On December 15, 2005, the US Environmental Protection Agency finalized two related drinking water protection rules that will affect thousands of public water systems across the country.

Long Term 2 Enhanced Surface Water Treatment Rule (LT2 Rule)

What it is:
The LT2 rule was promulgated to reduce the risk of disease-causing microorganisms (such as Cryptosporidium) from entering water supplies.  The rule supplements existing regulations by mandating additional treatment requirements for high risk systems.

Who it applies to:
The LT2 rule applies to all public water systems that use surface water or ground water that is under the direct influence of surface water.

Compliance dates:
Monitoring starting dates are staggered by system size. The largest systems (serving at least 100,000 people) will begin monitoring in October 2006 and the smallest systems (serving fewer than 10,000 people) will not begin monitoring until October 2008. After monitoring is completed, systems generally have three years to comply with any additional treatment requirements.

EPA’s LT2 rule website: http://www.epa.gov/safewater/disinfection/lt2/index.html

Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBP)

What it is:
EPA’s Stage 2 DBP rule builds upon earlier rules that required water systems to limit the amount of potentially harmful disinfection byproducts (DBPs) that end up in drinking water.  Under this rule, systems will evaluate their distribution systems to identify locations with high disinfection byproduct concentrations. These locations will then be used as the sampling sites for compliance monitoring.

Who it applies to:
The rule applies to water systems that add and/or deliver water that is treated with a primary or residual disinfectant other than ultraviolet light.

Compliance dates:
The rule requires treatment changes by only those systems identified as having the greatest remaining risk. The first step requires systems to determine where higher levels of DBPs are likely to occur in their distribution system.  Depending on system size and the extent of needed construction, systems will begin the first year of compliance monitoring between 2012 and 2016 and must be in compliance at the end of a full year of monitoring.

EPA’s Stage 2 DBP rule website:
http://www.epa.gov/safewater/disinfection/stage2/index.html

CHA can help

CHA’s water supply professionals can help public water systems ensure they are in compliance with EPA’s new rules.  Our staff of engineers, specialists and support technicians is experienced in all aspects of water supply system planning, design, and regulatory compliance services.  Check out our water supply, treatment and distribution system experience here.

For more information, contact Vern Ingraham or Matt Abatto, P.E. at 1-800-395-0817.