IDEM's Letter to Public Water Suppliers Regarding Atrazine

Dear Owner:

RE:            Atrazine in Source Water at Surface Water Systems

The purpose of this correspondence is to provide some information relative to minimizing any potential risks associated with the presence of atrazine (and related triazine compounds such as simazine, propazine, sianazine, etc.) in drinking water.

The Indiana Department of Environmental Management (IDEM) has reviewed available information on levels of atrazine in drinking water source supplies during the spring season.  Based on our review, IDEM believes that, while the source water may not violate the applicable drinking water standard, levels of atrazine can be elevated and perhaps even in violation of the drinking water standard after runoff events and heavy rains.   IDEM believes that it is prudent to take available steps to minimize concentrations of atrazine in drinking water.

Accordingly, we are asking your assistance in reducing any potential impacts from atrazine on drinking water consumers.  IDEM is requesting that all surface water systems begin immediately assessing their source water for the presence of atrazine.  If atrazine is found above detectable levels in the source water, the system should provide treatment for the removal of atrazine or take other steps to reduce the level of atrazine in the finished water.  We are making this recommendation even if atrazine is detected below the Maximum Contaminant Level (MCL) of 3 ppb.  Many surface water systems in our State already routinely monitor for atrazine in their source water and provide treatment or implement other preventative measures to mitigate any atrazine found in the source water.  IDEM supports and commends these efforts.

To assist those systems that do not already monitor their source water or provide treatment for atrazine, IDEM’s Drinking Water Branch (DWB) is available to work with those systems to develop a plan and strategy to help the systems in minimizing the potential impact of atrazine on public health.  We are asking all community surface water systems to help us in this endeavor by working with us in identifying or profiling your water source for atrazine.  We anticipate some sampling for atrazine in your raw (before treatment) water if you are not currently doing so for a period of time. 

We will be contacting your system in the very near future to request the following information:  

1. Source and location of your water intake (river or reservoir);

2. Any current data for atrazine and/or triazines in your raw water;

3. If you have been monitoring for these contaminants, copies of the analysis results for a minimum of one (1) year or preferably up to three (3) years worth of information.  Some systems may have done the testing in conjunction with the manufacturer of atrazine and/or triazine in the past, we would appreciate obtaining copies of those analytical results as well;

4. Information on whether your public water system provides treatment to your source water using granular activated carbon (GAC) or powdered activated carbon (PAC);

5. If treatment is provided, information on whether you treat with GAC or PAC year-round or seasonal?  If treatment is not provided, information on how you provide treatment?

After reviewing the above information, the DWB will contact you to discus the following recommendations:

• If your system does not currently monitor or have source water data for atrazine, the DWB will be recommending that your system sample for these contaminants. The DWB will help you determine what is the most viable and cost effective way for doing these tests.

• For those systems that do not routinely provide activated carbon treatment, we will recommend that the systems begin adding this type of treatment.  (Information gathered about GAC indicates that the cost per 1,000 gallons of water treated with GAC is less than $0.03 which includes regeneration costs.  This may be a very reasonable approach considering the benefits achieved.)

• For those systems that provide seasonal treatment, we may recommend that treatment be provided on a year-round basis or be based on source water analysis, since there is the potential for other types of volatile and synthetic organic contaminants in the source water.

• For systems with detectable levels of atrazine in their source water, the DWB will recommend that the system initiate and/or participate in source water protection efforts.

We look forward to working with you in our efforts to keep our drinking water safe.  If you have any questions, please contact Mr. Al Lao of the Drinking Water Branch at 317/308-3283.

Sincerely,

Matthew C. Rueff

Assistant Commissioner

Office of Water Management    

 cc:  PWS Operator

___________________________

See IKE's broader effort on pesticides for more details.