Agenda Item No. 3
CITY COUNCIL STAFF REPORT
TO: Honorable Mayor and City Council DATE: January 8, 2024 FROM: Matthew Bronson, City Manager
PREPARED BY: Steve Kahn, Interim Public Works Director
Gabriel Munoz-Morris, Senior Engineer
SUBJECT: Introduction and First Reading of an Ordinance Repealing and Replacing Chapter 1 (Sanitary Sewer System) of Article VII (Public Works) of the Grover Beach Municipal Code
RECOMMENDATION
Introduce and conduct the first reading, by title only, of an Ordinance repealing and replacing Chapter 1 (Sanitary Sewer System) of Article VII (Public Works) of the Grover Beach Municipal Code to update the City’s Sewer Ordinance and schedule the second reading and public hearing for the next regularly scheduled meeting.
BACKGROUND
The City’s current Sewer Ordinance was originally adopted in 1965 in conjunction with the establishment of the City’s original Sewer Assessment District No. 1 (District) that constructed most of the City’s sewer system. The District did not include any land south of Farroll Road as most of that land was privately owned at that time and had not yet been subdivided and developed.
Assessment District No. 1, along with Ordinance 72, sought to standardize requirements for sewer collection in the city and established a timeline for properties to connect to the City’s sewer collection system. Ordinance 72 also established regulations on the character of waste that could be discharged to the sewer collection system and were generally consistent with regulations adopted by the South San Luis Obispo County Sanitation District (SSLOCSD) that operates the sewage treatment plant where sewer from Grover Beach is treated. Since its adoption in 1965, Ordinance 72 has been amended several times as needed to ensure the City’s compliance with new regulations and requirements from SSLOCSD, and to regulate new additions and extensions of the City’s sewer collection system.
Between 2009 and 2020, the City made significant investments to construct sewer mains in the industrial areas south of Farroll Road that resulted in construction of 7,100 linear feet of new sewer main at a cost of $1.8 million. These investments were made at the Council’s direction to modernize and expand the City’s sewer infrastructure and reduce the risk of groundwater contamination from septic systems. However, few properties in this area have connected to the new sewer system and most properties are treating their own wastewater with private septic tank and leach field systems. Most of these private systems were constructed prior to the adoption of the State Water Resources Control Board’s Policy for Onsite Wastewater Treatment Systems and their condition and maintenance history is largely unknown. Standards for private treatment systems were far less stringent at the time these systems were constructed and there is greater potential for groundwater contamination now given the age and unknown condition and history of these systems. In a 1962 Investigation of Nitrates in Ground Water in the Grover Beach area (Attachment 6), the California Department of Water Resources highlighted percolation of domestic Staff Report: First Reading of Ordinance to Update Sewer Ordinance Page 2 January 8, 2024
sewage as of one two major sources of groundwater impairment for the local groundwater. This conclusion has been further confirmed through monitoring Nitrate levels in extracted groundwater through the City’s production wells over the last 60 years. This is a defined constituent element of potential groundwater contamination that the City considers a public health and safety issue.
Staff previously brought a proposed update to the existing Sewer Ordinance to the Council for first reading an introduction on May 8, 2023 and the Council held a public hearing on May 22, 2023. At the hearing, Council considered public comment in opposition to the update and asked that staff review issues presented before modifying the proposed ordinance for adoption. Staff modified the proposed ordinance update to allow for more time to connect to sewer after passage of the updated ordinance, clarify the need for property owners to continue to maintain their existing septic systems properly until time of connection to the sewer system, and clarify exemptions for residential properties that would have to install lift stations to connect to the sewer system. The Council considered a policy discussion of the proposed ordinance, which incorporated changes to address public comments from the May 22, 2023 meeting, on July 24, 2023 and provided direction to staff to return to Council for adoption of the ordinance without further changes.
Proposed Ordinance Updates-Time to Connect
Based on Council direction, this proposed update to the City’s sewer regulations would replace Ordinance 72 and incorporate the language from several other related ordinances and amendments into a single new ordinance. The City’s Master Fee Schedule would be included by reference instead of having fees included directly in the ordinance and the SSLOCSD regulations regarding character of waste would be adopted by reference. These changes allow fees and sewer discharge regulations to be updated without requiring additional updates to the sewer ordinance as frequently going forward. The only regulatory change proposed with this new ordinance is to establish a citywide requirement for connection to the City sewer system, with some exceptions discussed below, and to remove all references to Sewer Assessment District No. 1. Requiring this connection is consistent with Council direction at the July 24th, 2023, ordinance workshop. At that workshop, staff recommended establishing a two-year time period for all properties in Grover Beach to connect to City sewer when a property is located within 200- feet of a City sewer line. Since the workshop, several property owners have proactively sought to connect to City sewer rather than wait for an ordinance update with this requirement, and more continue to apply citing interest in connecting after discovering, due to the City’s workshop and notifications, that their property already had a lateral in the street to their property line. Staff now recommends modifying the two-year connection requirement to a three-year connection requirement in recognition that some property owners have expressed interest in connecting but have requested a slightly longer timeline to budget for the cost of doing so. It is estimated that 130 properties would be affected by this requirement that are currently not connected to sewer.
These three-year grace periods and distance to sewer requirements are consistent with the original requirements in Ordinance 72 which helps ensure continuity between current and past development requirements as the City establishes uniform requirements for the sewer system citywide. The proposed ordinance also retains the ability for the City Council to grant time extensions where special circumstances exist such as an extreme hardship.
Regional Water Quality Control Board Requirements
Throughout the process of drafting the ordinance update, staff have met with Regional Water Quality Control Board staff to discuss current and upcoming regulations as they relate to septic systems. The State Water Resources Control Board is in the process of updating its Onsite Wastewater Treatment System (OWTS) Policy which is enforced by the Regional Water Quality Control Boards (RWQCB) and governs the siting, design, operation, and maintenance of OWTS.
Staff Report: First Reading of Ordinance to Update Sewer Ordinance Page 3 January 8, 2024
The OWTS Policy establishes various tiers for OWTS and designates all existing OWTS as Tier 0 until they begin to fail. If an existing OWTS begins to fail it is automatically reclassified as a Tier 4 (OWTS Requiring Corrective Action) and must be immediately repaired to the standards applicable to a Tier 1 (Low-Risk New or Replacement OWTS). The standards required to repair or replace an existing OWTS to Tier 1 status would make the repair or replacement of most of the existing septic systems in Grover Beach impossible. Systems within 200-feet of City sewer would be required to connect per the California Plumbing Code while systems on properties more than 200-feet from City sewer would see elevated design and construction costs to meet various design requirements included in the OWTS Policy. RWQCB staff indicated that the OWTS policy has been drafted in a way that will ultimately result in the conversion of properties on septic to sewer in urbanized, higher-density jurisdictions like Grover Beach as those systems reach the end of their design life.
Table 1 in Section 7.8 of the OWTS Policy establishes requirements for allowable density per subdivision under Tier 1. For Grover Beach, the highest allowable density would be 2 acres per single family dwelling unit which is a much lower density than that of properties with existing septic systems. Section 8 of the OWTS establishes minimum design and construction standards for OWTS. This section establishes minimum depths to groundwater from the bottom of the OWTS dispersal system. For Grover Beach, a minimum depth of 5-8 feet would be typical which is very difficult to comply with in the industrial area where most of the remaining septic systems are.
Recent data from monitoring wells in the industrial area show that groundwater is located between
6.5 and 8.5 feet below ground surface which is almost entirely above this minimum depth to groundwater when factoring required cover above the dispersal system and the height of the system itself.
This section of the OWTS also establishes the requirement for all new onsite systems to have a replacement area equal to 100% of the system’s size set aside and available for future use which would severely limit usable space on any property proposing a new system. Dispersal systems and replacement areas are not permitted to be covered by an impermeable surface such as asphalt, concrete, or buildings. However, most of the properties in the City’s industrial area are nearly, if not completely, covered in impermeable materials meaning that all replacement or new OWTS would require removal of existing impermeable materials. There are additional standards in Section 8 of the OWTS Policy that govern the design and construction of new or replacement systems, but the points listed above would effectively make replacement of an existing system far more costly than connection to the City’s sewer system in instances where connection to the sewer system is available.
Costs of Connection
Property owners connecting to the City sewer would be required to pay sewer impact fees and the cost to construct their connection and abandon their septic tank system. Due to the varying nature of each property and the ability of each property owner to request various quotes from contractors, staff cannot provide an exact estimate for the total cost of connection to City sewer.
However, based recent connection projects, research into construction costs, and conversations with various contractors offering these services, staff estimates the average cost should generally be $15,000 to $20,000 for one property. This amount includes permits and impact fees paid at time of connection. For residential properties, the impact fees including both City impact fees and SSLOCSD impact fees range from approximately $4,100 to $5,100 depending on the size of their water meter. For commercial and industrial properties, the impact fees including both City impact fees and SSLOCSD impact fees range from approximately $5,300 to $8,900 depending on the size of their water meter. Most of these impact fees are SSLOCSD fees which are subject to change. The remaining costs include City permit fees (which are typically $1,000 or less) and Staff Report: First Reading of Ordinance to Update Sewer Ordinance Page 4 January 8, 2024
construction costs which comprise the bulk of the $15,000-20,000 average cost estimate per property. It would be each property owner’s responsibility to hire their own contractor to perform the septic tank abandonment and sewer connection work. Please see Attachment 4 for a breakdown of the expected costs to connect for a residential property with a ¾" water meter.
Residential Connection Exemptions
Most of the remaining properties not connected to the City’s sewer system are industrial and/or commercial properties, but some residential properties remain on septic as well. For residential properties, it is important to note that Sections 713.0 through 713.7 of the California Plumbing Code (Plumbing Code) establishes that no permit shall be issued for the installation, alteration, or repair of a private sewage disposal system, or part thereof, on a lot for which a connection with a public sewer is available. Within the Plumbing Code, availability of a public sewer system is defined as a sewer main located within 200-feet from the point of connection. An exemption to the connection requirement in the Plumbing Code is provided for residential properties with a properly functioning septic system when the connection to the City sewer cannot be accomplished via a gravity-fed connection. The draft ordinance consequently includes language referencing the Plumbing Code requirements to connect to City sewer and details the exemption for residential properties within 200-feet of City sewer that could not establish a gravity-fed sewer connection.
The exemption would be in effect until an alternate connection point became available that would allow for a gravity-fed connection. This exemption would eliminate a potentially increased cost of connection for residential property owners that are within 200-feet of City sewer but would need to install a sewage pumping station to connect to City sewer. While the Plumbing Code limits this exemption to single family residential properties, the draft ordinance expands this exemption to all residential properties. Commercial and industrial properties are excluded from this exemption in the Plumbing Code, but staff believes that all commercial and industrial properties in the City currently on septic and within 200-feet of a city sewer could establish a gravity-fed connection to City sewer.
Septic to Sewer Grant Funding
Through coordination with the RWQCB, staff expressed the City’s interest in finding ways to reduce the financial burden of sewer connection for property owners experiencing financial hardships. RWQCB staff indicated that there is funding in the State Revolving Fund (SRF) available for septic-to-sewer conversion projects for lower income areas. The City does not qualify for this funding, but specific sub-areas can be studied to determine if the median household income (MHI) in that area qualifies the area for grant funding.
Staff discussed each of the residential areas that are not currently connected to City sewer with RWQCB staff to determine if they would likely qualify for grant funding. RWQCB staff indicated that the area near Rose Court would be very unlikely to qualify as well as the properties in the northern portion of the city. The residential portion of the industrial area was highlighted by RWQCB staff as an area with a strong possibility of qualifying for grant funding. This area has traditionally had a lower MHI and has a high concentration of residential properties that are not currently connected to City sewer. In addition, there are two clusters of residential properties along Farroll Road that could potentially be connected to City sewer through a grant funded project.
These areas are depicted in Attachment 5.
To confirm eligibility, the City would have to fund an income survey to confirm MHI in these areas is consistent with grant funding requirements. The estimated cost of this income survey is $10,000 but that cost would be reimbursed to the City if the areas qualified for a grant funded project. The grant funds have no local match requirement currently and allow for an award of up to $125,000 Staff Report: First Reading of Ordinance to Update Sewer Ordinance Page 5 January 8, 2024
per connected property. This funding would cover needed sewer main extensions, construction of sewer laterals for each property, abandonment of existing septic systems, connection of onsite piping to the new sewer lateral, and payment of impact fees associated with connection to City sewer. This would effectively allow for connection of these residential properties at little to no cost to the property owners.
RWQCB staff have indicated that this grant funded project would likely take between 5-6 years from date of the income survey to completion of construction. The residential properties affected by this would be exempted from connection under the new ordinance because there is not currently a sewer main within 200-feet of their connection point. If this area is determined to be eligible, the grant funding would allow for the connection of approximately 26 residential properties at no cost to the City or the property owners while allowing the City to pursue sewer main extension projects in other areas to achieve connections where not currently possible. Staff will return at second reading and adoption of the draft ordinance with a request for direction from Council as to whether to pursue an income survey for the areas in Attachment 5.
Conclusion
Once adopted, staff will work to contact all properties that currently have City sewer available and inform them of the requirement to connect to City sewer within three years of adoption. Staff anticipates that most of these notices will be sent to properties in the industrial area which is defined as the area bounded by South 4th Street to the west, Farroll Road to the north, South 13th Street to the east, and the City’s southern jurisdictional boundary to the south. In the future if additional sewer main projects are planned, staff would contact affected property owners and advise them of the proposed project and connection requirements. At the July 24th workshop, Council provided direction to staff to finalize a Sewer Connection/Septic Tank Abandonment FAQ/Fact Sheet for property owners to reference if they had questions about the process. The document is finalized, and staff will post it on the City’s webpage when the new sewer ordinance is adopted. Staff also notified all affected property owners of the planned public hearing on January 22, 2024 for the adoption of the updated sewer ordinance.
FISCAL IMPACT
There is no City fiscal impact associated with this action. After connection of properties to City sewer, the City would receive Sewer Development Impact Fees and monthly sewer use payments as established by the Master Fee Schedule. However, this additional revenue would not be a substantial increase in Wastewater Enterprise Fund revenue and would come over time based on the connection timeframe established in the ordinance.
ALTERNATIVES
The Council has the following alternatives to consider:
1. Conduct the first reading, by title only, of an Ordinance to repeal and replace Chapter 1 (Sanitary Sewer System) of Article VII (Public Works) of the Grover Beach Municipal Code; or,
2. Provide staff with alternate direction.
Staff Report: First Reading of Ordinance to Update Sewer Ordinance Page 6 January 8, 2024
PUBLIC NOTIFICATION
The agenda was posted in accordance with the Brown Act.
Attachments
1. Ordinance No. 24-
2. Sewer-Septic Conversion FAQ/Fact Sheet
3. Map of Properties Currently on Septic
4. Septic to Sewer Cost Breakdown
5. Possible Grant Funded Project Areas
6. 1962 Investigation of Nitrates in Ground Water Report Attachment 1
ORDINANCE NO. 24-__
AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF GROVER BEACH, CALIFORNIA, REPEALING CHAPTER 1 OF ARTICLE VII AND ADOPTING A NEW CHAPTER 1, ARTICLE VII OF THE GROVER BEACH MUNICIPAL CODE WHEREAS, the City of Grover Beach is a General Law city organized pursuant to Article XI of the California Constitution; and
WHEREAS, pursuant to the authority granted the City by Article XI, Section 7 of the California Constitution, the City has the police power to adopt regulations designed to promote the public convenience or the general prosperity, as well as regulations designed to promote the public health, morals or public safety; and
NOW THEREFORE, BE IT HEREBY ORDAINED BY THE CITY COUNCIL OF THE CITY OF GROVER BEACH AS FOLLOWS:
PART 1. Chapter 1 of Article VII of the Grover Beach Municipal Code is hereby repealed in total:
PART 2. Chapter 1 of Article VII or the Grover Beach Municipal Code is hereby added as follows:
CHAPTER 1 - SANITARY SEWER SYSTEM
PART 1 - GENERAL PROVISIONS
Sec. 7100. Enabling Authority. This chapter is adopted pursuant to authority granted by Government Code Section 38900 that a city legislative body may construct, establish, and maintain drains and sewers.
The following Municipal Code sections shall remain in full force and effect except that all references language specific to fee amounts shall be repealed and replaced with “as set forth in the Master Fee Schedule as amended from time to time”:
Article II, Chapter 3, Section 2302
Article 111, Chapter 1, Section 3141
Article 111, Chapter 1, Section 3405 (A) & (E)
Article 111, Chapter 1, Section 3903
Article 111, Chapter 1, Section 3908
Article 111, Chapter 1, Section 3915
Article 111, Chapter 11, Section 3976
Article Ill, Chapter 11, Section 3979
Article 111, Chapter 12, Section 3990
Ordinance No. 24-__ Page 2
Article V, Chapter 2, Section 5203
Article V, Chapter 2, Section 5219
Article V, Chapter 2, Section 5220
Article V, Chapter 4, Section 5413 (B) & (H)
Article VII, Chapter 1, Section 7156
Article VII, Chapter 1, Section 7180 (A) - (N)
Article VII, Chapter 1, Section 7182
Article VII, Chapter 1, Section 7185
Article VII, Chapter 1, Section 7190
Article VII, Chapter 2, Section 7233
Article VIII, Chapter 2, Section 8202
Article VIII, Chapter 2, Section 8204
Article VIII, Chapter 2, Section 8205
Sec. 7111. Application. This chapter shall apply to all sewer facilities of the City of Grover Beach, including but not limited to, building sewers, sewer laterals, and sewer mains as defined in Part
2. PART 2 - DEFINITIONS
Sec. 7120. Definitions. (A) For the purpose of this chapter, unless it is plainly evident from the context that a different meaning is intended, the following terms used herein are defined as follows:
(1) Back-water Valve or Backflow Prevention Device: A device whose purpose is to prevent flow in a sewer in a direction opposite to that of the intended drainage; (2) Council: The City Council of the City of Grover Beach. (3) Building: Any structure used for human habitation, or a place of business, recreation, or other activity and containing sanitary facilities;
(4) Building Sewer: That portion of any sewer beginning at the plumbing or drainage outlet of any building, industrial facility, or preliminary treatment facility, and ending at the property line;
(5) Cesspool or Seepage Pit: An excavation in the ground which receives the discharge from a sewer for the purpose of allowing said discharge to percolate into the ground; (6) City: The City of Grover Beach, State of California; (7) City Engineer: Registered Civil Engineer appointed by the City Council of the City of Grover Beach to perform regular and/or special engineering services; (8) City's Representative: Any person legally authorized by the Council of the City of Grover Beach to represent the City in matters relating to the City’s sewer system; (9) Cleanout: A branch fitting installed in a sewer or other pipe for the purpose of providing access for cleaning;
Ordinance No. 24-__ Page 3
(10) County: County of San Luis Obispo, State of California; (11) Crown: The highest point of the inside surface of a sewer cross-section; (12) District, Sanitation District, or SSLOCSD: The South San Luis Obispo County Sanitation District;
(13) District’s Representative: Any person legally authorized by the Board of Directors of the South San Luis Obispo County Sanitation District to represent the District; (14) Engineering Standards and Specifications: The current edition of the Engineering Standards and Specifications of the City of Grover Beach. (15) Fixture: Any sink, tub, shower, toilet, or other facility connected by drain to the sewer:
(16) Garbage: Solid wastes from the preparation, cooking, and dispensing of food and from the handling, storage and sale of agricultural products; (17) Lot: Any piece or parcel of land, bounded, defined, or shown upon a plot or deed recorded in the office of the County Recorder of San Luis Obispo County, provided, however, that in the event any structure is located upon more than one parcel of land all under one ownership and as herein defined, the term "lot" shall include all such parcels of land. For purposes of land which is to be annexed to or served by the City, the term "lot" shall be defined as (1) a minimum size parcel or parcels into which said land can be subdivided or split as permitted by the local zoning regulations, or (2) the actual number of parcels into which said land is subdivided or split as evidenced by records filed with the County Recorder;
(18) Manhole: A structure for the purpose of providing access to a buried sewer; (19) Permit: Any written authorization required pursuant to this chapter; (20) Person: Any human being, individual, firm, company, partnership, association, corporation, government or agency;
(21) Privy: An excavation in the ground receiving or intended to receive human body wastes; (22) Public Sewer: That portion of a sewer lying within a public right-of-way or easement, including lateral sewers that are publicly maintained and sewer mains owned and maintained by, and subject to the jurisdiction of, the City; (23) pH. The logarithm of the reciprocal of the weight of hydrogen ions in grams per liter of solution;
(24) Septic Tank: A structure for treating sewage before disposal in a seepage pit or other leaching system;
(25) Sewage: Any water or fluid-carried wastes from residences, business buildings, public buildings, institutions, and industrial facilities;
(26) Sewage Works or Sewerage: All facilities for collecting, pumping, treating, and disposing of sewage;
(27) Sewer: A pipe or conduit for carrying sewage;
(28) Sewer Lateral: The portion of a sewer lying within a public right-of-way or easement and connecting a building sewer to a sewer main. Unless otherwise approved by the City Engineer or publicly maintained, sewer laterals are privately owned and maintained, including the cut-in or wye connection to the sewer main ; (29) Sewer Main: Those sewers, excluding sewer laterals, whose main purpose is to accept sewerage from laterals and convey it to the treatment plant; (30) Shall and May: Shall is mandatory; may is permissive; (31) Trunk Sewer: The same as sewer main.
Ordinance No. 24-__ Page 4
PART 3 - HOUSE SEWERS
GENERAL REGULATIONS AND MATERIALS
Sec. 7130. Separate Connection for Each Building. Every building in which plumbing fixtures are installed shall be separately and independently connected with the public sewer except as provided herein.
Sec. 7131. Exception; Dwelling in Rear. Where a dwelling is on the rear of a lot, on the front of which is another building and the total street frontage of the said lot does not exceed sixty (60) feet, and is under one ownership, a separate sewer connection will not be required.
Sec. 7132. Exception; Accessory Dwelling Unit. Where an accessory dwelling unit is located on a lot on which there is also a primary residence, and is under one ownership, a separate sewer connection will not be required.
Sec. 7133. Exception; Appurtenant Buildings. Service buildings, such as a garage, servants' quarter, powerhouse, or other like buildings where required as an adjunct to and to be used in connection with a residence, public building, or commercial plant, may be connected to the house sewer serving the main building.
Sec. 7134. Materials. Building sewer lines may be of any materials allowed by the California Plumbing Code currently in effect and approved by the Building Inspector. Conformance with ASTM standards for the materials used shall apply.
Sec. 7135. Building Sewers; Size and Specifications. House sewers shall be not less than four (4) inches in diameter and shall have a continuous and even fall of not less than one-quarter (1/4) of an inch to the foot, except where solid rock or other unusual condition is encountered, then, with the approval of the City Engineer, the requirements for an even grade may be altered to best suit the given condition and to provide the best fall available under the circumstances.
Sec. 7135.1. Building Sewers; Backflow Prevention Devices. Building sewers must be constructed in accordance to the requirements of the California Plumbing Code with regard to backflow prevention devices. The installation of the backflow prevention device shall be at the sole cost and expense of the property owner and maintenance of the device shall be the sole obligation of the property owner or the owner’s successor in interest.
Sec. 7136. Protection of Sewer Laterals Where Substandard Depth. That portion of the sewer lateral from the curb line to the property line which has less than three (3) feet of cover between the top of the pipe and the curb or the top of the ground shall be protected as required by the City Engineer.
Sec. 7137. Old Building Sewers and Sewer Laterals, Use of. Old building sewers and sewer laterals may be used in connection with new plumbing work when, upon examination, they are found to conform to the requirements governing new building sewers and new sewer laterals as provided in this ordinance. Examination of the existing sewer lateral shall be completed prior to issuance of any permit resulting in re-use of the lateral.
Sec. 7138. Permits; When Required. A permit will not be required for the purposes of removing stoppages or performing repairs in any building sewer. Use of the public right-of-Way to repair a sewer lateral shall require an approved Encroachment Permit from the Department of Public Works of the City of Grover Beach
Ordinance No. 24-__ Page 5
Sec. 7139. Building Courts; Common Pipe. Building sewers from a building court (serving four units or more) may be connected to a sewer main through a common pipe and sewer lateral, provided that such common pipe and sewer lateral be of adequate size, as determined by the City Engineer, but must be at least 6 inches in diameter. The common pipe and sewer lateral shall be run in as direct a line to the sewer main as possible and a manhole shall be provided at its junction with the existing sewer main. A riser of the requirements and specifications of the City shall be placed within two and one-half (2-1/2) feet of the point of connection of the house sewer located the farthest from the public sewer. Such building sewers connecting to the common pipe shall be laid under the same requirements as if they were to connect directly to a sewer main.
Sec. 7140. New Septic Tanks, Etc.; Repairs to Old. Where a public sewer is located within a distance of two hundred (200) feet (measured along streets, alleys, avenues, or public rights-ofway upon which the property abuts), from point of connection, no new or replacement septic tank or leach line, leach field or sewer wells shall be constructed. Said properties shall connect to the public sewer and the existing septic tank or well shall be abandoned and removed or filled to the satisfaction of the City Engineer and Community Development Director. An exemption, per the California Plumbing Code, shall be made for residential properties where a public sewer is located within two-hundred feet but connection to the public sewer cannot be accomplished via a gravityfed connection. This exemption shall extend until an alternative point of connection to the public sewer becomes available that allows for a gravity-fed connection. All property owners whose property is currently serviced by a septic tank or sewer well shall take every action necessary to ensure the continued proper functioning of the existing system, regardless of the proximity of a public sewer, and provide for inspections by The Public Works Director, or their designee, upon written request.
Sec. 7140.1 Grease Traps, Catch Basins, Sumps, Etc. To prevent sand, grease, soil or other objectionable matter entering the sewerage system, restaurants and public places serving food shall be provided with grease traps, and public and private garage floor drains and public wash racks shall be provided with catch basins or sumps of a design approved by the City Engineer and in conformance with the California Plumbing Code. Garage and oiling pits shall not be connected to any sewerage system.
Sec. 7141. Time for Connection to Sewerage System. Where a public sewer is located within a distance of two hundred (200) feet (measured along streets, alleys, avenues, or public Right-ofWays upon which the property abuts) and except as otherwise provided in this Chapter, every building now or hereafter situated within the City of Grover Beach in which plumbing fixtures are now or hereafter installed shall be separately and independently connected to the city sewerage system by the property owner within three years of adoption of this Ordinance by the City Council.
Said property owners shall make application for the sewer connection pursuant to Section 7157.
All buildings within the City of Grover Beach which are required by this section to be connected to the city sewerage collection system shall be subject to monthly sewer fees commencing on the date of connection to the sewerage collection system. Upon completion of the required connection to the city sewerage system, any existing septic tank or well shall be abandoned and removed or filled, according to the direction of and to the satisfaction of the City Engineer and the Community Development Director. Upon written application by the property owner, and on a showing of good cause therefore, the City Council may grant an extension of time to connect a building to the city sewerage collection system of up to two additional years. Such extension of time may be granted only upon condition that the applicant pay monthly payments toward the required sewer impact Ordinance No. 24-__ Page 6
fee amount divided into equal installments equivalent to the number of months extension granted by the Council. Failure to comply with any of the provisions of this section shall be deemed to be a misdemeanor.
Sec. 7141.1. Public Nuisance. Notwithstanding any other provisions of the City of Grover Beach Municipal Code, noncompliance with either Section 7140 or 7141 or the further maintenance or use of cesspools, septic tanks, or other means of sewage disposal in the City of Grover Beach inconsistent with the requirements of this Chapter, by any person, except as permitted pursuant to this Chapter, is a public nuisance. The occupancy of any building from which sewage is discharged in violation of this Chapter is a public nuisance, and an action may be brought to enjoin any person from occupying any such building.
PART 4 - GENERAL RULES
Sec. 7150. Engineering Standards and Specifications. The City may, by resolution, update its Engineering Standards and Specifications for the construction of sewerage works, and such standards and specifications, when adopted, shall become part of this ordinance.
Sec. 7151. Private Sewage Systems Unlawful. No person shall connect to, use, provide, or maintain any system for the handling or treating of sewage or other liquid wastes within the boundaries of the City that was not in existence and use at the time of adoption of this Ordinance, except as herein provided, or upon authorization given by resolution of the City Council.
Sec. 7152. Protection from Damage. No unauthorized person shall break, damage, deface, uncover, or tamper with any structure, appurtenance, equipment or other property which is a part of the city sewage system. An approved Encroachment Permit shall be required prior to commencement of any work on a sewer lateral, sewer main, or any sewer appurtenances within the public Right-of-Way. No manhole shall be covered or made inaccessible. If required by changes in surface grade made necessary because of property development, and/or subdivisions, manholes shall be reconstructed by the developer and/or subdivider to conform to this requirement.
Sec. 7153. Investigation Powers. City representatives shall carry evidence establishing their position as an authorized representative of the City and, upon presentation and exhibiting these proper credentials and identification, shall be permitted to enter in and upon all buildings and premises within the City for the purposes of inspection, observation, measurement, sampling, testing, or otherwise performing such duties as may be necessary in carrying out the provisions of this chapter. A denial of a City Representative access to a building or premise for purposes of performing such duties, shall be submitted to the City Attorney’s Office for acquisition of a court ordered inspection warrant.
Sec. 7154. Correction of Violation. Any person found to be in violation of any provision of this chapter shall be served by a representative of the City with written notice stating the nature of the violation and providing a reasonable time limit for the correction thereof. Said time limit shall be not less than two (2) or more than seven (7) working days, unless otherwise indicated in this chapter and/or the City Engineer determines otherwise. Such person shall permanently and completely correct the violation within the period allowed.
Ordinance No. 24-__ Page 7
Sec. 7155. Liability for Damages for Violation. Any person violating a provision of this chapter shall be liable for all damages resulting from such violation, or which arise from actions taken in the correction thereof.
Sec. 7156. Relief. Any person who by reason of special circumstances, believes that the application of any portion of this chapter as to them is unjust or inequitable may make written application to the City Council for relief. Said application shall set forth all of the special facts and circumstances and shall request the specific relief or modification desired. The Council, upon receipt of such application and after such investigation as deemed necessary, may take action to grant such relief or modification as it finds necessary. The Council, on its own motion and without an application, may, when special circumstances make the application of this chapter a hardship or unjust or inequitable, modify or suspend such portion of this chapter for the period during which the special circumstances exist. An application for relief under this section shall be in writing and shall be accompanied by a filing fee as set forth in the Master Fee Schedule and amended from time to time.
Sec. 7157. Permit and Fees Required Before Work Done. No sewer connected or to be connected to the City's sewerage system shall be installed, altered, or repaired until the appropriate permits for the work are obtained from the City and all required fees have been paid.
Sec. 7158. Use of Existing Sewer. Before a permit shall be issued for a sewer connection in any areas within the City, for which a property shall use any existing sewerage facilities of the City for which such property shall not have made full payment of its share of the cost thereof, the owner or applicant shall pay to the City a sum of money for such privilege to be computed by the City.
Sec. 7159. Permit Fees. Permit fees for construction, repair, or maintenance of private sewerage works shall be as set forth in the Master Fee Schedule and amended from time to time.
PART 5 - MAIN EXTENSIONS
Sec. 7160. Main Extensions to New Customers. Mains extended to serve new customers shall be subject to all of the provisions of this chapter. No main extension will be made by the City except on an approved dedicated street, alley, area where the City has obtained a recorded easement.
Sec. 7161. Cost of Main Extensions. The cost of main extensions, other than to subdivisions, may be pro-rated against all lots or property that may ultimately be benefited by connection to the sewer system.
Sec. 7162. Main Extensions to Subdivisions. Where sewer main extensions are required for subdivisions, it will be the responsibility of the owner or subdivider to pay the cost for complete installation of all sewer facilities required within the subdivision and for extension of sewer mains from the subdivision to the nearest existing main of adequate capacity for the area to be served.
Such sewer mains and sewer facilities shall be subject to all the requirements of the City. Upon official acceptance by the City, the City shall assume full ownership, maintenance and control of such mains and sewer facilities.
Ordinance No. 24-__ Page 8
PART 6 - STANDARDS AND REGULATIONS FOR QUALITY OF SEWER DISCHARGE Sec. 7170. No Discharge of Storm Waters, Etc. Into Sewers. It is unlawful for any person to discharge or cause to be discharged any storm water, surface water, ground water, roof runoff, subsurface drainage, cooling water or unpolluted industrial process waters into any sanitary sewer, except as is herein specifically provided.
Sec. 7171. Storm Sewers, Etc. Storm water and all unpolluted drainage shall be discharged to such sewers as are specifically designated as storm sewers, or to a natural outlet approved by the City Engineer and in conformance with all applicable state and federal laws. Industrial cooling water or unpolluted process waters may be discharged, upon approval of the City Engineer, to a storm sewer or natural outlet.
Sec. 7172. Pretreatment and Prohibited Waste. Except as hereinafter provided, no person shall discharge or cause to be discharged any waters or wastes into any public sewers that are prohibited by the SSLOCSD Ordinance 1994-1, or any subsequent revision currently in effect.
Sec. 7173. Grease, Oil and Sand Interceptors. Grease, oil and sand interceptors shall be provided when required by the California Plumbing Code, the Southern San Luis Obispo County Sanitation District (SSLOCSD) Fats, Oils, and Grease (FOG) Ordinance currently in effect, and when, in the opinion of the City Engineer, they are necessary for the proper handling of liquid wastes containing grease in excessive amounts, or any flammable wastes, sand, or other harmful ingredients; except that such interceptors shall not be required for private living quarters or dwelling units used solely for human habitation. All interceptors shall be of a type and capacity approved by the City Engineer in accordance with the California Plumbing Code and the SSLOCSD FOG Ordinance, and shall be located so as to be readily and easily accessible for cleaning and inspection. Upon change in ownership of the property, change in property use or change in ownership of property use on which an interceptor is installed, the property owner shall coordinate with the City Representative to perform an inspection of the interceptor and ensure it is compliant with current requirements of the California Plumbing Code and the SSLOCSD FOG Ordinance. Any interceptor found to be out of compliance with the requirements of the California Plumbing Code and/or the SSLOCSD FOG Ordinance shall be modified to comply with current requirements at the property owner’s expense. Food Service Establishments (FSEs) are required to enroll in the City’s Fats, Oils, and Grease Control Program and are subject to the regulatory requirements in this chapter and the SSLOCSD FOG Ordinance. Enrollment is the responsibility of the FSE owner and failure to enroll may result in citation.
Sec. 7173.1 Same; Construction. Grease and oil interceptors shall be constructed of impervious materials capable of withstanding abrupt and extreme changes in temperature. They shall be of substantial construction, water-tight, and equipped with easily removable covers which, when bolted in place, shall be gas-tight and water-tight. Grease and oil interceptors shall be constructed in conformance with the requirements of the California Plumbing Code and the SSLOCSD FOG Ordinance.
Sec. 7173.2. Same; Maintenance. Where installed, all grease, oil and sand interceptors shall be maintained by the owner, at their expense, in continuously efficient operation at all times.
Ordinance No. 24-__ Page 9
Sec. 7174. Right to Regulate Water and Wastes and Require Preliminary Treatment, Etc. (A)The admission into the public sewers of any waters or wastes having an average daily flow greater than two (2%) percent of the average daily sewage flow of the City of Grover City, or exceeding the limits established by the SSLOCSD Ordinance 1994-1, or any subsequent revision currently in effect shall be subject to the review and approval of the City Engineer.
(B) Where necessary, in the opinion of the City Engineer, the owner shall provide, at their expense, such preliminary treatment as may be necessary to reduce the nature and constituents of the discharge to comply with Section 7172 or control the quantities and rates of discharge of such waters or wastes.
(C) Plans, specifications, and any other pertinent information relating to proposed preliminary treatment facilities shall be submitted for the approval of the City Engineer and of the Regional Water Quality Control Board of the State of California, and no construction of such facilities shall be commenced until said approvals are obtained in writing.
Sec. 7174.1 FOG Control Program Correction of Violation. Any person, FSE, or property found to be in violation of the requirements of this chapter and/or the SSLOCSD FOG Ordinance shall be served by a representative of the City with written notice stating the nature of the violation and providing a time limit for the correction thereof per the requirements of Section 6 of the SSLOCSD FOG Ordinance.
Sec. 7175. Preliminary Treatment Facilities. Where preliminary treatment facilities are provided for any waters or wastes, they shall be maintained continuously in satisfactory and effective operation, by the owner, at their expense.
Sec. 7176. Installation of Control Manholes. When required by the City Engineer, the owner of any property served by a building sewer carrying industrial wastes shall install a suitable control manhole in the building sewer to facilitate observation, sampling and measurements of the wastes.
Such manhole, when required, shall be accessible and safely located, and shall be constructed in accordance with plans approved by the City Engineer. The manhole shall be installed by the owner at their expense and shall be maintained by the owner so as to be safe and accessible at all times.
Sec. 7177. Measurements, Tests and Analyses. All measurements, tests, and analyses of the characteristics of waters and wastes to which reference is made in Sections 7172 and 7174, shall be determined in accordance with "Standards Methods for the Examination of Water and Sewage," published by American Waterworks Association, and shall be determined at the control manhole provided for in Section 7176, or upon suitable samples taken at said control manhole.
In the event that no special manhole has been required, the control manhole shall be considered to be the nearest downstream manhole in the public sewer to the point at which the building sewer is connected.
Sec. 7178. Special Agreements with Industrial Concerns. No statement contained in this chapter shall be construed as preventing any special agreement or arrangement between the City and any industrial concern whereby an industrial waste of unusual strength or character may be accepted by the City for treatment, subject to payment therefor by the industrial concern.
Ordinance No. 24-__ Page 10
PART 7 - SEWER SERVICE CHARGES
Sec. 7180. Sewer Rental Charge. Every person whose premises in the City are served by a connection to the sewerage collection system of the City, whereby the sewerage or industrial wastes, or both, are disposed of by the City to the South San Luis Obispo County Sanitation District sewerage treatment plant, or otherwise, shall pay a sewer rental charge as set forth in the Master Fee Schedule as amended from time to time.
Sec. 7181. Same; Service Outside City. Any connection to the City’s sewerage collection system outside of the City limits shall be charged at double the rate charged within the City, or such other rate as the City Council may determine.
Sec. 7182. Same; Quantity Rates. All users other than single family residences and schools shall be entitled to three thousand (3,000) cubic feet of sewage for the minimum charge. Any excess over the minimum amount shall be charged at the rate as set forth in the Master Fee Schedule and amended from time to time. Such quantities of sewage shall be determined by the City, based upon the percentage of water used which is deposited in said sewer facility. Any occupant who may disagree with the City's determinations may, at the occupant's own expense, install private measuring devices in accordance with specifications approved by the City.
Sec. 7183. Vacancies. In case a residence or place of business becomes vacant, the minimum sewer charge shall be collected.
Sec. 7184. Collections. All charges for such sewage service shall be paid at the same time as water charges are paid to the City and shall be billed upon the same utility bill sent to the user and both amounts must be paid or the City may, in addition to other remedies, shut off the water service.
Sec. 7185. Penalties. Any person failing to pay the sewer service charge when due, and if the water service has been disconnected, shall pay the sum as set forth in the Master Fee Schedule and amended from time to time.
Sec. 7186. Application of Revenue. Revenue derived by the City under the provisions of this chapter shall be used for the operation, acquisition, construction, reconstruction, and maintenance of the sanitary sewer system and shall be applied to the retirement of any bonded indebtedness which was incurred to building the sanitary sewer system.
PART 8 -- SEWER FACILITY FEES
Sec. 7190. Facility Fees. Facility fees shall be charged as set forth in the Master Fee Schedule and amended from time to time.
Sec. 7191. Payment for Connection. The permit for water and sewer connections shall be made at such time as any building permit is issued.
PART 2. If any section, subsection, subdivision, paragraph, sentence, clause, or phrase of this Ordinance or any part thereof is for any reason held to be unconstitutional, such decision shall not affect the validity of the remaining portion of this Ordinance or any part thereof. The City Council hereby declares that it would have passed each section, subsection, subdivision, paragraph, sentence, clause, or phrase thereof, irrespective of the fact that any one or more Ordinance No. 24-__ Page 11
sections, subsections, subdivisions, paragraphs, sentences, clauses, or phrases be declared unconstitutional.
PART 3. This Ordinance shall become effective at 12:01 a.m. on the 31st day after the date of its adoption, and within fifteen (15) days after its adoption, it shall be published once, together with the names of the Council Members voting thereon, in a newspaper of general circulation within the City.
INTRODUCED at a regular meeting of the City Council held on January 8, 2024, and PASSED, APPROVED, and ADOPTED by the City Council on January 22, 2024, on the following roll call vote to wit:
AYES: Council Members –
NOES: Council Members –
ABSENT: Council Members –
ABSTAIN: Council Members –
RECUSED: Council Members –
KAREN BRIGHT, MAYOR
Attest:
WENDI B. SIMS, CITY CLERK
Approved as to Form:
DAVID P. HALE, CITY ATTORNEY
C i t y o f G r o v e r B e a c h
DEPARTMENT OF PUBLIC WORKS
154 S. 8th Street ❖Grover Beach, CA 93433 ❖ (805) 473-4530 ❖[email protected] Visit our website at www.groverbeach.org
SEPTIC TANK ABANDONMENT – CONNECTION TO CITY SEWER
FREQUENTLY ASKED QUESTIONS | FACT SHEET
Looking to abandon your septic tank and connect to the City’s wastewater collection system? Please review this form for useful information about this process.
Definitions:
1. Septic Tank, Onsite Wastewater Treatment System (OWTS), or Private Sewage Disposal System (PSDS): A privately owned and maintained underground tank in which sewage is collected and allowed to decompose before draining by means of a leaching field.
2. City Sewer, Public Sewer, Wastewater Collection System: The network of publicly owned and maintained sewer main lines throughout the City of Grover Beach that convey wastewater flows to the South Sal Luis Obispo County Sanitation District collection system and treatment plant in Oceano.
3. Sewer Lateral: The privately owned and maintained sewer line that connects a building on private property to the City’s wastewater collection system. Sewer laterals are maintained by the property owner from the City’s mainline to the building they serve. This includes the portion of the lateral located in the public Right-of-Way.
Frequently Asked Questions (and Answers):
Q: Which properties are required to connect to City sewer? A: All properties with a City sewer line within 200-feet (measured from property line) are required to connect to City sewer immediately in accordance with the City’s Sewer Ordinance.
If a property does not currently have a City sewer within 200-feet, they will be required to connect once a City sewer becomes available within 200’.
Q: Are there exemptions for properties within 200-feet of a City sewer? A: Yes, any residential property that currently has a City sewer within 200-feet but would be required to install a private wastewater pump station to connect to the City sewer system is exempted from immediate connection. These residential properties must connect to City sewer when: 1. Their existing septic system fails or 2. An alternative point of connection to the City’s sewer main becomes available that would not require installation of a private wastewater pump station. This exemption does not extend to commercial and/or industrial properties.
Q: My property is on septic, but the septic system has failed. I do not want to connect to City sewer and wish to repair or replace the existing septic system. What do I have to do? A: Any property that must repair or replace the existing septic system must comply with the requirements of the most recent edition of the California Plumbing Code and the State Water Resource Control Board’s OWTS Policy. If the system cannot be repaired or replaced in compliance with those regulations, connection the City sewer will be required.
Q: My property is on septic but there is a sewer line in the street, and I want to connect to it. What permits do I need?
A: You will need a plumbing permit for the septic tank abandonment. If your property does not have a lateral built to the property line, you will also need an encroachment permit for the work Attachment 2
C i t y o f G r o v e r B e a c h
DEPARTMENT OF PUBLIC WORKS
154 S. 8th Street ❖Grover Beach, CA 93433 ❖ (805) 473-4530 ❖[email protected] Visit our website at www.groverbeach.org
in the public Right-of-Way. The plumbing permit is issued by the Community Development Department and the encroachment permit is issued by the Public Works Department.
Q: How do I find out if my property has an existing lateral built to my property line or if there is an existing connection at the sewer main that I can use for my connection? A: Contact the Public Works Department at [email protected] or (805) 473-4530 for property-specific information about an available lateral or mainline connection.
Q: What fees do I have to pay to connect to City sewer? A: When pulling your permits, you will be required to pay one-time sewer impact fees. There are two main fees: a City wastewater impact fee and a Sanitation District fee. For a residential property with an existing ¾” water meter, the City impact fee is approximately $1,700 and the Sanitation District fee is approximately $2,500. In addition to impact fees, you will need a plumbing permit issued by the Community Development Department for this work. The fees and permit costs change from time to time, and you are encouraged to contact the Community Development Department for an estimate for your specific property. All City fees can be found in the Master Fee Schedule.
Q: Are there recurring charges that I have to pay once I am connected to City sewer? A: Your bi-monthly utility bill will include sewer charges once you connect to City sewer. These charges depend on several property-specific characteristics but a property with a $100 bimonthly utility bill before City sewer charges typically sees an increase of about $50-60 due to sewer charges. These charges include both City monthly charges and Sanitation District monthly charges. You are encouraged to contact the Utility Billing Department for a more detailed estimate for your property’s monthly sewer charges. All City fees can be found in the Master Fee Schedule.
Q: Do I have to hire my own contractor to abandon my septic system and connect to City Sewer? A: Yes, it is your responsibility as the property owner to hire an appropriately licensed and insured contractor to perform the septic abandonment and sewer connection work for your property. The City does not perform this work for private property owners. The cost of this work varies due to property-specific conditions but is generally up to $15,000.
Q: What City inspections are required for my septic abandonment and sewer connection project? A: The City’s building inspector will inspect the abandonment of the existing septic system and the Public Works inspector will inspect the connection to either the existing lateral or the City’s mainline. Building inspection requests can be called in at (805) 473-4527 and Public Works inspections can be called in at (805) 473-4534 at least 48-hours prior to the requested inspection date/time.
Q: I have additional questions about my septic system and/or connection to City’s sewer. What do I do?
A: Please contact the Public Works Department at [email protected] or (805) 473-4530. Depending on your questions, you may also need to speak with the Community Development Department or Utility Billing Department
Attachment 3
$1,700.00
$2,500.00
$1,000.00
$14,800.00
Septic to Sewer Cost Estimate Breakdown
Residential 3/4" Meter
Total Estimated Cost $20,000
City Impact Fees Sanitation District Impact Fees Permits Construction Attachment 4
Attachment 5
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STATE OF CALIFORNIA
THE RESOURCES AGENCY OF CALIFORNIA
DE.EA.RIMENT OF WATER RESOURCF.S
INVESTIGATION OF NITRA.TF.S
ll GROUND WATER
GROVER CITY
SAN WIS OBISPO COUNTY
A Report to
Central. Coastal. Re~ Water Pollution Control Board
(No. 3)
(Project No. 4103-054)
April 1962
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Attachment 6
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TABLE OF CONTENTS I
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l OF TRANSMITl'AL . . . . . . . . • . . . • . . . . • . . . . 111·, >WLEDGMENT . • . . . . . . . . . . . • • . . . • • . . . . . iv CZATION . . . . . . • . . . . . . . • . . • . • • . • • • • V :i.., •.
INTRODUCTION . • . . . . . • • . . 1
>rization . . . • . • . • • . . . . • • • . • . • • • . . • . 1 ,e and Scope . . . . . • . . . . . . . . . • . . • • . . . • 2 0f Investigation . • • . • . . . . . . • . . • . • . . • . ~ . 3
;
GROUND WATER GEOLOO Y AND MOVEMENT • • • . • . 4
WATER QUALITY . . • . • . . . . . . 6
FOSSIBLE SOURCES OF NITRATES IN GROUND WATER • . . 7
mta.ry Rocks . . . . . . . • . . • . . . • • . . • • . . . • ., 8 stic Sewage . . . . . . • . . . • • . . . • . • . . . . . . 9 ~izers . . . . . . . • . • • . . • • . . • • • . . . . . • . 10
WATER WELL CONSTRUCTION PRACTICES THAT
MAY ALLEVIATE NITRATE IMPAIRMENT . . • . . . ll:
SUMMARY OF FINDINGS . . . . . . . . . 14
RECOMMENDATIONS . . . . . . • • • • 14
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No,
No.
ix
TABLES
SUmmary of Well Construction Practices •••••••••
PIATF.S
Area of Investigation •••••••••••••••••
Geologic Sections A - A' and B - B' ••••••••••
Geologic Sections C - C' and D - D 1 • . . . . . . . .
Lines of Equal Elevation of Ground Water, Spring 1960 •• Nitrate Concentrations in Ground Water, Spring 1961
Nitrate Concentration vs. Time . . . . . . • • . . .
Nitrate Concentration va. Time . . . . . . . . . . . . .
APPENDlXES
J-U,neral Analyses of Surface Waters in the Vicinity
of Grover City
Mineral Analyses of Ground waters iD the Vicinity of
Grover City
Mineral Analyses of Se-.rage .Effluent, Arrcyo Grande
Treatment Plant
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• EDMUND G. BROWN
Gov~RNOR :: ~ 908 s . 8ROADWAV , Los ANGELli:5 , CALIF.
TELEPHOHl!h MA 0~4107
STATE OF CALIFORNIA ADDRESS REPLY TO
irpartmrut nf Dltatrr 1Rranurrra P . o. Box 6!598, LOS ANGELES D S , CALIP',
LOS ANGELES
April 30, 1962
ral Coastal Regional water
~uution Control Board (No. 3)
~ Garden Street
Luis Obispo, California
;ention: Mr. Raymond Walsh
Executive Officer
SUbject: Investigation of Nitrates in Ground Water,
Grover City, San Luis Obispo County
ri:;lemen:
Transmitted herewith 1s a report on our studies of the nitrate . _lem in the ground water basin near Grover City, San Luis Obispo County. ~ investigation, authorized under :rnteragency Agreement No. 12--6 and pre-- -d as Project No. 4103-054, included a three-year ground water sampling ram and evaluation of other available hydrologic and geologic data to ~ermine the possible sources ot nitrates and their effects on the local ···nd water supplies.
The study indicates that two major sources of nitrogen are soonsible for the current degradation of the ground water quality, the ication of nitrogenous fertilizers to the agricultural lands overlying _ be.sin, and, to a lesser degree, the percolation of domestic sewage. ~h of these sources co.:r=.ribut~ organic nitrogen in forms other than ·ate or nitrite; however, oxidation and conversion do occur, to subseitly cause ground water impairment.
In view of the fact that these sources of nitrate can be dnated only by placing a considerable economic hardship on the local ea, it 1s recommended that both agricultural and urban users of ground ~er be advised of improved well drilling techniques end well construction ~ards. Compliance with recommended practices shoul.d result in -wtantially reduced nitrate concentrations in the ground water extracted.
Sincerely yours,
/k~ -/'8 _4~~· ~
Herbert A. Howlett, District Engineer
Southern District
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ACKNOWLEOOMENT
The Department of water Resources very gratefully acknowledges the le assistance given to it by the various contributing public agencies i:n.vate companies in San LUis Obispo County,; their cooperation has greatly tated the execution ot the investigation.
nu is made of the following:
City of Arroyo Grande Public Works
In this regard, special
E. C. Loomis and Son, Arroyo Grande
Farm Advisor, San Lu.is Obispo County
Farm Advisor, State of California
Grover City Water District
San Luis Obispo County Flood Control and
Water Conservation District
San Luis Obispo County Health Department
University of California, Davis, California
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STATE OF CALIFORNIA
THE RESOURCES AGENCY OF CALIFORNIA
DEPAR'IME!1T OF ;t'IATER RESOURCES
ErMUND G. BROWN, Governor
ILLIAM E. WARNE, Administrator, The Resources Agency of Cal.1.f'ornia and Director, Department of Water Resources
ALFRED R. GOLZE', Chief Engineer
JOHN R. TEERINK, Assistant -chief Engineer
Southern District
1ert A. Howlett
C. Fowler ••
. . . . . . . .. . .. . . .. . . . . . . . . . . . . . . . . . . . • • District Engineer Chief', PJ anning Branch
This re:port was prepared under the direction of
~d B. Willets • • • • • • • • • • • • • • • Bead, Water Quality Section by
nell L. Gould ••••••••••••• Senior Engineer, Water Resources ld G. Hansen ••••••••.••••• Senior Engineer, Water Re~ooroes 1 F. Lo Bue •••••••••••••••• Junior Engineering Geologist V
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INTRODUCTION
As part of the Department of Water Resources I statewide program water quality monitoring, high concentrations of nitrates were noted in ground water supply utilized in the Grover City area of San Luis 1po County. These concentrations exceed the United States Public 'Vice Dri.Dking Water Standards for nitrates, and were of sufficient dtude to cause concern for the heal.th of the water users. This concern mpted the Central Coastal Regional Water Pollution Control Board to :f\md .nvestigation aimed at a more specific understanding of this critical. :r quality condition. This report presents the results of this study . recommendations for water well construction and sealiIJg practices that tl.d reduce the nitl:a.te concentrations in U1e g.rouncl wt1ters produced in area.
Authorization ~
Section 229 of Division 1 of the California water Code provides eral authorization for the Department of Water Resources to investigate quality of the waters of the state as related to all. sources of .ution, either independently or in cooperation with any person or any .er agency. The regional water pollution control boards under Section i2 of Division 7 of the California Water Code are authorized to request 'F!Stigation of any technical factors involved in water pollution. Starting k958, the Central Coastal Regional Water Pollution Control Board provided .s for this investigation under Project Nos. 58-3-3, 59-3-6, and 3-054.
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FUrpose and Scope
The primary purpose of this investigation was to determine the specific level of concentration of nitrates in the ground waters of the Grover City area, the extent of' the nitrate impairment, and to locate the probable source or sources of nitrates. In addition, reccmnendations were to be f'ormuJ.ated that would al.leviate or remedy the problem of nitrate contamination of the ground water supplies.
To accomplish these purposes, a program of surface water, ground water, and sewage effiuent sampling and analyses was undertaken, together with a limited study of the surface and subsurface geology. The data collected were evaJ.uated to locate the probable sources of nitrates in the ground water and factors a:ffecting ground water impairment.
The sampling program included the collection of samples of the surface waters from the ma.in streams tributary to the study area. In addition to the, department's regularly scheduled ground water monitoring program in the area, water samples frcm selected wells were collected for analysis tvice each year for a period of three years. In all, 30 wells were sampled and 91 mineral analyses of ground water were performed. Two samples were collected of the Arroyo Grande sewage treatment plant e:f'fiuent and analyzed for mineral content. Mineral analyses of the samples of surface water, ground water, and sewage effluent are contained in Appendixes A, B, and c, respectively.
Geologic sections were prepared at selected locations across the study area to illustrate the subsurface physical characteristics of the ground water basin, especially the extent and thickness of sediments -2-
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FUrR9se and Scope
The primary purpose of this investigation was to determine the specific level of concentration of nitrates in the ground waters of the Grover City area, the extent of the nitrate impairment, and to locate the probable source or sources of nitrates. In ad.di tion, recommendations were to be formulated that woul.d alleviate or remedy the problem of nitrate contamination of the ground water supplies.
To accomplish these purposes, a program of surface water, ground water, and sewage effluent sampling and analyses was undertaken, together with a limited study of' the surface and subsurface geology. The data collected were evaluated to locate the probable sources of nitrates in the ground water and factors af'fecting ground water impairment.
The sampling program included the collection o:f samples of the surface waters from the main streams tributary to the study area. In addition to the department's regularly schedul.ed ground water monitoring program .in the area, water samples fran selected wells were collected for analysis twice each year for a period of three years. In all., 30 wel.ls were sampled and 91 mineral analyses of ground water were performed. Two samples were collected of the Arroyo Grande sewage treatment plant effiuent and analyzed for mineral content. Mineral ane.J.yses of the samples of surface water, ground water, and sewage effluent are contained in Appendixes A, B, and C, respectivel.y.
Geologic sections were prepared at selected locations across the study area to illustrate the subsurface physical characteristics of" the ground water basin, especially the extent and thickness of sediments -2-
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I · comprising the aquifers. Lines of equal elevation of the ground water table or pressure surface were plotted to define the ground water gradient.
Water well construction and sealing techniques as practiced at selected wells in the area were carei\tlly studied to determine if any relationship existed between the methods and materials used 1n well construction and the nitrate concentration in the extracted ground water.
Area of Investigation
Grover City is located in the south coastal portion of San Luis 'Obispo County, about 10 miles south of the City of San Luis Obispo, as. ·shown on Plate 1, "Area of Investigation". The area of' investigation is commonly referred to as the lower Arroyo Grande Valley; besides Grover City, it a.iso includes the communities of Arroyo Grande and Oceano. Its boundaries are r01J8hlY U. s. Bighway 101 on the north, Arroyo Grande Creek I_ on the east a.nd south, and the Pacific Ocean on the west. Within this ' area of about 5,000 acres, about 1,500 acres are devoted to agricul.ture, about 2,500 acres support urban development, and the remainder of the area is essentially undeveloped:.
The lower Arroyo Grande Valley experiences prolOIJged swmner seasons which are generally warm and dry. These are followed by short, mild winters 1n which temperatures rarely drop below freezing. Rainfall averages about 18 inches per year and nearly 95 :percent of this amount falls during the months of October through April. Dense coastal fogs, however, a.re common throughout the year.
The water sup:ply for the agricultural and urban developments in the lower Arroyo Grande Valley is obtained primarily :from underground -3-
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reserves. The ground water supply is replenished by deep percolation of rainfa.11, applied water, and stream flow in the Arroyo Grande and Los Berroa Creeks. The A:rroyo Grande and Los Berroa Creeks make up the two ma.in stream systems which pass through the study area. The Arroyo Grande Creek drains a large area to the north of the study area, while the Los Berroa Creek drains a smaller area to the east. The two streams join about. two and one-hall miles east of their point of discharge into the Pacific Ocean.
GROUND WATER GEOLCGY AND MOVEMENT
The ground water basin which underlies ill of the ]JJwer P,r"!:'oyo Grande Vall.ey and extends uninterrupted southward toward the Santa Maria.
River is known as the Arroyo Grande Basin. From a study of the limited well logs a-va.ilable, it appears that the water-bearing sediments fill the ground water basin to depths of over 200 feet below the ground surface.
Wells in the lower Arroyo Grande Valley extract ground water from the entire depth of sediments. These sediments were deposited in the Recent and Pleistocene periods and contain lithologic units identified as alluvium, 1 • _sand dunes, aud the Paso Robles formation. These elemen~a are Rhrnre on Plates 2A and 2B, "Geologic Sections".
The all.uvium consists of unconsolidated clays, silts, sands, and gravels. The alluvial deposits vary in thickness from a few feet to about 200 feet and are found in channels which were eroded in the older Paso Robles formation. Water-bearing saJ:J.ds and gravels in the alluvium are generally highly lenticular or discontinuous and no delineation of aquifer thickness or areal extent coul.d be made. Most well.a in the alluvium studied in the course of this investigation were found to be perforated in the more permeable strata which varied in thickness from a few feet to about 46 feet. -4-
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Recent sand dunes which overlie older sand dunes occur only along a. DB.rl'OW strip of the coast. None of the wells studied penetrated the recent sand dunes.
A major portion of the area of investigation is underlain by the upper Pleistocene sand dunes. Because it is a thin veneer overlying the more productive Pa.so Robles formation, only a few veils tap this upper zone as a source of ground water supply.
The Pleistocene Paso Robles formation which underlies al.l the younger sediments and extends throughout the basin, ranges in thickness fran a few feet to veil over 200 f'eet. This formation, which consists primarily of gravel., sands, silts, and clays., is also highly lenticular, making aquifer correlation difficult. The majority of the ground water extracted in the lower Arroyo Grande Valley is derived from this formation.
There a.re no known geologic structures, such as faul.ts., which affect the movement of' ground water in the lower Arroyo Grande Vall.ey.
Since the sediments comprising the ground water ~~in a.re discontinuous and lenticular, it was not possible to delineate aquifers and it appears that the entire area is one of generally unconfined ground water. Therefore, ground water moves under the influence of gravity 1n the direction of the maximum downward slope of the ground water table.
The ground water table generally follows the slope of the valley floor, that 1s, it slopes in a southwesterly direction. However, because of a large cone of depression in the ground water table created by intensive ground water extractions north of Oceana, the direction of now 1n this immediate area is toward the deepest part of the depression. The shape of the ground water table is illustrated by the ground water contours for the -5-
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spring of 1960 on Plate 3, "Lines of Equal EJ.eva.tion of Ground Water, Spring 196011 • The lowest point in this cone of depression in the spring of 1960 was about 30 feet below sea level. Records indicate that this depression existed as early as 1945.
WATER QUALITY
The quality of the surface waters tri buta.ry to the lower Arroyo I Grande Valley is generally acceptable for domestic purposes and irrigation uses under accepted criteria. The total dissolved solids content of the I
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surface water varies between 500 and 850 parts per million (ppn) and the waters are generally of a calcium-magnesium bicarbonate character. Mineral ~ses of samples of surface water are contained in AppendiX A, "Mineral Analyses of SUrf'ace Water in the Vicinity of Grover City".
The total dissolved solids content of the ground water in the lower Arroyo Grande Valley varies trom 300 to 1,950 ppn, averaging about 600 ppn. These waters are generall.y of a calcium-magnesium bicarbona.tesulf'ate character. Mineral analyses of ground water samples frcm selected wells in the basin are presented in AppendiX B, "Mineral Analyses of Ground Water in the Vicinity of Grover City". The ground water would be considered generally acceptable for domestic purposes if 1 t were not for the high n1 trate concentration found in many of the wells.
The levels of nitrate concentrations in the surf'ace and ground waters were found to vary videly from each other. For example, analyses of surface water samples collected during the period from the fall ot 1950 to the spring of 1961. indicated either a low level or a complete absence of nitrate. In no case did the nitrate concentration of any surface water -6-
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.sample analyzed exceed 9 ppm. en the other hand, nitrate concentrations in / growid. water samples collected during the same period bad a median value of 67 ppm a.n.d ranged as high as 175 ppm at well 30R2. A graphic illustration of the specific nitrate concentrations in the ground waters, and the well. locations, are show on Plate 4, "Nitrate Concentrations in Ground Water, Sprine; 196111 •
POSSIBLE SOORCES OF NITRATES IN GROUND WATER
The excessive nitrate concentrations in the ground water of the lower Arroyo Grande Valley could originate in the water supply to the basin or f'rom within the basin 1 tself. As previously noted, the sur:face water supply to the area is relatively f'ree of nitrate, indicating that this is not the source of the nitrate impairment. F.a.1nfal1 on the area is relatively free of any mineral content aDd. therefore is not considered a contributor of n1 trate. F1naJ..ly, analyses or samples of ground water in the formations adjacent to the lower Arroyo Grande Val.J.ey area that constitute a source of' subsurface inflow indicate a complete absence of nitrogen or nitrate in this source., thereby e1im1nat1ng it as a potential avenue of nitrate intrusion. 'Ibere:fore, the source of nitrate impairment must be within the lower Arroyo Grande Val1ey.
In the loi,rer Arroyo Grande Valley the possible sources of nitrates in the ground water are the presence of nitrate-bearing sedimentary rocks in the ground water basin; the aevage effluent reacbi.Dg the ground waters from cesspools, septic tanks, leach lines, or the local sewage treatment plant; or the widespread and intensive use of nitrogenous fertilizers on farm land. In eval.uating these possible sources, it was noted tba.t the -7-
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concentration ot nitrates in the ground waters varied with time. These nuctuations in nitrate concentration in grQUnd water samples fran selected wells are shown on Plates 5A and 5B, "Nitrate Concentration Versus Time".
These nuctuations were observed to correspond with the fluctuations in the elevation of the ground water table caused by rainfall. It appears that there is & correlation between the period ot rainfall and the rise in ground water levels and the increase 1n nitrate concentration, both occurring after ( a time lag of about one year. This would. indicate that the nitrate impairment of the ground water was a result of ;the leaching of nitrates from the surface of the area followed by deep percolation and addition to the ground water body. The magnitude of the possible contribution :f'rcm the three potential sources noted above is discussed 1n the following sections.
Sedimentary Rocks
y In a report by the United States Geological Survey it was noted that in certain areas of California nitrate deposits in the form o-t sodium nitrate have been found. Generally, these nitrate · deposits are associated with shale or clay :formations l.aid down in lakes in the geologic past and occur as a result of physical. conditions ref1ecting climate and soil character rather than f'ran a unique geologic formation or condition.
Upon review of the geology, climate, and the character o! soil in the area, the possibility of a source of nitrate in the sediments of the Arroyo Grande Basin, appeared unlikely for several reasons. First, no evidence of B:rJ.Y n1 trate bee.ring formations in the source rocks of the Arroyo y Nobl.e, T. F., and Mansfield, G. R. "Nitrate Deposits in the Ame.rgosa Region, Southeastern California", United States Geological. SUrvey, Bull.etin 724-, 1922.
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Grande Basin sediments couJ.d be found. Second, as mentioned previously, there was a de.finite absence ot nitrates in the subsurt'ace inflow. In view of these facts, 1n addition to the apparent cyclic nature of the nitrate concentrations 1n the ground water, this possible source can be ruled out.
Danestic Sewage
The City of Arroyo Grande sewage treatment plant is located in the Fairoaks area and serves about two-thirds of the city's population which resides east of Halcyon Road. The pl.ant bas a design capacity ot 250,000 gallons per d~, and 1s presently treating about 220,000 gallons per day.
Effluent tram the treatment plant 1s discharged to spreading ponds south of the plant. The location of the sewage treatment plant and spreading ponds is shown on Plate 4. Sewage from the uneewered commercial and residential areas west of Halcyon Road including Grover City and the unincorporated Oceano area, is discharged into individual septic tanks and cesspools which serve the area.
The total pop.tlation 1n the sewered and unsewered areas contriboouting sewage wastes to Arroya Grande Basin is estimated to be approximately 12,500. Pop.tla.tion of the City .of Arroyo Grande is approximately 3,300; however, sewage from only about 2,200 passes through the treatment plant.
The present sewage production of 220,000 gallons per day is equivalent to 100 gallons per capita per day. Assuming that the per ca.pi ta sewage output is the same in the unsewered area, the present popll.a.tion of 12,500 is producing about 1,250,000 gallons ot sewage per day, most of which eventual.l.y percolates to the underlying ground water body.
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The mineral analyses of two samples of sewage efnuent from the Arroyo Grande sewage treatment plant indicate that"nitrogen was present in concentrations of 11 ppn and 31 ppn, indicating nitrate potentials of 48 to 136 ppn, respectively. Assuming that the maximum concentration of 31 ppn of nitrogen was present 1n al1 of the sewage output in this area, it is possible that as much as 117,000 pounds of nitrogen per year could be &dded to the local. ground waters i"rom sewage wastes. .Although the nitrogen in the sewage effiuent is not in the nitrate or nitrite form, it is probable that oxidation and conversion to the nitrate form do occur.
Fertilizers
A land use survey conducted by the department in 1959 indicated a large part of the lower Arroyo Grande Valley was devoted to irrigated !381"iculture. Results of this survey are shown on Plate 4. Much of these lands are still under irrigation at the present time. The two major crops in the area are celery and strawberries. About 450 acres east and south of Arroyo Grande Creek are used for growiJ:lg celery, and sane 300 acres west and north I of Arroyo Grande Creek are used for growing strawberries. In addition about I
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2, 000 acres within and ad.Joining the area of investigation are planted to corn, beans, broccoli, and other miscellaneous crops.
Commercial. :fertilizers containillg a high percentage of nitrogen are applied to the crops grown in the area. The average anrn,al application of nitrogen for celery is 290 pounds per acre, for strawberries 145 pounds per acre, and for other crops, about 90 pounds per acre.
Based on these application rates, it is estimated that the quantity of nitrogen for ·a11 crops combined tote.ls some 350,000 pounds. The actual -10-
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I . i appl.ication of fertilizer for a single year on the overlying basin may well. be two or more times this amount because of the occasional practice of double cropping.
Not e.ll of the nitrogen applied to the agricultural lands :remains in the basin to add to the n1 trate impairment. Much of it is absorbed in the growth process of the p1ants in widely varying amounts depending on the particular crop. It is estimated that ot the 350,000 pounds ot nitrogen applied annually, about 2001 000 pounds remain in the basin as a result of excess applied waters and Ullharvested root and pl.ant systems.
It therefore appears that the major source of the nitrate :illlpairment to the ground water of the lower Arroyo Grande Valley is the nitrogenous f"ertilizers applied in the intensive farming conducted in this area. These nitrates are transported to the ground water body primarily by the deep percolation of rainfall and secondarily by the deep percolation of irrigation water appl.ied in excess of the consumptive use.
WAT.ER WELL CONS'mUCTION PRACTICES THAT
MAY ALLEVIATE lf.I'l'RATE IMPAIRMENT
Whil.e there appears to be no feasible means to economically eliminate or greatly reduce the preoom:1nant sources of nitrates to the ground waters of the lower Arroyo Grande Valley, there are certain vater well construction and seal.ing practices tbat can be adopted to :illlprove the qua.llty of the ground water extracted from this basin.
As part of this investigation, drilling techniques and construction practices f'or a total of 21 wells in the basin were evaluated in terms of their 1n:f'l.uence on ground water impairment. Data on the method of drilling, depth of well, extent of' perforations., existence of gravel packing and seals, -ll-
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and nitrate concentrations in the ground water from the selected wells were '
collected, and are presented in Table l, 1
11 3Ummary of Well Construction
Practices". These data indicate that there is a relationship between the degree of nitrate concentration and the method of developnent of the wells.
More than one-half of the wells presented in Table l had nitrate concentrations in excess of 45 ppn, the recommended upper limit in the United States Public Health Service Dr1nk1ng Water Standards. Each of' these wells exbi.bited one or, more of the following charaeteristic:s: It had been drilled to a -depth l.ess than ·70 feet; it bas been perforated· at levels less than 70 f'eet below ground surface, or it had been gravel packed f'or most of its depth. These factors probably account for the high nitrate concentrations in the ground water extracted from these wells. Wells perforated at the shallower depths and those with gravel packing provide avenues for shall.ow ground water conta1n1ng high concentrations of nitrate to enter the wells. The quality of t~e ground water fran the deeper strata is apparently low in nitrates and Sllltable for danest1c purpo~es.
It therefore appears that water wells drilled to the deeper strata and perforated at depths of more than 70 feet below the ground surface woul.d provide ground water free of excessive nitrate concentrations. If a gravel pack is used the top of the pack ahould be 70 feet or l:lDre be1ow the ·ground suri'ace, and the space above .tbe .. pack should be .adquately sealed to the ground surface.
These water well construction procedures should all.eviate the present problems; however, the deep percolation of return flows and precipitation will continue to carry waters of excessive nitrogen concentration :trom the fertilizers applied on the surface to the ground water bcdy. OVer a period of time, this condition could continue until most of the ground -12-
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TABLE No. l
SUMMARY OF WELL CONSTRUCTION PRACTICF.s
State well :-- - . Perforated~ - . Gravel . --- -- :Range o? . . . number : ~:eth* . intervals* . l!Cked*: Seal :N?3 in ppn • . 32S/13B-19Nl 37~C) 32-37 No Cone. Base 15-133
-28El. 133 R) 93-133 36?-133 . 11-36 14-22
-28E5 22 - .. - 45
-29Dl ll5(C) 79-85, 96-100, No - 0-2
105-ll.3
-29~ l.30(C) 60-70, 113-117 No - 115
-29D3 70 61-70 - - 95
-29El 180{R)? 36-18o Yes Yes 36+ 3-144
-29E2 l80?(R) 36-180 Yes Yes 8-41
-29E3 18o~R} 36-180 Yes Yes 37
-~l 223 R) - Yes - 9-60
-2902 250~R) 130-250 Yes 20 2-4
-2903 250 R) 103-250 0-223 37 2
-29Pl 87 - - - 3
-30Hl 51. 44-50 No - 104-163
-30H2 61 55-61 - - 46-124
-30K6 160 15-21, 29-Bo,
91-103, 108-ll.3 - - 10-78
-30L2 57(C) 54-57 No - 5-67
-30Pl Bo - - - 15-20
-30Rl 63 58-63 No - 62-115
-30R2 l28(R) 81-l.20 0-120 - · 175 .. 3lBl 44(c) 38-44 No - 9D-107 -32Al 1'6~c) 4o-1'6 No - U-J.67
-32D2 li.6 R) - Yes - 24
-32D4 107.5 - - - 35
-32Hl 38 - - - 67-125
-32L2 95 60-66, 75-89 - - 3
-33n 82 - - - 6
* In feet
C - Cable Tool
R - Rotary
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water is not suitable for domestic purposes. The long range solution is to obtain a water supply of adequate qµality :f'rom an alternative source for use ·1n the domestic suppl.y systems of the a.rea., leaving the ground water for irrigation uses.
SUMMARY OF FINDINGS
The high level ot concentration in the ground waters in the vicinity of Grover City appears to be primarily the result of widespread application of commercial fertilizers on the overlying agriculture lands. .. Additional amounts are the result of deep percolation of sewage ef:f'luent :f'rom the Arrcyo Grande sewage treatment plant and the septic tanks and cesspools serving the unsewered portions of the valley. Natural precipi tation and applied irrigation waters, which percolate downward through the soil., transport the soluble salts of the fertilizers and sewage to the underlying water-bearing zones.
High nitrate concentrations were found to exist primarily in wells with depths of less than about 70 f'eet. In the deeper wells, nitrates appeared. to be excessive only if' the wells were perforated in the shal.low depths or were gravel packed.
:RECCM-1ENDATIONS
Rigid standards for the initial construction of water wells and the possible destruction or disuse of wells shou1d be developed to protect the deeper ground water supplies f'rom further impairment :f'rom the application of nitrogenous fertilizers and domestic sewage. Pending the adoption of such water -well standards., the nitrate problem in the Grover City a.rea woul.d -14-
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be materially alleviated if' the following precautions were observed in the drilling of wells:
1. Wells for domestic purposes should be drilled to depths greater than 70 feet in order to penetrate the deeper water-bearing zones.
2. To prevent shallow; poor quality water from entering wells, only the deeper water-bearing zones should be perforated.
3. Gravel packing should not be placed between the ground surface and a depth of 70 feet for all wells~ This will greatly reduce the possibility of' nitrogenous water percolating and mixing with the waters in the deeper water-bearing zones.
4. Pollution seals for rotary drilled wells shou1d be placed at a depth of at l.east 70 feet, and in the case of cable tool. drilled wells the seal shoul.d be p1a.ced at least 5 feet be1ow the base of the pit used to install the hydrau1ic jacks.
5. A sanitary seal shou1d be placed at the ground surface a.round wells to prevent surface and shal.1ow ground waters fran entering the well~ -15-
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INVESTIGATION OF NITRATES IN
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PERFORATED IHTERVAI..
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;J'101f'fEAENTIATEO TERTIARY FORMAT'IO*'(S
ptOTE : LOCATION OF SECTIONS '-RC SHOW'flt C~
STATE OF CALIFORNIA
DEPARTMENT OF WATER RESOUR
SOUTHERN OISTRICT
INVESTIGATION OF NITRATES
GROUND WATER, GROVER CITY
SAN LUIS OBISPO COUNTY
GEOLOGIC
-SECTIONS
A-A1 AND B-81
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SECTION c- c'
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LEGEND
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STATE OF CALIFORNIA
DEPARTMENT OF WATER RESOURCES
SOUTHERN DISTRICT
0 INVESTIGATION OF NITRATES IN
GROUND WATER, GROVER CITY,
SAN LUIS OBISPO COUNTY
GEOLOGIC -SECTIONS
c-c' AN o o-o'
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LEGEND
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LINE OF EQUAL GROUND WAT
-10- ELEVATION
A---A GEOLOGIC SECTIONS
.TATI[ 01' CALll'OflNIA
01!:PARTMENT 0 .. WATE" ,.ESOU,.Cl!:S
SOUTHK"N 01aT ft IC T
INVESTIGATION OF NITRATES IN
GROUND WATER GROVER CITY
SAN LUIS OBl~PO COUNTY
LINES OF EQUAL ELEVATION
· OF GROUND WATER
SPRING 1960
.Z5
SCALE
5 1962
C")
0 C")
t1\
l>
z.
T. 32 S
T. 12 N
25 FAIROAKS
-· -
R 36 'N R 35W S.B.B. a M. 30 "°'*--.. Ml
21 ARROYO GRANDE
; ,, ... Berros
/ · .-
.33 ! F / · • . ,. ' ' '
. ' .·,· • • . Kl
'!;I . ... ,
. -~~/ -~" ... ' -,J,'!•i/ . .. . _..,,,.,.,, r • ' • f • • ,f"'.,./ +' .,. ,: I : .. ... ,' .- ;'
'I•:, ",/.': ;,.': r, ,# ..
· . . - L 2 _ •
.,/· •· ... . '
29 22
·-
LEGEND
• SURFACE WATER SAMPLING STATION
C=:J IRRIGATED AREAS IN 1959
NI. WATER WELL
- SEWAGE TREATMENT PLANT
APPROXIMATE AREA IRRIGATED
WITH SEWAGE EFFLUENT
7 0 . NITRATE CONCENTRATION
11 DIAMETER
~ IS PROPORTIONAL TO
' IOOPPN NO] 7
STAT!!: Of" CALIIFO,.NIA
DEPARTMENT 01" WATER RESOURCES
SOUTM~IIIN 019TfltlCT
INVESTIGATION OF NITRATES IN
GROUND WATER, GROVER CITY,
SAN LUIS OBISPO COUNTY
. ~
NI TR ATE CONCENTRATIONS IN GROUND WATER
SPRING 1961
SCALE .25 I MILE
1962
.. V • , • 1 - • ; .:.,._·t,..~-\!' _:_:
,-
~
a.
a.
PLATE 5A
175 r------..---------.------T--------r------ - --,----1----~-------.------ ·- ----~------ 32S/13E- 30Hl ...
125 t------t-------f-------f------+--------+---+----1------+-----+-I _____ .__ ____ _ 0 ..__ _____ ,___ _____ .,___ _ ____ .,___ _ ____ .,__ _____ _,__ _____ .,___ _____ ..,,__ __ _;_ __ ,.L_ _____ ..1-_____ _,J 1953 1954 1955 1956 1957 1958 1959
Y~AR
1960 1961 1962
9TATlt 0, CA~Lf'o,tMA
OEP.ARThotl!:""1" Of'" W~T£.I'\ ..CSOUlltOCS
INVESTIGATION OF NITRATES. IN
GROUND WATER, GROVER CITY,
SAN LUIS OBISPO COUNTY
~
NITRATE CONCENTRATION VS TIME
- ------ -
'
l
,!
I
I
I
I
~
a..
Q.
z
I :~~: , .
PLATE 58
175 ,-------,,,...._----,------.------r------,------,--. ..,..._ ---..---------.--------:,-----,-------, J
,,
150 1------+-------+-------+-------+------+------ht--,~1 ---------------,1------+-------1 ,' \ j \
125 t-----+-----+-------+------+------+-------A·~ '---1\1-------if------+---· --4-----~ ~'*'-· : ,, '
! ,,,, \ ',~~'\
1 / 32S/13E-30H2
100 1--------+-------l------+------+-------i-~:.__.il __ ---l _____ -11_-\~·....J-.. ~--~-----'--------1 I ,' I \ ,, / , 32S/13E-32Hr/ / ·' \ /\ \/ /
75 1-------+------+------+------+---..;/,C-----l----4----+----t----1--#-----+--l-#/ _____ I--____ --I ., I ' / \ \·
- -., - - -- - . 32S/8E-32A/ \1 \) 50 1-------+------+------+---=.....---=--t-------+-~,,_----l,-----___..._-+-___ _!l~l--------+----------I . .__ ---.. " I
25 l-----~. -+------+-------+------t------+------+-------l------4------~------l " QL-____ __._ _____ ..,L_ ____ __._ _____ ....1,_ ____ --1, _____ _._ ____ ___J _____ _L _____ L.,_ ____ __J 1953 1954 1955 1956 1957 1958 1959
YEAR
1960 1961 1962
STATIE 01" CAL.ll"OANIA
DEF"AAT MENT 0, WATER f11Ed0UAC£S
SOUTHIERN DISTRICT
INVESTIGATION OF NITRATES IN
GROUND WATER, GROVER CITY,
SAN LUIS •)BISPO COUNTY
~
NITRATE CONCENTRATION VS TIME
APPENDIX A
MINERAL ANALYSES OF SURFACE WA'lffiS
IN THE VICIHI'J'Y OF GROYm CITY
t Eati- ,Temper-• I I parthler million Parts e!!r milUon t 1 mated I atW'e 1 I ECxl06 I Constituents 1n I ' I 1Total I Tote.I 1PerLocation I Date I flow I ,men I pH I at I equi-anta per m.illion I I I 1 dis- 1 hard- scent 1 sampled 1 in 1aampled1 , 25° C I t I I I I I I I I F : B 1Si021solved1 neaa I Na ots I OF I I I Ca I MB I Na I K I co_a • HC03 ' S04 I Cl I N03 I : 1 1solida:(CaC03)1 Canyon Noa. 1 and 3- 3-61 0.25 64 7,5 1,555 61 58 175 28 0 510 66 255 0 1.2 0,50 42 968 393 47 2 at Highway 101 3-"M 4.78 7.00 o.n lf 8.31 !';'ff 7.2i' lf Arroyo Grande Creek 3-27-61 - 62 7.9 11,000 222 274 2050 55 0 393 744 3464 0 o.4 1.3 18 7,626 1,676 72 at s. P. Crossing ~ ~as.I!~ Ir ~~ ~~
Arroyo Grande Creek 2 .. 13 .. 54 12.7 - 8.l 935 110 50 43 4 - 375 180 39 6 0.5 o.oe - 684 480 16 at Arroyo Grande 00 4.lo ~ o.11" rn 3.76 r.w o.m
Avenue
2- 6-58 35 52 a.5 726 82 36 26 2 8 296 128 21 3 0.1 0.12 25 491 353 14 4-'lo 2,.95 ~ ~ o.3' 4.85 2,66 0.00 o.os' p
,
1 ..... Upper Los Berroa 3- 3 .. 51 o.s 66 8,3 2,160 251 118 98 6 2 547 689 123 9 0.2 0.23 26 1,792 1,113 16 Creek at Valley Road !2.56 9.70" 4.25 o.I6 ~ s.'96 14.89 3-44 o.'14 Arroyo Grande Creek 11-10-50 0.5 - 8,3 1,010 122 59 45 5 12 418 220 36 0 - 0.02 30 735 547 15 o.5 mile S/o 6-"0V 4.85 f:§6 03 ~ rn ... sa r.o1' lf
Highlfa.y 101
Arroyo Grande Creak 2- 4--fJO 8 56 7.9 1,165 135 59 54 3 0 424 263 53 5 0,7 0,06 31 825 580 17 at Hi.pay 101 Os 4,85 2.36 o.[a Ir ~ 5.48 1.50 o.oa
Arroyo Grande Creek 2- 6-58 35 53 a.2 550 86 36 24 2 0 323 129 21 2 0.3 0.09 25 491 365 13 Gaging Station 4.30 s.oo" 1,05 0.04 0 5.30 2':68 0.60 0,04 Tar Springs Creek a- 2-61 2.0 68 8.2 1,060 126 57 40 2 0 439 220 42 0 0.3 0,10 22 678 551 14 0,1 mile E/o Arroyo 6,30 4':7Y L75 D.05 0 f:2o 4.59 r;rr 0 Grande Creek
,, .-........ , • 41 , • - - ~-,~--':"' - .,.,~,- , - • :.-;,: ·•nJ>.•,;,~·· - oe , •• ·-;;,;-:-:.'l:.,r~:("3~~~~'ll"R":'~~~,::--,,i,'"',~:•·:'-',_,,....~,...._'Y"'"",..-~.~-,=.~~----.#'·· w~- ,, .. -, ·,--•,- ... -,...-.;---i,,,- ' •. - < -·.;
~=-, -
- -"----··- --... - - - - - , --.-
APPENDIX B
HltERAL ANALYSES 01 GROUND WATERS
IN THE VICINITY OF GROV!':R CITY
:Temper-1 I I parts fir mllllon Parta 2!!r million 1
: , ature : I ECz106 I : I I :fatal: Total :PerState well I Date 1 when : pH : at I Conetituenta in eqUiva-enii pe.r iiilffion I : ; : dis- t hard- :oeut number : 1a111pled :sampled: I 25° C I : r : : I t I t I p I B , s10:2 ,1olved1 neas I Na.
I Op : : : Ca : ~ : Na. :
K : C03 : ijJ03 1 ~04 : Cl . N03_: __ : __ : ,~olids: (ce.003):
'.}2S/1JE-l9Nl 9-29-54 1'J 6.') 4~ & b & l 0 22 41 &a ~ 0.1 0.03 - 292 ')2 52
0.03 0 ~ 0.85
8-29-57 - 6.5 5~ 22
~~1 64 2 0 22 2L ~ 86 o.o 0.20 2, 336 117 ~
1.12 I:79 0.05 0 'o:3' 1.21 r.lio
2- 6-58 - 6.3 511 18 & ~ 1 0 22 33 ~ ~ 0.2 0 30 353 100 53 o.;o o.U3 0 ~ ~
2-16-59 - 6.4 475 &a 16 h 1 0 18 P.n ~ ~!44 o.o 0.0.3 33 353 133 46 ~ o.Ui' li o.JJ 9-22 .. 59 78 7.2 620 26 & ~ l 0 24 i~21 ZL 114 0 o.,o 27 %1 1.33 51 -a; o,oj 0 °'" 2.10 t:1'i~
')-20-60 - 6.4 716 ~~5')
16 ~ 2 0 ~?li2 ~ 2L 75 0 0.10 11 456 155 52
1.50 0.05 0 2.21 r.Il
3- 2-61 - 6.3 725 ~ & 2!_ 2 0 26 80 ~ ill.. 0 0.10 26 490 164 49 lo')O 3.15 'o.1iTf 0 o.lj.3 rn 2.j5 2.15
-22Cl .3- ,-01 - 6.8 390 20 14 48 2 0 108 41 .2L 0 o.8 o.26 50 288 108 49
1.01 Ll5 'wo 0.65 0 r.,g 'o:'$ 1.55 0
-22Pl 3- ,-61 - 7.5 2,200 w., ~ 98 4 0 621 822 121 0 0.2 0.21 21 1,9.36 1,268 14 6 o.~ ~ o.fi 0 Io.Ia Yr.12 Y-1io 0
-28El 9-29-54 13 7.4 1,020
~ ~ 46 2 0 422 ¥.ts ~ 14 0.1 o.o .. 692 499 17
5. 1:'5I ~ 0 6.91 1 • .3 0.22
.3- ,-61 - 7.5 1,070 112
~ & 2 0 411
~ 60 22 0.1 0.10 24 660 497 lj
5.5j 0.05 0 b.13 ~ 0.35
~,_-,. ·::••· • ,1.- ·:c.__e. •-' , .r.,., ,. • • r. "C,··~·. ~ ' APIUDIX B
t,aNERAI, ANAL'YSES OP OROOND WATERS
IN THE VICINITY OF GROVER CITY
(oontimled)
cTemper-1 : r
COMtituerrta in f8M8 f&J' million
Parts E!r million
r a:ture : I ECxlo6 : r . : :Total. i Tatar :Per- equS.valents per million . State well s Date & when : pH : at : . . : : : dis- : bai'd- :oent number 1 sampled reampled: I 25° C r : : I . . . 1 ~NO 1 F : B : s102 :solved: ness : Na.
OF : : : C& : ~ I Na I IC ; C03; HC03; so4 ; Cl I 3 I : : :eol1de:(caeo3):
.'32S/l.3E-28E5 J-~l - 6.8 6.30 40 28 trs 1 0 l:~1 ~ !Jo ~ 0.1 0 18 422 215 .34 2.01 2.28 0.0, 0 • 5 1.12
-2,01 9-2~~ - 7,8 934 ~ ~ lj4 bs 0 412 144
~ 2 0.1 0.05 - 583 442 18 3.99 ~ 0 r.75 2,99 o.o4
J- 5-57 66 7.4 ?87 67 42 44 4 0
~ 112 & 0 0 o.o6 16 481 .341 22
J:,i 'Pi7 1.91 0.09 0 2.3.3 a
I1
3- 3-61 7.3 980 108 44
~ ~ lli.. ~ I - 642 449 to, 0 0 0 0.1.3 29 17 0 5.39 .3.85 0 3.10 0 -29D2 5- 9-61 70 7.4 620 ~!45 ~ 48 2 0 &i &a ~ ~ 0.1 0.25 29 466 201 34
2.10 o.154 0 5
•29D3 3- .3-61 - 7.2 480 '!L. 11 146 2 0 ~ ~ 46 .22.,_ 0 o.o6 29 320 112 47 1,35 0.89 2.00 0.05 0 ~ 1.53
-2';)El 3- 6-55 - 7.4 - ~ 42 44 - - & 116
~ 12 0,2'1 - - 705 ~ 19 ~ 1.91 r.tii' o.19 --
2- 6-57 - 7 • .3 - 80 ~ 42 - - ~ 112 42 35 0.20 - - 595 338 21 tr.oI r.,; 2 • .33 m o.57'
11-11-60 - 7,9 ?63 67 .31 ~ ¼.o, - 141 160 ~ ~ 0,2 o.08 35 585 29~ 28 'f."j1 T.91 T.1Ri T-15
3- ~l - 7.2 665 n ~ ¥.;a ¼.a,; 0 122 & 62 144 0.2 O.J.,3 27 610 314 27 tr r.oo ~ cy
-29E2 2- 6-57 - 7.8 - 76 35 41 - - 271 105 44 34 0.10 - - 580 ,,3:,4 21 'r.1§ T.W ,1-.78 ~ :-T.'iS ,, .I:111 o.s!
~---=.........,.,.i _ ____,--:.;_
.-~ - - · - ... ---- --L..........::..-_____________________________________ . a.4~
APPENDIX B
MINmAL ANALYSES OF GROUND VATEIIS
IN THE VICINITY OF GROVER CITY
(oont1nued) ... - •=a,
:Ttrnpe:r-: • 1 Parta·-per million : ature : : ECltl.o6 , Constituents 1n parts per million : s : :Total : Tota:r:PerState well Date : when : pH : at : equivalents per lllllion : : ; : dis- : hard- :oent number : 11ampled :sampl'ld: : 250 C : • : : : : 1 1 1 : F : B : S1<>2 :solved: ness : Na OF : : : Ca l Mg I Na : K : co,: HC03 I s04: Cl I N03 I : : :eol1ds:(CaCOl):
J!S/13£-29E2 11-11-60 - 6.8 786 §1__ .n__ IJ8 2 -- !Q2__ 122 53. _ 53 0.1 O.<H )5 658 )05 26 » r.,11 T.'07 ~ ~ 2.55 r.tij I:4V
,,.-
-29E3 11-11-60 - 7.0 8o6 71* 1S._ 48 1._ - ~ 136 §J_ 'fl 0,1 O.~ _34 598 328 25 Y-71 ~-2.08 ~ Y-J7 l:"m 1;78 rn -2901 11-13-50 - 7.5 872 90 43 37 J__ ~ 361 ,UL ~ 10 - 0.01 _34 558 4o2 17 1i':1ij M'f I:bi o;(f/ 0 ~ 2~ o.~o 'o;iX
tlJ
.:, r 6-,J 65 7.4 ~ ~ 45. _ 38 1.._ ~ .36.3. 1116 ,lL_ ..L_ 0.2 0.01 25 591 442 16
5.09 J:Ji.l1 T:b5 o.07 o OB ~ 0.99 ~
2-18-59 64 7•'J 842 80 22__ '6_ 2 o 211 ~ ..5.1._ 60 0.2 o.06 30 601 360 18 1J:l)o Y-20 T:'58 ~ 1S J:115 J;n r.sa o.'r/
9-22-59 68 a.o 824 - - - - ~ n5_ - L - - - - - 364
0 3-85 ~
8- )-60 - 7.2 939 .22__ li6 ,a 2 o _m_ !2l._ 41 4o o.2ij 0.11 24 651 435 16 1J;j2-;:,s"m;~ 0 ~,-;IBr:i7~
1~ 6...(;o 66 7.a 903 - - - - o m._ - ~ - - - - - 4.39
0 "&:08 1.2'
-29G2 2- 4-57 - 7•7 - 100 46 44 - - )81 142 46 8 Oo20 - - 765 4)8 18 ii.99 J:78 1, 91 b.21i T.°;b r.;ci a.ii
2-18-59 64 8.1 981l 110 -51_ 33 2 O 415 ~ ~ 4 0,2 o.o, 31 661 49.3 13 ~~t:llli~ 'ti b.lm~o.,Oo.cjg'
-290.3 2- 4-57 - 7.5 - ~-- 116 40 - - .376 ~ ~ 8 0.20 ., - -- 745 428 17 ~ ,.,s r.,i rn ~ r.<11 0.13 1 . !)!}'., '., -·~: .,,~(~:~r,;;~,..;iW 1\lllJtti'IW(,:t.'ll!li(-.Jb."ti!'.f~~ Wll~ uiit1i:/ilf,<l!l!:li!.!i~·~~-~,;'3lliii;ffil'a(;;JH,l.~,m.wfll~Wi!-i,N,,,s:.,~il",.,...,t'W.;1, ,-.,.., '"'''""'' •• , ... ,,.,,,., .. ,,,,,.,-.. ,~,,,-..,, .. ;,,,..., ....... _.. ·-~.-- '"' ' ,, ._ ,_. ·1 J'~f. f1 ,,
•._pPEJL - ~: . MINERAL JlliALYSES OF GROUND \-TATERS
IN THE VICWI'l'Y OF GROYm CI'l'Y
(continued)
:'l'emper-:
; ECx1o6 ; Constituents in parts per m1llion
Pe.rte per million
: a.ture : : : 1Total; Tota.l :PerState ,,:ell Da.te , when : pH . a.t I equivalents per million . : : : : dis-, he.rd- :oent number sampled :sampled: : 250 C : : : I . . :
s04: : I F I B 1 S102 :solved: ness : Na.
I OF f : Ca. Mg : Na : K ; C0.3 : HC03 1 Cl ; 003 : I : :sol1ds:(caco3):
J2S/l,'.3E-J0H2 9-22-59 - 7.3 652 ~ ~~64
40 2 0 ~ ~~14
64 ~ 0.18 o."6 26 two 219 28
(continued) I:'15 0.05 0 1.80 •
2-2~0 62 7., 700 - - - - 0
~ - & 110 - - -- - 238
0 rm
9-20-00 - 7.6 69.3
~~2?
20 40 2 0 ~ L i?41 86 0.2 0.12 .32 452 1~ 30
1.69 1.75 0.05 0 2.50 1.12 Ctr td
J
.3- 2-ol 1., 100 26 42 2
~ ~ ~~3 \1\ - 26 1162 2)4 28 .5.L -- ~ 0.1 0.10
2.53 T.i1i l.'85 0.05 •
-.30K6 11 ... 13-50 - 8.l 872 & 24 48 2 0 &s ~ 42 24 - 0.02 36 545 3.30 24
1.37 2.09 ~ 0 • 1.18 0.39
.3- 5--51 -- 7.5 - ZL tro 41 - 0 210 lll
~ 45 o.:i!O - - 535. 4.38 .~2
.3.59 r.n 0 J:liii '.h'.31 o.72
8- .3-60 - 7.6 998 & 41 ~ l 0 ~ 142 100 ~ 0.2 0,1, 25 663 .388 2.3 .3 • .39 0.0.3 0 .3.22 ~ 2-!i
-301.2 9-29-54 96 7.5 761
4~61
41 40 2 0
~ 124
~ 20 0.1 0.20 - 580 ,~ 18
~ r.,i ~ 0 r.;a 0
8-29-57 - 7.a 901
~ 40 41 2 0 .317 fil_ 51 't.w 0.10 0 • .30 20 631 3,1 20 y.;; 1.81 a.or; 0 5.20 2.39 1.41+
2- 6-58 62 7.2 855
~ 47 i~70 2 0 311
~ ~ 22 0, 0.10 31 590 .370 19
.3.90 ~ 0 5.10 0 • .35
9-29-58 - 7.4 a:n - - - - 0
~ ~ - 46
1.jo - - - - -- 3'11
..
'
.lPPZNDIX B
MINERAL ANALYSES OP GROUND WATERS
IN TH& VICINITY OP GROVER CITY
(continued)
- ---- -- rTemper-1 I I p!lrts per million Part-aper m1llion I : ature : s ECxl~ : : I r :Total I Tota!" :PvState vell : Dat0 I •1hln Jfi l at I Conatituent, in ~uJ.va.1.ents per million I . I : dis-: hard• :oent : . rwmber : au:pleci : i;~.z,1pled: : 250 C : : Mg . : 1 co 1 11:0 1 S<>4 : : )K)I , l B : s1~ :solved1 nesa : Na Ca . Na. K Cl °F I : I I : I I 3 : 3 : : ' : : : 1aoUds:(CaC0l):
J2S/13E-30L2 2-18-59 - 7.4 741
~~60
}j__ ~ 2 0 & ~ ~ ¥.as 0.1 0.03 38 529 325 23
(continued} 2.90 0.05 0 3.55 .15
9-22-59 65 7.0 865 ~ ~ 4o l 0
~ ~ & 28 o.u 0.18 28 645 389 18
1.73 0,02 0 ,39 o.45
2-2~0 65 7.3 950 & 1J4 48 2 0 & ~ 6'>
~ o., 0.12 ,o 590 406 20
;:n 2.09 ~ 0 0 T.1io
r1
.1 9-2o-60 7.3 ;.5 ~ ~ 42 2 0
~ ~ & :,--- - 22 0 0.15 13 686 41, 13 ~ 'o;o5 0 0.36 '
,- 2-61 - 7.1 1,5,0
~ f.J2 60 bu 0 281 l.60
~ 1.6 0 0.10 25 l,~ 644 17
T.l;o 0 no 3.35 1 o:1b
-.30Pl 11-12-50 - 7.8 7~ ~ 26 &r 1 0
~ ¥.fi 32 15 - 0.02 '37 512 )146 19
T.ili 0:0, 0 • 9 0.90 0.24
,_ >'l - 7.5 910 94 .. , 38 2 0
~ 110 ~ 20 0.1 o.oi,. 27 574 410 17 ~ J;sI ~ ~ 1> 2.31 ~ -311U 2- 6-58 61 7.1 7/2 4-8 32 52 2 0
~ 67 'lB P.r, 0 0 30 530 250 :n
l:tm r.g-u r.w; ~ lJ r.» 2.20
10- 6-58 65 7.4 ,i.a 65 30 f.-;; ' 0
~ 99 ~ ~ o., o.o 35 470 285 29
J;l1J T.IJ1 ~ li • r.o,
2-18-59 - 7., 680 65 29 lf4 ., 0 1l!6 96 57 62 0.2 0.15 " ~, 280 25 ~ ~ L90 o.(IJ 0 3,05 2.00 l.bO I:oo
,-.22-5j 66 7.4 847 63 30 61 3 0 124 106 ~ ¥.k 0 o.42 2~ 585 260 j2 ,.14 T.Ji'.7 m o.o8 0 2.03 2.08 •
'\
APFUDIX B
HINERAL ANi\LY5ES OP GROUND \i.A.TERS
IN Tl£ VICINITY OF GRO'Vm CITY
(oarrtinutd)
,temper-: I I
Ocnat1t111nt• 1n pe.rta Er m1llion
Par1a I?!!: m!llon , 1 ature 1 I ECxlcti I I I I ,total : f otlll : PerState well I Dat• I when I pi I at I equin.hnta ptr m1ii1on I I I 1 dl•- 1 hard- zoent numbor , 1ampled 1aampled1 : 250 C ; : t I I I I I I , : B 1 Sl~ 11olvtd1 n .. a a II& Of I I ,ca:~1* : I: : C03 : HC0.3 : S()q I Cl I N03 : I I 1aol1da: (CaC03):
.32S/1JE-JOR1 2-~o 65 7.3 8')2
~ tr, lj6 2 0 !?fo 122 82 ~ o., o.o, ,2 560 JIJ'J 22
(oontinued) 2.00 a.al 0 ~ 2.)1
9-20-60 - 7.7 1,005
~ 41 & 2 0
~ ~ P.u 1L. 0.1 o.o, 21 '/')2 1+21 16
3.IJ5 0.05 0 3 1.23
3- 2--61 - 7.4 900 82 41 & 2 0 ~~~5 ~ ~ ~ 0,2 0.38 28 606 m 18 ~ J:1iJJ o.'ci 0 .,o co
I -30R2 3- 2--61 7.1 760 57 25 63 2 0 59 l<ii 67 175 0 o.olt 2, -...;J - 554 245 36 2,8.3 T.o'i 2.15 0.05 0 ~ 2.21 1.89 T.'8i
-31B1 6- ,-5, - 7.2 l,U4 107 'J7 73 4 0 258 163 ')l ')O a.o 0.10 -- 795 422 27 537 Pilf 3.16 o.iij 0 ~ 3.85 2.57 1.ii5
3- ,-01 - 7.1 1,180 !22... & &.. bu a 250 210 99 107 0 0.15 'l'/ 672 4j3 23
5.35 2.,0 0 ~ tr;j; T.'i"§ r:,;
-32Al 6-11"'54 - 7.lj. 866 71 ~ 39 l 0 243 117 21._ 63 0.2 o.o - 1m 352 19 ~ ~ ~ 0 MIi T.Iio 1.50 1.02 6-2,-57 - 7.7 550 4o 22
~ l 0
~ &; &t ~~6')
0.14 0.65 23 372 168 26
r.;g r:m o.6! 0
2- 6-58 - 7.5 351 10 21 22 l 0 22- 21
~ ~ 0.66 0, 28 240 113 _,o o.55 r.,s ~ o.ol 'li 1.15 o.43 9-29-56 - 7.lj. 9f8 - - - - 0 100 - ~ - ~- - - - 1'11
0 ~
2-16-59 63 7.2 64') 1:,o 2~ ~2 2 0
~ & ~ ¥.,a 0.1 o.~ 2') 513 235 28 ~ r.Bf o.os 0 •
.ll'PEJmIX B
HINERAL AJIALlSES or OROUtlD WATERS
IN THE VICINITY or GR0Vi1\ CITY'
(oant1Dlled)
1Toaper-1 I I f!!t.8 f!l' 1111Uon Pana l!:!r m.111on :
I &1;\&re I I 'fJ:rJ.fP I Oona'\ltllenta I I rfatiil : Tot&l. :Per- IA eqld.valenta per m.lllon I State wall I Date I vbetl I }ti l at I I I : clia- : hard- :oent l'IUllber , aampled iaampled: I 25o C t : : I I t : I I NO : f : B a s102 :aolveds nu• , Ha I °F : : C& t ~ : Na. t It : C03 : ~0.3 1 S04 1 Cl I 3 ' : : 1aol1da:{eaco:i}:
32S/l.3E-32Al ,-22-5, 68 7.6 654 ~ 22 44 2 0 102 l21f &, no o.06 0.29 26 451 n6 30 (oontinued) ~ r.Ji5 0.05 0 Tl'&' T.58
2-~o 67 7.2 ~, 58 2'/ lf8 l 0 71 ~ 51 88 o., o.o ~ lf8o 25, 2,
2.89 T.ll 2.0, o.o, 0 ~ ,. I:1ili T:li!
,-2~0 - 7.0 8'l2
~ ~ 44 / 2 0 ¥.b ~ P.ss· 50 ' 0 0.05 12 724 211 23
l.~ o;6°5 1i o:ur ---- -,...,
tJ )- 2~1 - 6.8 750 6lf
~ 42 2 0
~ l?O 56 ~ 0 0.15 2, 558 2~ 2il
I ;:m DJs o.oTi 'ti ~ ~ r.tRJ
:0
-.32D2 ,-1,-54 'l'J 7.6 813 ~ 38 28 2 0 ~ 111 2L ~ 0.2 o.o - 4~ Y/6 15
3.16 1.)2 0.05 0 5.1 2.32 1.11 0 • .38
-.32D4 12-,i-5, - 7.7 823 86
~ .30 2 0 281 112 44
~ o.4 o.o, " 526 '!IO 15
4.,o l:Ji o.(i; 0 ~ 2.,, 1.25
-.32Hl ,-5-51 6lf 8.2 1,.410 160
~ & 2 0 418 i~~ ~ .2L o., o.o, 21 '1/2 712 14
MR 0.05 0 r.85 1.,s 1.20
6-2,-57 - 7.7 1,~,
~ &, f.q; 2 0
~ ~ ~ 82 0.22 0.50 22 1,.0,2 680 15
o;m 1} ~
,-29-58 - 7.6 1,.317 r.L &a ~ 2 0
~ 260 ~ 126 0.5 0.14 30 '75 6;. 15
0.05 0 5-U; 2.03
2-16-5!1 - 7.4 l,'15 ~ ~ 48 2 0 ~ ~ 66 110 0.3 o.04 .31 1,04.3 ?15 1.3 m o.?R 'ii 1.85 r.'fi
,-22-59 65 7.0 1,567 ~ 82 &s 2 0 422 t.1o 61 fil.. o.1f2 o.;. 26 1,146 766 14 r.'i'i o.or 0 6.,i r:,! 2.01
··:.;·,:..:,.-~-;-,._:~~~ .. ;.~::.-•-~ :.,,._~f.\,,, :'.~..l.~. :~l r .;_,\,t-::~¾ ~ .. *.:,~lf .. ': ~-,. <.' 'o' ":,, 1 •, I .. .. r,~ - ........ _ __,, _____________ _
APPINDIX B
MINDU.L ANALYSES or GllOOHD WATmS
IN T1S VICINITY or C20YF.R CITY
(oontlm&ed)
:Temper-: : : Pai-ta per aiiIUon
: ature: l ilCxlo6 l Con1t1 tuents 1n parts e!r million : I I :Total : total ,P_ State well : Dde , wan : Iii t &t l equlvalenta per m1li1vn : I : dis-- 1 hard- :oent number : aampled :sampled: 1 25°- C I Ca. I ffg J Na I I: l CO I Jl:0 I s~ ~ Cl l I F : B : Sl~ :solved: nesa , Na op l I 1 : l l : ) : _3 I N03 : ; r ssol1da: !cac23~:
32S/1JE-J2Hl 10- 6-60 72 7.4 1,.355 ~ ~ &, 1 0
~ ~ &; ~ 0.5 0.05 22 1,022 591J 17
(oontinued) ~ 0
-32L2 11-11-50 - 7.5 1~010 116
~ ~ 2 - ~ ~ 1L L - 0.01 '' 653 516 1.3
5.7, 0.05 .3 l o.,, 0.05
-J.3Fl 10-21-5.3 62 8.4 1,106 136 68 116 l - 1164 231 1L 6 0.3 0.12 - 821 622 14 r.!5 5.6, 2.00 0.02 7-bO TC'S2 1.00 0.0j
lJ
l
0 "---~......,-. -
t,.~-~·- iliit\\·~-;1!~ - .. ~~,..-4-f,' ~ .. -...... -~ e. · .. Pfe-·:.~t·· ~~~) .. ~*1~~~3~~~1¥.~ =!II~ l!t'i!J&~ '$"',affl.¥.-.,;~™ ~ ..,," ·l ... ~ r·
~ .....
1femper-1 I t
: ature 1 I ECzl"' I
Da.te I when : ~ . . &t I
aaaplecl 1aampled: t 25° C I Ca t
Op ' : ' t
l~l~5!1a 71 1., 1,201
~ ,-12-6ob 76 7.1+ 1,680 4i.
m
~ per llillion
I ~ eldahl N: POa+ l
&.
b.
31 0.2 .. 11
41 15
--~·
'""' ''-- ,..
APFlll>IX C
MDmW, ANALlSiS or EP1LUEN!
ARROYO OIWIDE SEWAGE TREATIENI' PLANI'
Paris 2!!: llibion l
Con1tUuent.1 1n pu'W P8I" llilllon t I I tTote.l t Total tPer- equ1nl.enu par llilllon I t I I dia~ I mrd- IOent : I 1 CO I lllO : soi. : c1 . I , I B a s102 1aolncl1 nue r Na ~ Na I . N03 t r : : ' : ' : I : 1 :aolichu (caco3)t ~ ¥.to ~~32
0 ~ 164
0 'Pi! ¥.u 0
0 O.?l o.lt6 - ,a.a 3'8 "
& m.. 16 0
~ a t& 0 0 o.lJ 26 '//6 ))5 5,
10.30 o.41 0 0
.. ·~ .
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