About Bayshore Sanitary District
The Bayshore Sanitary District (District), one of San Mateo County’s oldest local government agencies, was formed in 1925. The sanitary district and the Bayshore School District are the two remaining local community government agencies that exist since annexation to Daly City in 1963.
Currently most of the District’s collection system and customers are in Daly City; however, the Carlyle Pump Station (CPS) and force main that discharges the collected wastewater are located in Brisbane. There are relatively few customers in the Brisbane and they are all industrial/commercial.
The principal assets of the District are:
- The wastewater collection system
- The Carlyle Pump Station (CPS)
- The force main from the CPS to San Francisco
Wastewater treatment is provided by San Francisco at their Southeast Wastewater Treatment Plant. The District has an agreement with San Francisco that sets out the terms and conditions for the wastewater treatment and associated fees. This current agreement is in effect until July 31, 2025.
The District maintains an inventory of all sewer lines within the District. The oldest lines in service date back to 1925 and are located along Geneva and Tunnel Avenue, and are still serviceable. The majority of lines are much newer and only 24% of the sewer lines are over 50 years old. The older lines are predominately vitrified clay pipe (VCP) and the newer lines are poly-vinyl chloride (PVC). The current District Standards specify PVC AWWA C900 for both the mainline and laterals.
The Carlyle Pump Station (CPS) and force main were constructed in 1972. The pump station contains 4 Worthington Pumps. . These pumps are rated at 1700 gpm at 35 feet of head.
The motors for these pumps are 30 HP motors operating at 1150 rpm. The pump station building also houses the Board meeting room and a garage for District vehicles. The CPS has been carefully maintained and it continues to function as designed. Pumps have been refurbished as required and the electrical and control components upgraded. A soil bed scrubber was added for odor control.
At the same time the CPS was constructed, a 14-inch asbestos-cement (AC) force main was constructed. This force main is approximately 3300 feet long and extends from the Carlyle Pump Station along the Old Bayshore Highway to its intersection with Sunnydale Ave. At this point, the domestic sewage from the District is discharged into the collection system of San Francisco.
The District has an exceptional database of historical flows that includes over 25 years of daily pumped flow data from the CPS. Currently the dry weather (July, August, and September) is approximately 260,000 gallons per day. As is typical with nearby older wastewater collection systems the wet weather flow increases during rainfall events. Typically the wet weather flow increases to 300,000 to 400,000 gallons per day. On rare occasions the maximum daily flow can exceed 2,000,000 gallons per day. The CPS is capable of handling this peak flow.
Not all of the wastewater is pumped to San Francisco, some wastewater enters by gravity. The total annual flow reported to San Francisco for billing purposes in 2015-2016 was 139,624,142 gallons. Of this total 109,720,000 gallons was pumped through the CPS and 29,904,142 gallons was discharged by gravity.
The District serves a total of 1457 parcels; 1329 parcel are residential and 128 parcels are non-residential including the Cow Palace and PG&E’s Martin Service Center. The residential parcels contain 1588 living units as some parcels are multi-family. The total residential population of the District is approximately 5,200.
The District is almost completely developed, but there is some in-fill development and redevelopment of existing structures. There are two large underdeveloped parcels in the District, the Geneva Drive-in/Cow Palace properties and Brisbane Baylands. There are no current plans for the Geneva Drive-In/Cow Palace parcels. The Brisbane Baylands project is currently undergoing environmental review and its status is unknown at present.
The District has carefully managed their assets and has made repairs and upgrades as necessary. Since Fiscal Year 2010-11 the District has responded to 70 service requests. A majority of those calls were related to individual laterals and 6 were reportable mainline events. There were no mainline overflows in Fiscal Year 2015-16.
The District has established various programs to manage their assets, they include:
Preventive Sewer Line Maintenance: Mainline sewers are inspected and cleaned on an annual basis to prevent stoppages and sanitary sewer overflows.
Lateral Corrective Maintenance
The District policy is to maintain your sewer lateral in the public right-of-way if your residence or business has an approved cleanout located at the property line. If you experience a problem, contact the District. A crew will be dispatched, and if it is a District responsibility, we will take corrective action to remedy the problem.
All new sewer line installations and repairs are required to meet the District’s Standard Specifications. A field inspection by the District Inspector is required during installation. Prior to acceptance by the District, a video inspection of the line is performed.
Sewer System Evaluation
Testing methods such as television inspection, flow monitoring, smoke testing and other methods, allow the District Engineer to analyze the data to develop a master plan. The District utilizes this data to correct deficiencies within the sewer system before they create a serious problem, as well as for planning for future needs and capital improvement projects.
Capital Improvement Projects
Beginning in 1985, the District implemented an extensive program to replace old, broken and undersized sewer lines. Since 1985, the District has installed new or rehabilitated sewer lines in about sixty five percent of the District. We have updated the Master Plan and are planning more sewer replacement including residential laterals from the cleanout to the mainline sewer. The District has also made significant upgrades to the CPS. The effluent flow meter and pump station valves have been replaced, and the standby generator which is 45 years old is scheduled for replacement in 2017. These projects have been funded on a pay-as-you-go basis and future projects will be funded in the same manner.
Preventive Pump Station Maintenance
Carlyle Pump Station located at 36 Industrial Way in Brisbane, was built in 1972. The majority of the District’s wastewater flows into this station and is pumped to the City & County of San Francisco’s southeast treatment plant where it receives secondary treatment. The District Board has set an aggressive maintenance policy for the station. The station is inspected on a daily basis for proper operation and scheduled maintenance is performed. This approach has resulted in the station operating at full efficiency.
In order to maintain these valuable assets and to pay for the costs of treatment by San Francisco, revenue is derived from several sources. For the last fiscal year (FY 2017-2018), revenue was derived as shown in the following table.
User fees are explained in detail in Chapter 6 of the District Ordinance. The annual sewer charge can be summarized as $125 + $5.00 x annual volume of non-irrigation water used. For a typical single family, using 200 gallons per day, the annual charge is $612.97. That rate was set in 2010 and found to be sufficient for five years. It is now anticipated that there will be no increase until 2020.