It is required of water systems to have a flushing program to ensure that the chlorine level in the water supply system is sufficient to kill bacteria and provide fresh water.
The flushing frequency depends on the characteristics of each water system such as source of water, treatment, configuration of pipes, flow/use, and time of year (temperature).
The proposed CWPF upgrades include granular activated carbon (GAC) filters, which is widely recognized as one of the best available treatment technologies for removing volatile organic compounds (VOCs), including Benzene as well as for improving aesthetic qualities of ground water by removing the naturally occurring sulfides present in ground water. The upgrades will allow for decreased chlorine demand and increased production and storage capability. The design for the upgrades also includes additional treatment at the finished water effluent (just prior to release into the distribution system) as a redundant measure to ensure water provided to our customers continues to meet and exceed water quality standards. (Updated 08/2019)
The City’s water system is currently receiving water through its multiple pre-treated imported water connections at various points in the City. Redundancy equals options, which is critical during dynamic emergency situations, and the City maintains (2) imported water connections with Metropolitan Water District with unlimited flow restrictions as well as (3) redundant emergency interconnections with neighboring water systems to ensure water source availability in an emergency situation. Although water treated elsewhere and imported into the City is more expensive than water produced and treated locally, the City is better able to ensure the quality of water our residents receive while CWPF is offline by meeting demand through our MWD connections. As CWPF is upgraded to address the recent benzene intrusion, the City will return to normal blending operations and add the additional layer of redundancy back into our water system while at the same time improving the overall quality of water received by our residents. (Updated 08/2019)
The Cypress Water Production Facility (CWPF) – which includes the Well No. 5 and the Cypress reservoir – is currently off-line due to a detection of Benzene in the City’s groundwater source. CWPF is designed to treat ground water produced from Well No. 5, blend it with imported water and transfer it into the Cypress Reservoir for storage prior to being distributed out into the water system. This generally allows for a cycled operation of the production, treatment and storage processes (i.e. produce, treat, fill, draw down, produce, treat, fill, draw down, etc.) and provides additional redundancy in the case of an emergency where additional water capacity may be needed. Because the City is currently meeting its service demand through our multiple pretreated imported water connections at various points throughout the City (rather than drawing water from the well site at CWPF and treating it on site before distribution), the Reservoir is currently not in use. (Updated 08/2019)
As an immediate response, the provision of water from the approved back-up source will mitigate any further exposure. Also, the City has recently completed the design of a Granular Activated Carbon (GAC) filtration system for the Cypress Water Production Facility to improve aesthetic qualities of the City’s water system, and has budgeted for construction of the project in the coming fiscal year. Although the City could not have foreseen the benzene contamination, GAC filtration is also widely recognized as the best-practice method of addressing and removing benzene, and the City has already begun the process of increasing the design scope of the project to accommodate for benzene removal. The City will also continue to work with our partners at the State level to identify the source of the benzene and mitigate any continued contamination. Once complete, the GAC project will allow the City to return to normal operation of Well No. 5 and continue to provide a safe, clean, and reliable source of local water supply.
The City first learned about possible elevated traces of benzene in Well No. 5’s water supply on May 9, 2019 when it received preliminary results from a regular water quality sample collected on April 30, 2019. Per State procedures, the City immediately conducted a confirmation sample and expedited the testing to confirm. The City and supporting agencies worked as quickly as possible to complete testing within seven days of obtaining the initial results. Per the Centers for Disease Control and Prevention (CDC), the adverse impacts of benzene exposure typically require continued exposure over a year or more at levels higher than what was recorded during the water quality tests. Given the relatively short time period between the first test and final confirmation of test results, as well as the relatively low levels (below the federal maximum contaminant level), the City does not believe there is any danger to the health or safety of the public.
On May 9, 2019, the City received results from a single annual water quality test sampled on April 30, 2019 that showed higher-than-usual levels of benzene. In compliance with state water quality procedures, a second confirmation test was arranged to confirm the finding. After the additional testing from an independent laboratory analysis and confirmation of the results, the City transitioned its water supply to the approved back-up supply through Metropolitan Water District (MWD) on May 15, 2019.
While there is no immediate threat to health or safety, the City is working closely with the California State Division of Drinking Water, the L.A. Regional Water Quality Control Board, and other agencies to identify the potential source of benzene contamination through extensive testing. This testing may include identification and investigation of potential sources both inside and outside the City, extensive sampling, boring and monitoring of likely sources in the area, and ongoing monitoring of soil and water levels. It may take some time to find evidence of where the problem is. The City will then receive guidance from our State partners on how to address the issue. Throughout the process, the City will let the public know of progress through LomitaWater.com and other City communication channels.
Benzene was first detected at the groundwater well (Well No. 5) located at the Cypress Water Production Facility (CWPF) at 26112 Cypress Street. On May 9, 2019, the City received a result for a single annual water quality test sample collected on April 30, 2019 that showed benzene detection over the maximum contaminant level (MCL) at 3.2 parts per billion (ppb) in the water supply at Well No. 5. Between May 9 and May 15, 2019, the City then tested at multiple points throughout the City’s treatment and distribution systems. Test results confirmed benzene was detected at 3.6 ppb and 3.7 ppb at Well No.5, and from Not Detected (ND) to 1.4 ppb in the distribution system.
On May 9, 2019, the City received a result for a single annual water quality test sample collected on April 30, 2019 that showed benzene detection over the maximum contaminant level (MCL) at 3.2 parts per billion (ppb) in the water supply at Well No. 5. Lomita Water operators conducted additional confirmation sampling at Well No. 5 and sampling throughout the City’s distribution system to verify the results. Benzene was detected at 3.6 ppb and 3.7 ppb at Well No.5, and from Not Detected (ND) to 1.4 ppb in the distribution system.
