.52 0.000
6.0667 0.093 0.564 51.47 0.000
6.1333 0.000 0.000 55.37 0.000
Paficic South BMP 10 12/27/2023 9:21:41 AM Page 8
Analysis Results
POC 1
+ Predeveloped x Mitigated
Predeveloped Landuse Totals for POC #1
Total Pervious Area: 3.1
Total Impervious Area: 0
Mitigated Landuse Totals for POC #1
Total Pervious Area: 0.62
Total Impervious Area: 2.48
Flow Frequency Method: Cunnane
Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs)
2 year 0.811943
5 year 1.345367
10 year 1.550266
25 year 1.753701
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 0.258963
5 year 1.012188
10 year 1.362031
25 year 1.610507
Paficic South BMP 10 12/27/2023 9:21:47 AM Page 9
Duration Flows
The Facility PASSED
Flow(cfs) Predev Mit Percentage Pass/Fail
0.0812 762 663 87 Pass
0.0960 666 519 77 Pass
0.1109 613 453 73 Pass
0.1257 543 412 75 Pass
0.1406 478 387 80 Pass
0.1554 425 349 82 Pass
0.1702 376 323 85 Pass
0.1851 334 302 90 Pass
0.1999 307 282 91 Pass
0.2147 290 262 90 Pass
0.2296 278 247 88 Pass
0.2444 265 229 86 Pass
0.2593 254 217 85 Pass
0.2741 238 205 86 Pass
0.2889 227 199 87 Pass
0.3038 217 190 87 Pass
0.3186 205 187 91 Pass
0.3335 199 174 87 Pass
0.3483 191 168 87 Pass
0.3631 184 160 86 Pass
0.3780 179 154 86 Pass
0.3928 172 148 86 Pass
0.4077 168 134 79 Pass
0.4225 159 130 81 Pass
0.4373 153 118 77 Pass
0.4522 140 114 81 Pass
0.4670 127 108 85 Pass
0.4819 109 100 91 Pass
0.4967 98 98 100 Pass
0.5115 93 90 96 Pass
0.5264 92 85 92 Pass
0.5412 87 81 93 Pass
0.5560 84 78 92 Pass
0.5709 80 75 93 Pass
0.5857 74 71 95 Pass
0.6006 72 69 95 Pass
0.6154 70 69 98 Pass
0.6302 70 67 95 Pass
0.6451 66 64 96 Pass
0.6599 66 63 95 Pass
0.6748 64 59 92 Pass
0.6896 58 56 96 Pass
0.7044 56 54 96 Pass
0.7193 53 48 90 Pass
0.7341 50 45 90 Pass
0.7490 47 43 91 Pass
0.7638 46 42 91 Pass
0.7786 44 38 86 Pass
0.7935 44 37 84 Pass
0.8083 42 35 83 Pass
0.8231 41 32 78 Pass
0.8380 41 31 75 Pass
0.8528 39 29 74 Pass
Paficic South BMP 10 12/27/2023 9:21:47 AM Page 10
0.8677 38 28 73 Pass
0.8825 36 28 77 Pass
0.8973 34 28 82 Pass
0.9122 33 27 81 Pass
0.9270 31 25 80 Pass
0.9419 30 25 83 Pass
0.9567 29 23 79 Pass
0.9715 27 21 77 Pass
0.9864 27 19 70 Pass
1.0012 27 19 70 Pass
1.0161 25 19 76 Pass
1.0309 25 18 72 Pass
1.0457 25 18 72 Pass
1.0606 24 18 75 Pass
1.0754 24 18 75 Pass
1.0903 23 18 78 Pass
1.1051 23 16 69 Pass
1.1199 23 16 69 Pass
1.1348 23 15 65 Pass
1.1496 23 14 60 Pass
1.1644 23 14 60 Pass
1.1793 23 14 60 Pass
1.1941 23 14 60 Pass
1.2090 22 13 59 Pass
1.2238 21 13 61 Pass
1.2386 19 13 68 Pass
1.2535 18 13 72 Pass
1.2683 16 12 75 Pass
1.2832 15 12 80 Pass
1.2980 14 11 78 Pass
1.3128 13 9 69 Pass
1.3277 12 9 75 Pass
1.3425 12 9 75 Pass
1.3574 11 9 81 Pass
1.3722 10 8 80 Pass
1.3870 10 8 80 Pass
1.4019 10 8 80 Pass
1.4167 10 8 80 Pass
1.4316 9 8 88 Pass
1.4464 9 7 77 Pass
1.4612 8 7 87 Pass
1.4761 8 7 87 Pass
1.4909 7 7 100 Pass
1.5057 5 5 100 Pass
1.5206 4 4 100 Pass
1.5354 4 3 75 Pass
1.5503 4 3 75 Pass
Paficic South BMP 10 12/27/2023 9:21:47 AM Page 11
Water Quality
Drawdown Time Results
Pond: Vault 1
Days Stage(feet) Percent of Total Run Time
1 0.567 4.1589
2 1.514 1.6943
3 2.885 0.4668
4 0.000 N/A
5 0.000 N/A
Maximum Stage: 5.000 Drawdown Time: 03 12:29:30
Paficic South BMP 10 12/27/2023 9:21:47 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.
Paficic South BMP 10 12/27/2023 9:21:47 AM Page 13
Appendix
Predeveloped Schematic
Paficic South BMP 10 12/27/2023 9:21:47 AM Page 14
Mitigated Schematic
Paficic South BMP 10 12/27/2023 9:21:48 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 Paficic South BMP 10.wdm
MESSU 25 PrePaficic South BMP 10.MES
27 PrePaficic South BMP 10.L61
28 PrePaficic South BMP 10.L62
30 POCPaficic South BMP 101.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
Paficic South BMP 10 12/27/2023 9:21:48 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
Paficic South BMP 10 12/27/2023 9:21:48 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 3.1 COPY 501 12 PERLND 28 3.1 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
Paficic South BMP 10 12/27/2023 9:21:48 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
Paficic South BMP 10 12/27/2023 9:21:48 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 Paficic South BMP 10.wdm
MESSU 25 MitPaficic South BMP 10.MES
27 MitPaficic South BMP 10.L61
28 MitPaficic South BMP 10.L62
30 POCPaficic South BMP 101.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 ********* Paficic South BMP 10 12/27/2023 9:21:48 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
Paficic South BMP 10 12/27/2023 9:21:48 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 0.62 RCHRES 1 2 PERLND 46 0.62 RCHRES 1 3 IMPLND 1 2.48 RCHRES 1 5 ******Routing******
PERLND 46 0.62 COPY 1 12 IMPLND 1 2.48 COPY 1 15 PERLND 46 0.62 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
Paficic South BMP 10 12/27/2023 9:21:48 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 0.092988 0.000000 0.000000
0.066667 0.092988 0.006199 0.011159
0.133333 0.092988 0.012398 0.015781
0.200000 0.092988 0.018598 0.019328
0.266667 0.092988 0.024797 0.022318
0.333333 0.092988 0.030996 0.024953
0.400000 0.092988 0.037195 0.027334
0.466667 0.092988 0.043394 0.029524
0.533333 0.092988 0.049593 0.031563
0.600000 0.092988 0.055793 0.033478
0.666667 0.092988 0.061992 0.035288
0.733333 0.092988 0.068191 0.037011
0.800000 0.092988 0.074390 0.038656
0.866667 0.092988 0.080589 0.040235
0.933333 0.092988 0.086788 0.041754
1.000000 0.092988 0.092988 0.043219
1.066667 0.092988 0.099187 0.044637
1.133333 0.092988 0.105386 0.046010
1.200000 0.092988 0.111585 0.047344
1.266667 0.092988 0.117784 0.048642
1.333333 0.092988 0.123984 0.049905
1.400000 0.092988 0.130183 0.051138
1.466667 0.092988 0.136382 0.052341
1.533333 0.092988 0.142581 0.053517
1.600000 0.092988 0.148780 0.054669
1.666667 0.092988 0.154979 0.055796
1.733333 0.092988 0.161179 0.056901
1.800000 0.092988 0.167378 0.057985
1.866667 0.092988 0.173577 0.059049
1.933333 0.092988 0.179776 0.060094
2.000000 0.092988 0.185975 0.061121
2.066667 0.092988 0.192174 0.062132
2.133333 0.092988 0.198374 0.063126
2.200000 0.092988 0.204573 0.064105
2.266667 0.092988 0.210772 0.065069
2.333333 0.092988 0.216971 0.066019
2.400000 0.092988 0.223170 0.066955
2.466667 0.092988 0.229370 0.067879
2.533333 0.092988 0.235569 0.068790
2.600000 0.092988 0.241768 0.069689
2.666667 0.092988 0.247967 0.070577
2.733333 0.092988 0.254166 0.071454
Paficic South BMP 10 12/27/2023 9:21:48 AM Page 23
2.800000 0.092988 0.260365 0.072320
2.866667 0.092988 0.266565 0.073176
2.933333 0.092988 0.272764 0.074022
3.000000 0.092988 0.278963 0.074858
3.066667 0.092988 0.285162 0.075685
3.133333 0.092988 0.291361 0.076503
3.200000 0.092988 0.297560 0.077313
3.266667 0.092988 0.303760 0.078114
3.333333 0.092988 0.309959 0.078907
3.400000 0.092988 0.316158 0.079692
3.466667 0.092988 0.322357 0.080470
3.533333 0.092988 0.328556 0.083004
3.600000 0.092988 0.334756 0.110537
3.666667 0.092988 0.340955 0.153303
3.733333 0.092988 0.347154 0.205998
3.800000 0.092988 0.353353 0.266208
3.866667 0.092988 0.359552 0.332401
3.933333 0.092988 0.365751 0.403462
4.000000 0.092988 0.371951 0.478522
4.066667 0.092988 0.378150 0.556870
4.133333 0.092988 0.384349 0.637902
4.200000 0.092988 0.390548 0.721094
4.266667 0.092988 0.396747 0.805985
4.333333 0.092988 0.402946 0.892159
4.400000 0.092988 0.409146 0.979238
4.466667 0.092988 0.415345 1.066878
4.533333 0.092988 0.421544 1.158016
4.600000 0.092988 0.427743 1.265718
4.666667 0.092988 0.433942 1.376775
4.733333 0.092988 0.440142 1.491088
4.800000 0.092988 0.446341 1.608566
4.866667 0.092988 0.452540 1.729126
4.933333 0.092988 0.458739 2.415240
5.000000 0.092988 0.464938 2.582036
5.066667 0.092988 0.471137 3.404766
5.133333 0.092988 0.477337 4.907091
5.200000 0.092988 0.483536 6.850439
5.266667 0.092988 0.489735 9.148262
5.333333 0.092988 0.495934 11.74818
5.400000 0.092988 0.502133 14.61178
5.466667 0.092988 0.508332 17.70726
5.533333 0.092988 0.514532 21.00606
5.600000 0.092988 0.520731 24.48110
5.666667 0.092988 0.526930 28.10573
5.733333 0.092988 0.533129 31.85324
5.800000 0.092988 0.539328 35.69661
5.866667 0.092988 0.545528 39.60836
5.933333 0.092988 0.551727 43.56063
6.000000 0.092988 0.557926 47.52529
6.066667 0.092988 0.564125 51.47418
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 1000 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1001 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 12.1 WDM 701 FLOW ENGL REPL Paficic South BMP 10 12/27/2023 9:21:48 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
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Predeveloped HSPF Message File
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Mitigated HSPF Message File
Paficic South BMP 10 12/27/2023 9:21:48 AM Page 27
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GEOTECHNICAL | ENVIRONMENTAL | MATERIALS
December 5, 2023
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 Reduced Development Footprint Alter native – South Plan Corner of Linda Vista Drive & Los Posas Road
San Marcos, California
Dear Mr. Waite:
This memorandum (memo) presents a discussion in reg ard to a development plan that is alternative to the Reduced Pacific Specific Plan at the subject project location. An updated project discussion, conclusions and recommendations are presented in this memo. The following sections supersede those sections referen ced in GeoTek’s preliminary soils report for the Reduced Pacific Specific Plan, dated Decemb er 5, 2023.
2.2 Future Development / Project Description
This Revised Reduced Development Footprint Alternative – South Plan would occur only within a reduced development footprint in the southern por tion of the Project site, resulting in the development of only 228 multi-family homes and achi eve a 29% maximum building footprint at the site. An updated Boring Location Map is presen ted as Figure 2 and attached to this memo.
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 Indust rial (I) to Specific Plan Area (SPA). The Specific Plan has been prepared with the intent to provide a comprehensive plan to ensure the efficient development of a new residential comm unity. The Specific Plan serves as both a policy document and a regulatory document for the s ystematic implementation of the policies and goals of the General Plan. The Tentative Map pr esents specific lot configurations for the THE LAS POSAS OWNER LPV, LLC. Project No. 3649-SD
Revised Reduced Development Footprint Alternative – South Plan December 5, 2023 Corner of Linda Vista & Las Posas, San Marcos, California Page 2
site. The Multi-Family Site Development Plan will c onfigure the site for multi family dwelling units, street configuration, infrastructure, recrea tional open space, and private open space.
As part of the project, additional pedestrian conne ctivity would be provided along three of the adjacent street frontages. The project would pr ovide a 6-foot sidewalk and Class II buffered bike lane along the project’s frontage on Pacific Street; the project would provide a 12-foot urban trail (shared use path) along the pro ject’s frontage on Linda Vista Drive; and the project would also provide a 12-foot urban trai l (shared use path) along the project’s frontage on La Mirada Drive. In addition to the pro posed sidewalk and trail connections, the project would add a bus stop and shelter with a bus turnout along South Las Posas Road adjacent to the development area and would install a 4-way traffic signal at the intersection of Linda Vista Drive and Pacific Street. Furthermor e, the project would upsize approximately 1,458-feet of existing water pipe from 8-inches to 12-inches and would convert approximately 1,400-feet of existing overhead power lines to underground along La Mirada.
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.
5.0 Conclusions and recommendations
5.1 General
Future development of the property appears feasible from a geotechnical viewpoint provided that the recommendations presented in GeoTek’s referenced 2023 report are incorporated into the design, construction, and post construction phases of the project. Due to the preliminary nature of this report, supplemental geotechnical evaluatio ns of the property are anticipated at future dates once more detailed development plans are avai lable. Those supplemental geotechnical recommendations will supersede the preliminary recommendations provided in this report.
THE LAS POSAS OWNER LPV, LLC. Project No. 3649-SD
Revised Reduced Development Footprint Alternative – South Plan December 5, 2023 Corner of Linda Vista & Las Posas, San Marcos, California Page 3
Closure
The opportunity to be of service is sincerely 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
Pr incipal Geologist
Selected References
GeoTek, Inc. 2023, Reduced Pacific Specific Plan Project, Northwest Corner of Linda Vista, Drive & Los Posas Road, San Marcos, California, Project Number 3649-SD, dated December 5, 2023.
ENCLOSURES
Figure 2 – Boring Location Map
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
Revised Reduced Development Footprint
Alternative – South Plan
Linda Vista Dr. & Las Posas Rd
San Marcos, California
PN: 3649-SD December 2023
Figure 2
Boring Location
Plan
B-6
Tsa
Qal
Tsa
Qal
Tsa
P-1
P-2
B-6
B-3
B-4
B-5
Not to scale
GEOTECHNICAL | ENVIRONMENTAL | MATERIALS
The Las Posas Owner LPV, LLC,
A Delaware Limited Liability Company
2235 Encinitas Boulevard, Suite 216
Encinitas, California 92024
Attention: Mr. Greg Waite
Subject: Reduced Development Footprint Alternative –
Vernal Pool Impact Minimization Plan
Corner of Linda Vista Drive & Los Posas Road
San Marcos, California
Dear Mr. Waite:
2.2 Future Development / Project Description
Under the Reduced Development Footprint Alternative – Vernal Pool Impact Minimization, development would occur within a reduced development footprint in the southern portion of the Project site. The reduced development consists of 228 residential units, including a mix of rowhomes and villas on approximately 9.7 acres of the 33.2-acre project site. The reduced development includes a total of 532 parking spaces and 82,311 square feet of common open space area. The reduced development also includes landscaping, bio-retention areas, and circulation improvements. The remaining approximately 23.5 acres of the 33.2-acre project site would be preserved and restored as open space and habitat area. The reduced development would have a density of approximately 6.86 dwelling units per acre, including the open space and habitat area.
As planning progresses and additional or revised plans become available, they should be provided to GeoTek for review and comment. If plans vary significantly, additional geotechnical field May 8, 2024
Project No. 3649-SD
This memorandum (memo) presents a discussion in regard to a development plan for the subject project location. An updated project discussion, conclusions, and recommendations are presented in this memo.
exploration, laboratory testing and engineering analyses may be necessary to provide specific earthwork recommendations and geotechnical design parameters for actual development plans.
5.0 Conclusions and recommendations
5.1 General
The Reduced Development Footprint Alternative – Vernal Pool Impact Minimization was compared to the findings, conclusions , and recommendations presented in GeoTek’s December 5, 2023 report and a revised report is not recommended at this time. An updated Boring Location Plan presenting the Reduced Development Footprint Alternative – Vernal Pool Impact Minimization is presented as Figure 2. Future development of the property appears feasible from a geotechnical viewpoint provided that the recommendations presented in GeoTek’s referenced December 5, 2023 report are incorporated into the design, construction, and post construction phases of the project. 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.
Closure
The opportunity to be of service is sincerely 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 Principal Geologist ENCLOSURES Figure 2 – Boring Location Map
THE LAS POSAS OWNER LPV, LLC. Project No. 3649-SD Reduced Development Footprint Alternative – May 8, 2023 Vernal Pool Impact Minimization Plan Page 2
Selected References GeoTek, Inc. 2023, Reduced Pacific Specific Plan Project, Northwest Corner of Linda Vista, Drive & Los Posas Road, San Marcos, California, Project Number 3649-SD, dated December 5, 2023.
THE LAS POSAS OWNER LPV, LLC. Project No. 3649-SD Reduced Development Footprint Alternative – May 8, 2023 Vernal Pool Impact Minimization Plan Page 3 LEGEND APPROXIMATE LOCATION OF ALLUVIUMBORING & PERCOLATION TEST LOCATIONSLIMITS OF PROPERTY SANTIAGO FORMATION, CIRCLED WHERE BURIED1384 Poinsettia Avenue, Suite A Vista, California 92081 The Los Posas Owner LPV, LLC Reduced Development Footprint – Vernal Pool Impact Minimization Linda Vista Dr. & Las Posas RdSan Marcos, California Figure 2Boring Location Plan B-6 QalTsa
P-1B-6QalTsa
Tsa
P-2
P-2 PN: 3649-SDMay2024
REVISED PRELIMINARY Geotechnical Evaluation REVISED PRELIMINARY Geotechnical Evaluation
FOR
PACIFIC GPA/REZONE REDUCED PACIFIC SPECIFIC PLAN PROJECT Northwest Corner of Linda Vista Drive & Los Posas Road
SAN MARCOS, CALIFORNIA
PREPARED FOR
The Las Posas Owner LPV, LLC, a Delaware limited liability company 2235 Encinitas Boulevard, Suite 216
Encinitas, California 92024
PREPARED BY
GEOTEK, INC.
1384 POINSETTIA AVENUE, SUITE A
VISTA, CALIFORNIA 92081
PROJECT NO. 3649-SD PROJECT NO.
3649-SD
DECEMBER 5JANUARY 26, 2023
GEOTECHNICAL | ENVIRONMENTAL | MATERIALS
January 4, 2022
DecemberJanuary 526, 2023
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 Evaluation
Pacific GPA/Rezone Reduced Pacific Specific Plan Project Northwest Corner of Linda Vista Drive & Los Posas Road
San Marcos, California
Dear Mr. Waite:
We are pleased to provide here in the results of our preliminary g eotechnical evaluation for the subject property located in the city of San Marcos, California. This report presents the results of our evaluation and provides preliminary geotechnical recommendations for future earthwork, foundation design, and construction . In our opinion, the property appears feasible from a geotechnical viewpoint provided that the recommendations included herein are incorporated into the future design and construction phases of property development. The opportunity to be of service is sincerely 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 COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5,January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, 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 .......................................................................................................................... 54
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) ............................................................................................................ 65
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......................................................................................................... 7
4.4.3 Other Seismic Hazards ..................................................................................................................... 7
5. CONCLUSIONS AND RECOMMENDATIONS .................................................................................. 7
5.1 General ............................................................................................................................................ 7
5.2 EARTHWORK CONSIDERATIONS ................................................................................................... 8
5.2.1 General ............................................................................................................................................ 8
5.2.2 Property Clearing and Preparation ..................................................................................................... 8
5.2.3 Remedial Grading ............................................................................................................................. 8
5.2.4 Engineered Fill ................................................................................................................................ 98
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...................................................................................................................... 14
5.3.6 Seismic Design Parameters ............................................................................................................. 14
5.3.7 Soil Sulfate Content ........................................................................................................................ 15
5.3.8 Preliminary Pavement Design .......................................................................................................... 15
5.4 RETAINING WALL DESIGN AND CONSTRUCTION ........................................................................ 16
5.4.1 General Design Criteria ................................................................................................................... 16
5.4.2 Restrained Retaining Walls ............................................................................................................. 17
5.4.3 Wall Backfill and Drainage ............................................................................................................. 17
5.5 POST CONSTRUCTION CONSIDERATIONS ................................................................................... 18
5.5.1 Landscape Maintenance and Planting .............................................................................................. 18 THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5,January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, San Marcos, California Page ii
TABLE OF CONTENTS
5.5.2 Drainage .................................................................................................................................... 1918
5.6 PLAN REVIEW AND CONSTRUCTION OBSERVATIONS ................................................................. 19
6. LIMITATIONS ........................................................................................................................................ 2019
7. SELECTED REFERENCES ....................................................................................................................... 21
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 COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, San Marcos, California Page 1
1. PURPOSE AND SCOPE OF SERVICES
The purpose of this study was to evaluate the geotechnical 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 onsite 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 presents our findings of pertinent geotechnical conditions and geotechnical recommendations 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 southeast by Los Posas Road, to the northeast by La Mirada Drive, and to the northwest by Pacific Street. 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 above 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 COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, San Marcos, California Page 2
2.2 Future Development / Project Description
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 449229 residential units, including a mix of apartments, rowhomes, villas, and affordable flats on approximately 15.0913.257 acres of the 33.229-acre project site.
Proposed residential units would include a mix of apartments within a five -story podium building, three-story rowhomes , and three-story villas, and affordable flats within a four -story building. The project includes a total of 927234 parking spaces and 134,98540,876 square feet of common open space area. 6845 of the 449229 total units ( 1520% 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 a reas, and circulation improvements. The remaining approximately 17.9419.972 acres of the 33.2 29-acre project site would be preserved and restored as open space and habitat area. The proposed project would have a density of approximately 13.522.5 dwelling u nits per acre, including the open space and habitat area.
The project proposes a General Plan Amendment, Rezone, Specific Plan, Tentative Map, and Multi-Family Site Development Plan. The General Plan Amendment and Rezone would change the General Plan designation and Zoning from Industrial (I) to Specific Plan Area (SPA). The Specific Plan has been prepared with the intent to provide a comprehensive plan to ensure the efficient development of a new residential community. The Specific Plan serves as both a policy document and a regulatory document for the systematic implementation of the policies and goals of the General Plan. The Tentative Map presents specific lot configurations for the site. The Multi -Family Site Development Plan will configure the sit e for multi family dwelling units, street configuration, infrastructure, recreational open space, and private open space.
As part of the project, additional pedestrian connectivity would be provided along three of the adjacent street frontages. The project would provide a 6 -foot sidewalk and Class II buffered bike lane along the project’s frontage on Pacific Street; the proje ct would provide a 12-foot urban trail (shared use path) along the project’s frontage on Linda Vista Drive; and THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, San Marcos, California Page 3
the project would also provide a 12 -foot urban trail (shared use path) along the project’s frontage on La Mirada Drive. In addition to the proposed sidewalk and trail connections, the project would add a bus stop and shelter with a bus turnout along South Las Posas Road adjacent to the development area and would install a 4 -way traffic signal at the intersection of Linda Vista Drive and Pacific Street. Furthermore, the project would upsize approximately 1,458-feet of existing water pipe from 8 -inches to 12 -inches and would convert approximately 1,400 -feet of existing overhead power lines to underground along La Mirada.
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 significantly, additional geotechnical field exploration, laboratory testing and engineering analyses 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 consisted 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 biological constraints and omitted from this report. Several variations of proposed boring locations were presented to California Fish and Wildlife (CFW), however, CFW only authorized the locations presented on Figure 2. A representative from our firm visually logged the borings and collected soil samples for laboratory analysis. Approximate locations of exploration locations 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
THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, San Marcos, California Page 4
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 presoaked 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 allowing 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 to allow rates to stabilize . Results of the final percolation increment were used to calculate a n infiltration rate in inches per hour via the Porchet method.
For design of shallow infiltration basins, converting 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 bo ttom conditions of a shallow basin (infiltration). Therefore, the percolation data for boring s 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 infiltration 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 local variations in soil conditions. An appropriate factor of safety used to compute the design percolation r ate should be considered at the discretion of the design engineer and acceptance of the plan reviewer.
THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, San Marcos, California Page 5
3.2 Laboratory Testing
Laboratory testing was performed on bulk and relatively undisturbed soil samples collected during the field explorations. The purpose of the laboratory testing was to evaluate their physical and chemical properties for use in engineering design and analysis. Results of the laboratory testing program, along with a brief description and relevant information regarding testing procedures , are included in Appendix B.
4. GEOLOGIC AND SOILS CONDITIONS
4.1 Regional Setting
The subject property is located in the Peninsular Ranges geomorphic province. The Peninsular Ranges province is one of the largest geomorphic units in western North America. Basically, it extends roughly 975 miles from the north and northeasterly 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 Pacific 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 northwest -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 margin 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. No 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 encountered 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 end-dump piles from illegal dumping . These soils are not considered suitable for support of structural improvements but may be re-used as engineered fill if properly processed and placed.
THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5January 26, 2023
Pacific GPA/Rezone Reduced Pacific Specific Plan Project, San Marcos, California Page 6
4.2.2 Alluvium (Map Symbol Qal)
The most recent regional geologic map reviewed showed 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.
4.2.3 Tertiary Santiago Formation (Map Symbol Tsa)
The most recent ly dated regional geologic map showing 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 Santiago Formation appears to be near the surface across most of the property. As encountered 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 not 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 system. 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 THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
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situated within an “Alquist-Priolo” Earthquake Fault Zone or a Special Studies Zone ( Bryant and Hart, 2007). No faults transecting the property were identified on the readily available geologic maps reviewed. The nearest known active fault is the 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 relatively cohesionless soils. These soils may thereby acquire a high degree of mobility, which can lead to lateral movement, sliding, consolidation and settlement of loose sediments, sand 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 potential include soil type and grain size, relative density, groundwater level, confining pressures, and both intensity and duration of ground shaking. In general, materials that are susceptible to liquefaction are loose, saturated granular soils having low fines content under low confining pressures.
The liquefaction potential and seismic settlement potential 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 the 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 geotechn ical evaluations of the property are anticipated at future dates once more detailed development plans THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
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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 201 9 (or current) California Building Code (CBC), and recommendations contained in this report. The Grading Guidelines included in Appendix C outline general procedures and do not anticipate all specific situations. In the event of conflict, the recommendations presented in the text of this report should supersede those contained in Appendix C.
5.2.2 Property Clearing and Preparation
Property preparation should start with removal of deleterious materials and vegetation. These materials should be disposed of properly off property. Any existing underground improvements, utilities and trench backfill should also be removed or be further evaluated as part of future development operations.
5.2.3 Remedial Grading
Prior to placement of fill materials and in all structural areas the upper variable, potentially compressible materials should be removed. Removals should include all existing fill , colluvium/weathered bedrock materials and we anticipate that the removals will extend approximately 5 feet below existing grade and should also extend to at least 2 feet below the bottom of proposed footing s. 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 compacted 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.
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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 should have the proposed excavated materials to be used as engineered fill at this property approved by the soils engineer prior to placement.
Engineered fill materials should be moisture conditioned to at or above optimum moisture content and compacted in horizontal lifts not exceeding 8 inch in loose thickness to a minimum relative compaction of 90% as determined in accordance with laboratory t est 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 materials and alluvium. A bulking factor of 5 to 10 percent may be considered for the upper 3 feet of Santiago Formation bedrock requiring removal and re -compaction. Subsidence should not be 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.
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Trench excavations should conform to Cal -OSHA regulations. The contractor should have a competent person, per OSHA requirements, during construction to observe conditions and to make the appropriate recommendations.
Utility trench backfill should be compacted to at least 90% relative compaction of the maximum dry density as determined per ASTM D 1557. Under-slab trenches should also be compacted to specifications.
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 compaction device. Ponding or jetting of trench backfill is not recommended. If backfill soils 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 subsurface is not recommended from a geotechnical perspective. Stormwater quality control 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 not intended to supersede the design by the structural engineer. The preliminary recommendations presented below are based on an assumed maximum column load of 150 kips for the planned 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 encountered and as verified by laboratory testing, soils near subgrade are anticipate to exhibit a “medium” (51 ≤ EI ≤ 90) potential for expansion THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
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per ASTM D4829. Materials with “low” (21 ≤ EI ≤ 50) expansiveness may also be encountered at depth and could be placed as engineered fill soils 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 performed and final recommendations should be based on as-graded soil conditions.
*Code minimums per Table 1809.7 of the 2019 CBC should be complied with. **Effective Plasticity Index should be verified at the completion of the rough grading.
It should be noted that the above recommendations are based on soil support characteristics only. The structural engineer should design the slab 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 perimeter footings that meet the depth
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-Story – 18
Four and Five-Story – 24
One- and Two Story – 18
Three -Story- 24
Four and Five-Story – 30
Minimum Foundation Width
(Inches)*
One- and Two Story – 12
Three-Story- 15
Four and Five-Story – 18
One- and Two Story – 12
Three-Story – 18
Four and Five-Story – 24
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 16< PI<30
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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and width requirements in the table above. This value 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 allowable soil bearing pressure on bedrock should be determined once foundation loads and elevations are known.
• Based on our experience in the area, structural foundations 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.
• The passive earth pressure may preliminarily be computed as an equivalent fluid having a density of 220 psf per foot of depth, to a maximum 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 combining 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 inches deep, should be utilized across large entrances, however, the base of the grade beam should be at the same elevation as the bottom of the adjoining footings.
• We recommend that control joints be placed in two directions 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 placed 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 punctures (e.g. stake penetrations, tears, punctures from walking on the vapor retarder placed atop the underlying ag gregate layer, etc.). These occurrences should be limited as much as possible during construction. Thicker membranes are THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
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generally more resistant to accidental puncture that thinner ones. Products specifically designed for use as moisture/vapor retarders may also be more puncture resistant. Although the CBC specifies a 6 mil vapor retarder membrane, it is GeoTek’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 to provide a certain level of resistance to vapor and moisture transmission through the concrete, 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. T he selected elements should have suitable properties (i.e. thickness, composition, strength and permeability) to achieve the desired performance level.
Moisture retarders can reduce, but not eliminate, moisture vapor rise from the underlying soils up through the slab. Moisture retarder systems should be designed and constructed in accordance with applicable American Concrete Institute, 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 engineer, archite ct, 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) sh ould provide recommendations relative to the slab moisture and vapor retarder systems and for migration of potential adverse 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 consultants in general, do not practice in the area of mold prevention. If specific recommendations addressing potential mold is sues are desired, then a professional mold prevention consultant should be contacted.
5.3.4 Miscellaneous Foundation Recommendations
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• 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 placed in the slab -on-grade areas unless properly compacted and tested. The excavations 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 lateral 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 descending slope. The setback should be at least 7 feet and need not exceed 40 feet.
• 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 structures 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 Latitude and -117.1961 Longitude. Spectral accelerations (Ss and S1), for 0.2 and 1.0 second periods 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.
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SEISMIC PARAMETERS
Mapped 0.2 sec Period Spectral Acceleration, Ss 0.897g
Mapped 1.0 sec Period Spectral Acceleration, S1 0.331g
Coefficient for Site Class “C”, Fa 1.2
Coefficient for Site Class “C”, Fv 1.5
Maximum Considered Earthquake (MCER) Spectral
Response Acceleration for 0.2 Second, SMS 1.077g
Maximum Considered Earthquake (MCER) Spectral
Response Acceleration for 1.0 Second, SM1 0.496g
5% Damped Design Spectral Response
Acceleration Parameter at 0.2 Second, SDS 0.718g
5% Damped Design Spectral Response
Acceleration Parameter at 1 second, SD1 0.331g
Modified Peak Ground Acceleration (PGAM) 0.465g
Seismic Design Category D
5.3.7 Soil Sulfate Content
Nearby s ulfate 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.
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, actual 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 the completion of grading for street subgrade and the above values are subject to change based laboratory 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.
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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 Section 200 -2.2 and 200 -2.4 of the Green Book, respectively. Pavement base should be compacted 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 M arcos specifications, and under the observation and testing of GeoTek and a City Inspector where required. Jurisdictional minimum compaction 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 retaining walls are added at a later date, the recommendations presented herein may apply to typical masonry or concrete vertical retaining walls to a maximum height of 10 feet. Additional review and recommendations should be requested for higher walls.
Retaining wall foundations embedded a minimum of 18 inches into engineered fill or dense formational materials should be designed using a n allowable bearing capacity of 2500 psf. An increase of one -third may be applied when considering 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 pressure component should be reduced by one - third.
An equivalent fluid pressure approach may be used to 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.
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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 imported sand other approved materials with an SE> 30 and an EI <20 and should be provided throughout the active zone.
The above equivalent fluid weights do not include other 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-induced equivalent fluid pressure of 14.4 pcf should be considered, where required . This force can be assumed to act as a typical fluid pressure, resulting in a triangular pressure distribution . The 201 9 CBC only requires the additional earthquake induced lateral force be considered on retaining walls in excess of six (6) feet in height; however, the additional force may be 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.
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 approximately 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 “select” materials shall be placed within the active zone as defined by a 1:1 (H:V) p rojection from the back of the retaining wall footing up to the retained surface behind the wall. Presence of other materials might necessitate revision to the parameters provided and modification of wall designs.
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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. Waterproofing 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 equivalent, 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 necessary to sust ain 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 landscaping 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 should be taken when adding soil amendments to avoid excessive watering. Leaching as a method of soil prepar ation prior to planting is not recommended. An abatement program to control ground -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 extreme care shou ld be exercised with regard to the irrigation and drainage in these areas. Waterproofing of the foundation and/or subdrains may THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANYProject No. 3649-SD Project No. 3649-SD
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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 system 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, retaining wall/shoring plans and foundation plans be reviewed by this office prior to construction 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 implementation 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 materials 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.
If requested, a construction observation and compaction report can be provided by GeoTek, which can comply with the requirements of the governmental 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.
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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 should in no way be construed to encompass any areas beyond the specific area of proposed construction as indicated to us by the client. The scope is based on our understanding of the future development and the client’s needs, our proposal (Proposal No. P -0300620-SD) date d March 25, 20 20 and geotechnical engineering standards normally used on similar property in this region.
The materials observed on the pro perty 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 conditions may vary due to seasonal changes or other factors. GeoTek, Inc. assumes no responsibility 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. Observations 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.
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7. SELECTED REFERENCES
American Society of Civil Engineers (ASCE), 201 6, “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 Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake 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. ____, 20 20, “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 January 2023
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
Reduced Pacific Specific Plan Project
N-NW Corner of Linda Vista Dr. & Las Posas
San Marcos, California
PN: 3649-SD December 2023
Figure 2
Boring Location
Plan
B-6
Tsa
Qal
Tsa
Qal
Tsa
P-1
P-2
B-6
B-3
B-4
B-5
Not to Scale
APPENDIX A
EXPLORATORY BORING LOGS
AND
INFILTRATION WORKSHEETS
THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Project No. 3649-SD
Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5, January 26, 2023
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 typ ically driven into the ground 12 or 18 inches with a 140 - pound hammer free falling from a height of 30 inches. 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 materials 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 airtight 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)
APPENDIX B
RESULTS OF LABORATORY TESTING
THE LAS POSAS OWNER LPV, LLC, A DELAWARE LIMITED LIABILITY COMPANY Project No. 3649-SD Project No. 3649-SD
Reduced Pacific Specific Plan Project Revised Preliminary Geotechnical Evaluation Revised Preliminary Geotechnical Evaluation December 5January 26, 2023
Pacific GPA/Rezone, Reduced Pacific Specific Plan Project San Marcos, California Page B-1
SUMMARY OF LABORATORY TESTING
Identification and Classification
Soils were identified visually in general accordance 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 collected 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 Procedure 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
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