Wastewater FAQ

General Wastewater

East Bay Municipal Utility District supplies homes with clean water, whereas CVSan is responsible for the collection and treatment of wastewater.
A collection system is a network of pipes, manholes, clean-outs, lift stations and other structures used to collect all wastewater and transport it to a treatment plant or disposal system. CVSan is a collection system only. Treatment and disposal take place at the Castro Valley/Oro Loma Wastewater Treatment Facility in San Lorenzo.
Sanitary sewer systems are the collection of pipes, pumps and lift stations, manholes, service lines, and other infrastructure throughout the District designed to handle and safely transport used water, body wastes, and toilet paper as sewage to a treatment plant.

Sewer Overflow/Backup

Contact CVSan immediately to report a sewage overflow. To contact CVSan during normal business hours (Monday – Friday, 7:00 am - 4:00 pm), please call (510) 537-0757. For after hours (weekdays between 4:00 pm – 7:00 am and weekends) please contact CVSan on-call personnel at (510) 506-5821.
When a backup occurs, contact CVSan’s Main Office at 510-537-0757 during business hours (7:00 a.m.-4:00 p.m. Mon-Fri) or (510) 506-5821 after hours.

CVSan will assess the backup to determine if the blockage is in the public sewer line or the property owner’s private sewer lateral. CVSan will clear blockages that occur in the public sewer line only. Property owners are responsible for blockages that occur in their private sewer lateral, located within two (2) feet of the foundation wall of the building and extending to and including the connection to the public sewer line.

If it is determined that the public sewer line is blocked, only CVSan has the authority to clear the system. If the public sewer line is clear, the District’s representative may advise the property owner to contact a plumbing contractor to perform maintenance to their private sewer lateral.

Most sewer backups happen because the line is plugged with an obstruction. However, backups can be caused by several factors including the condition of the sanitary sewer system itself, natural phenomena such as earth movement, heavy rainfall, and the incorrect usage of the system by the public.

Some common backup causes are:

- Solids / debris – Typical solids that buildup in the pipe and cause backups are dirt, hair, bones, tampons, paper towels, kitty litter, diapers, broken dishware, garbage, concrete, and debris.

- Fat/Oil/Grease - When fat, oil or grease is discharged into a sewer system they will solidify and, after a while, can build up and plug drain lines in your building or complex. They can also plug the sewer lines owned by the District, thus increasing the maintenance cost to the District. Plugged sewers can also cause flooding of nearby private homes and businesses.

- Tree Root infiltration – Tree roots can cause backups. Roots can infiltrate the pipe system and block the wastewater flow.

- Water inflow/infiltration – Rainwater entering the public sewer line can cause system problems and overflows. If the sanitary sewers only transported wastewater, backups would only occur when obstructions were present in sewer pipes. However, during certain wet weather conditions, sanitary sewers can become overloaded with groundwater or storm water runoff so they become surcharged or overloaded. This results in backups into lower levels and basements, or slow running services.

- Structural defects in pipes and manholes – Significant sags, bellies in the line, cracks, holes, protruding laterals, misaligned pipe, offset and open joints and collapsing pipe material are all possible causes of backups.

Sewer Service Charge

The purpose of the sewer service charge is to raise revenue to fund the cost for maintenance and operation and for renewal and replacement of the facilities necessary to collect, treat and dispose of wastewater generated from your home or business to ultimate deep-water discharge into San Francisco Bay.
The District uses the Alameda County Tax Rolls as the primary method of collection of the Sanitary Sewer Service Charge on an annual basis. This line item shows up on the property owner’s property tax bill under the Special Assessments section.
The District has one of the lowest rates in Alameda County and lower than the average annual charge in the State of California.

Manhole Lids

The manholes circular metal lid usually located in the middle (sometimes to the side) of the roadway are for access to the sanitary sewer pipe. Only authorized District personnel can remove the manhole. Unauthorized entry into manholes is extremely dangerous and strictly prohibited.
Please call CVSan immediately.

Monday – Friday, 7:00 a.m. - 4:00 p.m.
(510) 537-0757

After Hours
(510) 506-5821

Fats, Oils, and Grease Control Program

Sewer capacity constraints are frequently caused by improper materials, including fats, oils, and greases being introduced into the sewer system by District residents and businesses.
From 50–70 percent of all sanitary sewer system problems overflows are caused by accumulations of fats, oils and greases discharged to it from the preparation and serving of food.
Many sources. In the food industry, "grease" often refers to fats and oils derived from animal and vegetable sources. These include meats, nuts, cereals, beans and waxes/paraffins.
Grease removal devices are outdoor Gravity Grease Interceptors (GGI) or indoor Grease Removal Devices (GRD) for non-residential use. They are designed, constructed, and intended to remove, hold, or otherwise prevent the passage of FOG into the public sewer mains.
Any FSE that introduces FOG into the public sewer main in quantities large enough to cause line blockages or hinder wastewater treatment is required to install a grease trap or interceptor.
Yes. The reason you need a grease trap or grease interceptor is because of the cleanup, not the cooking. When you wash your cooking equipment, you are washing fats, oils, and grease (not to mention solids) into the public sewer main. It’s the fats, oils, grease, and solids (foodstuff) that damage public sewer mains.
It is recommended that, all grease removal devices should be maintained regularly so that the depth of floating FOG and settled solids accumulation do not exceed 25% of the hydraulic length, at any time. Thereby, the working depth of each device stays more than 75% for effective FOG separation. All grease removal devices shall be maintained to ensure compliance with CVSan’s discharge limits for oil and grease in accordance with CVSan Code Section 6206. As per CVSan Code Section 6216, the minimum cleaning frequency required for all grease interceptors is 6 months. Some establishments will find it necessary to clean their interceptors more often than what is required by the Code.
The California Plumbing Code requires that no grease trap have a capacity of fewer than 20 gallons per minute (gpm). The size of the trap depends upon the number of fixtures connected to it. The size will also depend upon the maintenance schedule. If a grease trap or interceptor is not maintained regularly, it will not provide the necessary grease removal.
The small under-the-sink or under-the-counter traps that are usually located inside the building may be cleaned by the establishment itself. It is recommended that if cleaning is performed by kitchen staff, solids and FOG should be dewatered and discarded in the trash. The large outside interceptors must be cleaned by a licensed grease hauler. This is due to the volume of waste contained inside the trap and the proper disposal of this waste. The interceptors are roughly the size of a residential septic tank and they are confined spaces. No one is allowed to enter confined spaces without training or certification.

List of Grease Haulers for Alameda County


A-1 Septic Tank Service

(510) 697-8083

A-1 Septic Tank Service

(800) 730-4471

All Valley Environmental, Inc.

(559) 498-8378

Able Septic

(408) 377-9990

Ameriguard Maintenance Services

(800) 347-7876 ext 14

Bay Area Restaurant Services LLC

(888) 994-0753

Bay Pumping

(831) 320 5229

Burr Plumbing & Pumping

(408) 287-2877

Darling International

(800) 473-4890

Evergreen Recycling, Inc.

(650) 952-5000

Interstate Restaurant Services

(844) 434-4343

Liquid Environmental Solutions


Magnum Fire Protection

(510) 742-0775

Miller & Gibson (prev Able Septic Tank Service)

(408) 377-9990

Miller & Gibson (prev Able Septic Tank Service)

(408) 398-4990

ModestoTallow/Florin Tallow Co.

(209) 522-7224

ModestoTallow/Florin Tallow Co.

(800) 564-7204

One More Time

(800) 624-5504

Pioneer Liquid Transport

(800) 804-7327

Portosan Santa Rosa

(707) 566-2000

Rescue Rooter

(800) 869-6917

Roto Rooter

(800) 269-3747

Sacramento Rendering Co.

(800) 339-6493

Salinas Tallow

(800) 621-9000

San Jose Tallow

(408) 452-8777


(800) 447-3794

This list is not comprehensive, nor does it endorse any company. This is provided as a reference only.

According to California Food and Agricultural Code Sections 19310 and 19311, a Licensed Grease Hauler is a person who is registered with the department of Food and Agriculture as a transporter of inedible kitchen grease and who is in possession of a valid registration certificate from the Department of Food and Agriculture. Licensed Grease Haulers are eligible to operate vehicles for the purpose of collecting inedible kitchen grease that includes used cooking/fryer oil. They are also eligible to clean the grease traps and grease interceptors.

Do not pour yellow grease down the drain or in the trash. It is best to compost small amounts of cooking/fryer oil (in a paper milk or ice cream carton). Large amounts of cooking/fryer oil should be collected in a separate recycling bin or container set up either inside or outside the building and hauled through a licensed grease hauler. Large amounts of used oil can also be transported by the food facilities in their own vehicles to the central collection point.
It is best to compost small amounts of grease scraped from traps and cookware (in a paper milk or ice cream carton). The grease from traps and cookware should not go into the used oil recycle storage bin. Brown grease should not be mixed with yellow grease unless the yellow grease hauler can recycle the entire contents when they are mixed. Large quantities of brown grease should be disposed of through a local cooking oil and grease recycler.
The food service establishment should install and maintain appropriate grease removal devices, as per CVSan Codes and follow all the ‘Best Management Practices’ (BMPs) of the District.


An Easement is a legal document that conveys limited property rights from the Grantor (Property Owner) to the Grantee (Castro Valley Sanitary District). This document is usually recorded in the office of the Alameda County Recorder. A sanitary sewer easement creates a non-exclusive, perpetual right to use a portion of your property for sanitary sewer purposes. This provides the District with access rights to repair, replace, inspect, enlarge, change, maintain, test and/or remove the sanitary sewer located within the easement.
The Property Owner continues to own the land and has only given up defined rights on the portion of land used for the easement. Maintenance of the property within the easement is the responsibility of the Property Owner.
The easement is typically ten feet wide (five feet on either side of the sanitary sewer), however, the size may vary. The location will be determined from recorded maps or a grant of easement document. If you are unfamiliar with the size and location of your easement please contact your title company or the District at (510) 537-0757.
The District, if it has an easement, may go onto the easement at any time. The District may, on occasion, have a Contractor present to perform specific tasks relating to the District's operations. We will make an effort to notify you prior to entry, however, in the case of an emergency, we may need to enter without prior notification. Please request, at any time, to see District personnel photo identification cards, or contact the District at (510) 537-0757.

Do you have a dog?

The District makes every effort to try to minimize impacts on you, however, if you own a dog this makes our work a little more challenging! We would appreciate it if you could provide us with your name and contact number so we can make special arrangements with you regarding the care for your dog before entering your property. Please contact us at (510) 537-0757.
An easement is typically granted to the District with the understanding that the property owner may make improvements to the surface such as fences, asphalt paving, trees, irrigation and lighting systems or similar improvements. As part of the agreement, the District is permitted to remove any of these improvements for the purpose of maintaining and/or replacing the sanitary sewer. Please note that the District is not liable for any damage to your improvements.

Do not place planters or any other objects on manhole covers.

Fences and gates are not to be constructed over manhole covers.

No permanent structures are to be erected within the easement location.

Keep the location of the easement clear of debris and material, especially around manhole access points.

Planting of trees within the easement is not permitted without prior approval from the District.

For more information on keeping the area clear within the easement, please contact the District at (510) 537-0757.

An encroachment is a physical intrusion in an area of the easement contrary to the agreement. The District may require that any unauthorized encroachments be removed at the property owner's expense. All encroachments on easements require written approval of the District by way of an Encroachment Agreement.
The property owner may be faced with all costs of removal and any associated damages resulting from unauthorized structures or improvements on land subject to an easement.

Lateral Replacement Grant Program

Property owners can download an application online,  pick one up at CVSan's Main Office at 21040 Marshall Street, Castro Valley, or request a copy be mailed or e-mailed by calling (510) 606-1300. Please note that the property owner is responsible for obtaining an application.
Property owners can download an application online on Lateral Replacement Grant Program Page, or pick one up at CVSan's Main Office at 21040 Marshall Street, Castro Valley, or request a copy be mailed or e-mailed by calling (510) 606-1300. Please note that the property owner is responsible for obtaining an application.
You obtain price quotations from contractors listed on CVSan’s Qualified Contractors List (QCL).
The property owner is required to obtain and submit a minimum of three price quotations.
Legally, CVSan may not recommend any contractors; however, CVSan does require work for the LRGP to be completed by a contractor listed on CVSan’s QCL.  CVSan’s QCL is comprised of contractors who have worked in CVSan’s boundaries and been thoroughly vetted. Only contractors listed on CVSan’s QCL are eligible to provide valid price quotations for submission and to complete work through the program. For a copy of CVSan’s QCL, please contact (510) 606-1300.
Please inform CVSan immediately if you are experiencing any difficulties with a contractor.
While each contractor is allowed to write a price quotation with as little or as much information as they choose, CVSan will review each price quotation with the property owner and inform them it is in their best interest to request a revised quotation from the contractor if the following pieces of information are not listed on the submitted price quotation:
i. The total cost of lateral repair/replacement.
ii. The cost of wye or tap, should it need to be replaced.
iii. If the total cost of the lateral repair/replacement includes CVSan’s Repair/Replacement Permit.
iv. If the total cost of the lateral repair/replacement includes Alameda County Public Works’ Encroachment Permit.
Written price quotations need to be submitted to CVSan office personnel, along with the completed application. Contractors and CVSan field personnel cannot accept or submit applications or price quotations for the LRGP.
A Condition rating is an assessment of the private sewer lateral to determine the degree of defects to the lateral. Condition ratings take into consideration: pipe cracks, roots, water infiltration evidence, and other defects. Each defect is given a numerical designation (this is similar to the method used on the public sewer main). Property owners with laterals receiving a poor condition rating may receive grant funding.
Property owners will know they have qualified for the LRGP when they receive a Letter of Approval from CVSan stating that they have qualified and funds have been obligated for your project.
Yes, property owners will need a repair permit from CVSan to perform lateral repair/replacement work. You may also need an encroachment permit from Alameda County Public Works if you are doing work in the public roadway.
After you receive your Letter of Approval, select one of the contractors from whom you have received valid price quotations to commence work. You will have 90 days in which to complete construction, inspection, pay the contractor in full, and submit a copy of your “Paid-In-Full” invoice to CVSan. Please note, it is the property owner’s responsibility to ensure the contractor has been issued all necessary permits for the job prior to work commencing.
CVSan requires two site inspections: one that the property owner schedules with CVSan personnel to witness the contractor recording your lateral with a camera; and one that your contractor schedules after the new sewer line has been installed, but prior to any backfilling. CVSan personnel will witness testing of the entire line from the building foundation to the connection to the public sewer main. Testing will be performed by your contractor.
No, the initial site inspection must be scheduled by the property owner; all correspondence should be conducted between the property owner and the contractor directly, or the property owner and CVSan directly.
Once the second site inspection is complete, you need to submit a copy of your “Paid-In-Full” invoice to CVSan for the work performed. CVSan will then process your invoice for payment; payment will be made within 30 days. Please note, your “Paid-In-Full” invoice should either be stamped “Paid-In-Full” or written and initialed by the contractor that it is “Paid-In-Full.”
CVSan takes into account all written complaints from property owners about the contractors. This is a factor when deciding to remove the contractor from the program for the current year, as well when creating the eligibility list for the following years. If you would like to file a complaint about a contractor, please contact CVSan.