Your Water

Water Quality & Environmental Compliance

Water Quality

The final quality of West Basin’s five designer waters is dictated by either regulatory permits issued by the Los Angeles County Regional Water Quality Control Board, or contractual obligations to our customers.

Permitted Qualities

Two types of West Basin’s designer waters are permitted by the Los Angeles County Regional Water Quality Control Board.

Indirect Potable Reuse: Groundwater Replenishment – Surface Application

Along with several other requirements, West Basin’s seawater intrusion barrier injection water is required to remain below 5.0 mg/L of Total Nitrogen and 0.5 mg/L of Total Organic Carbon, when divided by the maximum average Recycled Water Content in the Barrier.

Disinfected Tertiary Recycled Water

There are several requirements written into the permit for West Basin’s Title 22 Disinfected Tertiary recycled water. Among those, the Disinfected Tertiary recycled water must be disinfected such that the 7-day median of total coliform bacteria does not exceed 2.2 MPN per 100 mL. Additionally, the Disinfected Tertiary recycled water must not exceed a turbidity of 2 NTU, based on a 24-hour average.

Contractual Obligations for Industrial Users

West Basin added additional treatment technology to achieve specific water qualities certain customers require.

Nitrified Recycled Water

Three of West Basin’s large industrial customers use recycled water for refinery cooling tower applications. An additional biological treatment step is applied to the Disinfected Tertiary stream to reduce ammonia concentrations and prevent corrosion of the refinery equipment.

Boiler Feed Supply

Three of West Basin’s large industrial customers use recycled water for boiler feed applications. In this application, recycled water is used to generate steam to be used within the refining process. Additional treatment steps, including microfiltration and reverse osmosis are utilized to reduce the Total Dissolved Solids and other inorganic constituents such as Total Hardness and Silica, to levels acceptable for steam generation.

West Basin produces two types of this recycled water, low-pressure and high-pressure boiler feed supplies. High-pressure boiler fed water is produced by treating the low-pressure boiler feed product with a second pass of reverse osmosis. The low-pressure boiler feed treatment system reduces the Total Dissolved Solids in the recycled water to approximately 35 mg/L, whereas the high-pressure boiler feed treatment system reduces the Total Dissolved Solids ever further, to approximately 3 mg/L.

Water Quality Reports

West Basin takes our responsibility to provide safe, high-quality water to our customers seriously and intentionally. Our water quality exceeds state and federal drinking water standards. As a wholesale agency, West Basin does not conduct water quality tests on potable water but monitors Metropolitan Water District’s (MWD) testing and reporting. View MWD’s water quality reports or visit www.mwdh2o.com.

Since 1991, California water utilities have been providing information annually on water served to its consumers, according to state law. A 1996 federal law similar to California’s also required water utilities across the country to provide information to their consumers on the water served. The reports describe the water quality, sources of water, and other information to inform consumers on their water supply. For more information, contact your water provider for details on the annual consumer water quality report.

Environmental Compliance and Stewardship

West Basin Municipal Water District (West Basin) is committed to environmental and regulatory compliance for all its water operations. The Regulatory Compliance Division of the Technical Resource Department manages over two dozen compliance permits related to air quality, hazardous material management, waste disposal, new project development, storm water runoff as well as strict water quality control permits. Deviation from permit requirements can result in heavy fines as well as criminal prosecution in extreme cases. Continuous and extensive reporting is managed for West Basin by the Regulatory Compliance Division staff.

Permitting

Product Waters

California’s Recycled Water Policy is intended to increase the use of recycled water from municipal wastewater sources that meets the definition in Water Code Section 13050(n), in a manner that implements state and federal water quality laws. When used in compliance with the Recycled Water Policy, water recycling criteria in Title 22 of the California Code of Regulations, and all applicable state and federal water quality laws, the State Water Board finds that recycled water is safe for the approved uses. The State Water Board strongly supports recycled water as a safe alternative to potable water for such approved uses.

  • Indirect Potable Reuse: Groundwater Replenishment – Surface Application

Requirements for the type of Potable Reuse implemented by West Basin are identified in California’s Water Code of Regulations, Title 22, Division 4, Chapter 3, Article 5.1.

  • Disinfected Tertiary Recycled Water

Requirements for recycled water use in irrigation are identified in California’s Water Code of Regulations, Title 22, Division 4, Chapter 3, Article 3.0.

  • Waste Discharge

West Basin hold several sewer discharge permits for various streams including neutralized cleaning chemical solutions, sample analyzers streams, or filter backwash waste.

  • Biosolids
  • Brine Discharge

Quarterly Compliance reports are submitted to both the Los Angeles Regional Water Quality Control Board and the Environmental Protection Agency.

  • Air Quality Management District

Energy Efficiency

Greenhouse Gas Emissions Inventory

In 2008, West Basin became a member of both the California Climate Action Registry and The Climate Registry (TCR). These organizations were established to assist entities with voluntarily reporting their greenhouse gas emissions. When the California Climate Action Registry dissolved, TCR became the sole reporting entity for greenhouse gas emissions. West Basin has reported its emissions since 2008. The inventory can be found on the TCR Website.

In addition, State regulations such as AB 32- The Global Warming Solutions Act, has encouraged staff to closely monitor its development and to prepare West Basin for possible future greenhouse gas reduction mandates.