Water quality regulations are frequently reviewed in light of new scientific findings and development of new technologies. As improved technologies allow for the detection of contaminants at lower levels and as information on potential health effects of contaminants emerge, federal and state regulators explore the feasibility of improved or new water quality goals.
Information on recently enacted or proposed regulations will be posted on this page.
See how LADWP is addressing the problems open reservoirs pose to water quality and safety. Learn more about open reservoirs.
Long Term 2 Enhanced Surface Water Treatment Rule and Stage 2 Disinfectants/Disinfection By-Products Rule
On December 15, 2005, the United States Environmental Protection Agency (US EPA) finalized the Long Term 2 Enhanced Surface Water Treatment (LT2) Rule and the Stage 2 Disinfectants and Disinfection Byproducts (DBP) Rule. The LT2 Rule provides additional protection against disease-causing pathogens in surface water supplies. The DBP Rule further reduces the level of by-products from disinfection. Together, these rules attempt to balance the reduction of known microbial risk with potential chemical risks of byproducts from disinfection. These rules are part of a continuing process to further improve drinking water quality nationally.
Over the past 10 years, the LADWP has phased in a plan to manage and reduce DBP levels in its water supply, without compromising microbial safety, and to address the 10 open reservoirs to comply with these regulations. LADWP has successfully met the requirements of the original first phase of these Rules, which involved removing four of ten open reservoirs from service—Lower Stone Canyon, Encino, and Upper and Lower Hollywood. Water from these reservoirs no longer directly serve customers; however, these reservoirs are being maintained for emergency supply purposes as well as aesthetics. In addition, LADWP is methodically converting the remaining areas of the city from chlorine to chloramines as its secondary disinfectant. Chloramines form less DBPs than does chlorine and will further reduce DBP levels in the city’s water supply.
The newest US EPA rules makes it necessary for the LADWP to complete the system-wide conversion to chloramines and to make extensive modifications to the water distribution system, including removing the remaining six open reservoirs from service by 2011. Planning is already underway for these water quality improvement projects in conjunction with communities surrounding each of the remaining open reservoirs. See Projects, Water Quality Improvement.
In addition, the LADWP provides regular updates to customers regarding DBP levels in the city’s water system through its Web site. The Annual Water Quality Report, which is published in both English and Spanish and mailed to all customers, also informs customers of the possible risks associated with DBPs, and encourages women who are pregnant or think they may become pregnant to consult their physicians. For more information about DBPs and other constituents, as well as a map of DBP levels in the city of Los Angeles, please go to Fact Sheets and Brochures.
Total Coliform Rule
There are a variety of bacteria, parasites, and viruses which can cause health problems when humans ingest them in drinking water. Since testing water for each of these germs would be difficult and expensive, water agencies measure the presence of bacteria in drinking water by using coliform bacteria as an indicator. The presence of any coliforms in drinking water suggests that there may be fecal pathogens in the water.
With the implementation of the Total Coliform Rule (TCR), there has been a reduction in the risk of illness from disease causing organisms associated with sewage or animal wastes. Disease symptoms may include diarrhea, cramps, nausea, and possibly jaundice, and associated headaches and fatigue.
The TCR (published 29 June 1989/effective 31 December 1990) set both health goals (MCLGs) and legal limits (MCLs) for total coliform levels in drinking water. The Maximum Contaminant Level (MCL) is based on the presence or absence of total coliform bacteria, including fecal coliforms and Escherichia coli (E. coli).
All public water systems are required to comply with the TCR. However, the monitoring and compliance requirements vary depending on the size of the community water system. The TCR requires the use of a routine sample siting plan, outlines the type and frequency of monitoring and testing that water systems must do. A sanitary survey (for systems collecting fewer than five samples per month) may also be required.
The United States Environmental Protection Agency (US EPA) is in the midst of a significant effort to revise the TCR. The Total Coliform Rule Distribution System Advisory Committee (TCRDSAC) was established by the US EPA to provide advice and make recommendations on revisions to the TCR.
On September 18, 2008, members of the TCRDSAC signed an Agreement-In-Principle (AIP) that recommends revisions to the 1989 TCR, as well as research and information collection needed to better understand potential public health impacts from conditions in the distribution system. The AIP calls for the formation of a Research and Information Collection Partnership (RICP) to inform and support the drinking water community in developing future national risk management decisions pertaining to drinking water distribution systems.
LADWP has written and implemented Bacteriological Routine Sample Siting Plans that address all the requirements of the TCR. Although total coliforms are commonly found in the source waters to Los Angeles, the LADWP continues to meet all Federal and State standards through ozone and chlorine disinfection.
Helpful Websites for More Information
US EPA's Drinking Water Regulatory Information
California State Water Resources Control Board, Division of Drinking Water (DDW)