Public Health and Drinking Water News Briefs – December 23rd, 2005

In the News…
Public Health and Drinking Water News Briefs

December 23, 2005

Two New EPA Drinking Water Regulations in Effect

The U.S. Environmental Protection Agency (EPA) announced that it has finalized two drinking water protection rules – one that reduces the risk of disease-causing microorganisms from entering water supplies and another that requires water systems to limit the amount of potentially harmful disinfection byproducts (DBPs) that enter the public water supply through disinfection processes. Finalizing the two rules represents the last phase of a congressionally required rulemaking strategy under the 1996 Amendments to the Safe Drinking Water Act.

The “Long Term 2 Enhanced Surface Water Treatment Rule” (LT2), increases monitoring and treatment requirements for water systems that are prone to outbreaks of Cryptosporidium. The rule requires that public water systems that are supplied by surface water sources monitor for the waterborne pathogen. Those water systems that measure higher levels of Cryptosporidium, or do not filter their water, must provide additional protection by using options from a “microbial toolbox” of treatment and management processes.

Cryptosporidium causes gastrointestinal illness that can produce serious health threats in those with weakened immune systems, including infants and the elderly. It can also be fatal in people with severely compromised immune systems, such as cancer and AIDS patients.

The second rule, “Stage 2 Disinfection Byproducts Rule” (Stage 2 DBP) strengthens public health protection for customers by tightening compliance monitoring requirements for two groups of DBPs, trihalomethanes (TTHM) and haloacetic acids (HAA5). Stage 2 DBP targets water systems that have the greatest risk for high DBPs by using more stringent methods for determining compliance. Under the rule, water systems are required to find monitoring sites where higher levels of DBPs are likely to occur and use these new locations for compliance monitoring. If DBPs are found to exceed drinking water standards at any of these new monitoring locations, water systems must begin to take corrective action.

To read the complete proposed EPA rules, please go to:

Wet Weather Policy to Improve Wastewater Treatment Proposed

A new policy for addressing peak wet weather discharges at wastewater treatment plants was proposed this week by the U.S. Environmental Protection Agency (EPA). The agency’s aim is to ensure that local governments use all viable solutions to improve the treatment of wastewater, protecting human health and the environment during very high or “peak” flow events at municipal wastewater treatment plants that are a result of significant storm events.

Many municipal wastewater treatment systems across the country experience problems during heavy rains (peak wet weather) when flows to the wastewater treatment plants exceed the plant’s biological treatment capacity. During peak wet weather, limited “diversions” around biological treatment units can help prevent raw sewage from being discharged into our nation’s waters, backing up into homes and other buildings, or damaging biological treatment units. EPA’s proposed Peak Wet Weather policy outlines the limited circumstances when these management techniques can be used and how they must be documented in National Pollutant Discharge Elimination System (NPDES) permits.

The proposed policy is substantially different from the November 2003 proposed “blending” policy. It requires that discharges still meet all the requirements of NPDES permits and that public water facility operators demonstrate that all feasible measures are used to minimize wet weather problems. It also prohibits the use of these peak flow management techniques in systems where high peak flows are due to poor system maintenance or a lack of investment in upgrades to improve treatment capacity. According to EPA, the policy is designed to provide greater national consistency while still incorporating flexibility to recognize site-specific issues.

EPA will accept public comments on the proposed policy for 30 days after publication. To read the complete EPA policy proposal, please go to:

Killing Noroviruses: A Little Chlorine Goes a Long Way

Chlorine is far more effective at killing noroviruses than previously believed, according to a recent University of North Carolina study. Scientists involved in the research confirm that even weak chlorine solutions can still be used to kill more than 99 percent of noroviruses, the chief cause of outbreaks of gastrointestinal illness around the world.

North Carolina University researchers have discovered for the first time that dilute solutions of hypochlorous acid, or free chlorine, as low as 20 milligrams per liter will completely inactivate noroviruses on surfaces such as stainless steel and ceramic tile. The dilute chemical worked in five minutes or less. In practice, this means that household bleach can be diluted by a factor of 1,000 and still provide adequate disinfection.

Noroviruses are the leading cause of viral gastroenteritis and have caused numerous outbreaks of gastroenteritis in health-care facilities, schools, food establishments, hotels and resorts and on cruise ships. The North Carolina University researchers presented their findings during the 2005 International Conference on Antimicrobial Agents and Chemotherapy in Washington.

For information from the CDC on Noroviruses, please go to:

Chemicals on Tap in New Drinking Water Survey

A recently released survey conducted by the Environmental Working Group (EWG) on everyday tap water found 141 unregulated chemicals and an additional 119 for which the U.S. Environmental Protection Agency (EPA) has set health-based limits.

EWG compiled findings from states that agreed to provide data they collected from 1998 to 2003. The data comes from nearly 40,000 water utilities, serving 231 million people. The utilities were required by federal law to report that data to consumers. However, a compiled set of data from all utilities has not been publicly available.

Currently, the EPA gathers its own water monitoring data reviews the latest research and looks at treatment methods and technology. States are also free to set their own safety standards for contaminants that may not be detected in other states.

EWG’s analysis found almost 100 percent compliance with enforceable health standards on the part of the nation’s water utilities. Under the Safe Drinking Water Act, EPA has a systematic approach to prioritize and evaluate additional chemicals for potential regulation, considering both occurrence data and health effects research.

To read the complete study, please go to:

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