April 7, 2010 

U.S. Environmental Protection Agency 

Office of Pesticide Programs (OPP) 

Regulatory Public Docket (7502P) 

1200 Pennsylvania Ave NW 

Washington, DC 20460-0001 

RE: Re-Evaluation of Human Health Effects of Atrazine 

 Docket EPA-HQ-OPP-2010-0125 

Dear Docket: 

The American Water Works Association (AWWA) is an international, nonprofit, 

scientific and educational society dedicated to the improvement of drinking water quality 

and supply. Founded in 1881, the Association is the largest organization of water supply 

professionals in the world. Our 57,000-plus members represent the full spectrum of the 

drinking water community: treatment plant operators and managers, environmental 

advocates, engineers, scientists, academicians, and others who hold a genuine interest in 

water supply and public health. Our membership includes more than 4,200 utilities that 

supply roughly 80 percent of the nation's drinking water. 

AWWA and its member utilities are dedicated to safe water and we appreciate the 

opportunity to comment on potential statistical approaches for drinking water monitoring 

frequency. Our staff and member utilities are not experts on the health effects issues and 

will leave those issues to the appropriate experts. 

However, any potential changes to atrazine compliance monitoring frequency has 

implications to our member utilities, particularly small-to-medium surface water utilities 

in the Midwest that are subject to wide variability of atrazine concentrations in their 

source water. Without re-stating the extensive literature on this issue, surface water 

utilities in the Midwest experience a spring “flush” of atrazine in their source water, and 

the magnitude and duration of this depends on several factors such as application date, 

intensity and duration of the rainfall, the timeframe between application and rainfall, and 

several other factors. In some Midwestern reservoirs, this spring “flush” will remain in 

the reservoir so that atrazine levels are elevated year-round. 

At the same time, due to its use in right-of-ways and other widespread uses, atrazine is 

ubiquitous in almost all surface waters and in many groundwaters, albeit in low 

Government Affairs Office 

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www.awwa.org

Headquarters Office 

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The Authoritative Resource on Safe Water SM
Docket EPA-HQ-OPP-2010-0125 

April 7, 2010 

Page 2 

concentrations. In a recent study by USGS, Trends in Pesticide Concentrations in CornBelt Streams, 1996-2006, out of 4,652 samples, only eight were non-detects. In other 

words, atrazine was detected in 99.8% of the USGS samples of potential sources of 

drinking water. This study did have a relatively low detection limit of 0.004 ppb and the 

samples were taken in what might be considered “vulnerable” areas. 

AWWA has been closely following the regulatory development process for atrazine, 

simazine, and the other triazines since Maximum Contaminant Levels (MCLs) were 

promulgated in the early ‘90s. Compliance with the atrazine MCL is based on an annual 

average of quarterly samples. 

Atrazine and other triazine herbicides have been a major issue for AWWA and its 

member utilities for many years, due to the potential for groundwater and surface water 

contamination from these herbicides. For more than 20 years, AWWA has written 

multiple letters to EPA and Congress expressing our concern with the impacts of 

agricultural chemicals, including the triazines, on drinking water supplies. AWWA has 

written extensive comments on EPA’s proposals as part of the atrazine reregistration 

process. AWWA has been concerned with the lack of data for making informed 

regulatory decisions, and EPA’s past Interim Reregistration Eligibility Decisions (IREDs) 

have been a step in the right direction in mandating more monitoring data paid for by the 

registrants. These registrant-monitoring requirements should be a typical component of 

the reregistration process for ANY pesticide with potential for drinking water exposure. 

AWWA has submitted several sets of comments to EPA’s Office of Pesticide Programs 

(OPP) throughout the atrazine special review and triazine reregistration processes. Our 

past comments have focused on several issues, but primarily, our main concern is the 

ongoing additional treatment burden that our utility members, and ultimately their 

customers, will have to pay in order to comply with the drinking water standards, 

primarily the current atrazine standard. Many surface water utilities installed additional 

treatment (either Granular Activated Carbon or Powdered Activated Carbon) soon after 

the MCL was finalized in 1991 to comply with this new standard. The registrant and the 

growers have made some progress in controlling atrazine at the source, and this 

stewardship, combined with the additional carbon treatment by utilities, have contributed 

to atrazine violations decreasing from 81 in 1995 to 3 in 2007. But keep in mind 

violations are based on finished drinking water, as opposed to the drinking water sources 

in the USGS study previously mentioned. 

EPA’s recent release of finished water monitoring data from 44 states as part of its sixyear review of drinking water regulations (75 FR 15500) basically parallels the above 

violation data. Atrazine was detected in 4.23% of 161,690 samples. The median, the 90th

percentile, and the maximum concentrations in this dataset ranged from 0.1-1.61 ppb, 

0.1-4 ppb, and 0.1-27 ppb respectively. Generally, atrazine is found less frequently in 

finished drinking water as opposed to drinking water sources due to existing treatment to 

comply with the atrazine MCL. 
Docket EPA-HQ-OPP-2010-0125 

April 7, 2010 

Page 3 

However, AWWA believes that additional regulatory actions (sooner rather than later) 

are necessary so that drinking water utilities (and their customers) are not continued to be 

saddled with the additional costs of carbon treatment. EPA’s regulatory actions should 

be geared towards moving the costs from the utilities’ customers to the atrazine 

registrants and users. 

To better understand triazine occurrence patterns and the relationships between the parent 

compounds and their degradation products, the Water Industry Technical Action Fund 

(WITAF) funded two extensive research efforts in 2003 and 2004. The 2003 monitoring 

program was conducted at 38 plants using the EPA-approved Beacon/Syngenta 

immunoassay (IMA) analytical method as the primary analytical method. Dr. Craig 

Adams of the University of Missouri-Rolla (UMR) developed a GC-MS analytical 

method for the triazine parents and their degradation products. UMR also conducted 

treatability studies through separate funding from the Missouri Department of Natural 

Resources (DNR). All of the utilities monitored weekly from March to September by 

collecting samples and shipping them to the University of Colorado-Boulder (CU) for 

IMA analysis. A smaller subset, consisting of 14 utilities, conducted both weekly (IMA 

at CU) and daily monitoring (IMA onsite). Approximately 10% of the samples collected 

by both the daily and weekly samplers were sent to UMR for GC-MS analysis. 

Information on treatment practices and source water quality were collected at the same 

time as the samples. 

In April 2003, problems with the Beacon/Syngenta IMA analytical method became 

apparent. Interferences from chlorine, chloramines, chlorine dioxide, Total Organic 

Carbon, and other compounds were investigated at UMR. Since this project was not a 

method validation project, all of the potential interferences were not investigated. 

However, it is clear that this IMA method is precise but not accurate, and generally 

biased high. The lack of robust IMA method performance was also confirmed by EPA’s 

Environmental Technology Verification (ETV) program conducted by Battelle in 2004. 

This IMA method can be used for screening but is not accurate enough for drinking water 

compliance monitoring and that is important due to the higher cost of compliance 

monitoring using the approved analytical methods. 

The 2004 monitoring program was conducted at 49 plants. This project was a partnership 

between the Water Industry Technical Action Fund (WITAF) and the Awwa Research 

Foundation (AwwaRF, now the Water Research Foundation). Monitoring was again 

conducted in the March-September timeframe and analysis was conducted using the 

Abraxis IMA method at the offices of McGuire Environmental Consulting. Again, 

approximately 10% of the samples were split and analyzed for triazine parents and their 

degradation products using GC-MS at UMR. The 2004 IMA monitoring data show some 

improvement compared to the 2003 data, with the results being precise but not accurate, 

and generally biased slightly high. Monte Carlo analyses were conducted to understand 

the potential compliance impacts from different compliance sampling regimes (biweekly, monthly, quarterly, etc.), but it became apparent that more than one year of 

monitoring data was needed to analyze potential regulatory compliance monitoring 
Docket EPA-HQ-OPP-2010-0125 

April 7, 2010 

Page 4 

options. A listing of the six peer-reviewed publications that have resulted from this 

research effort is enclosed at the end of these comments. 

Our latest effort is a statistical analysis of the multiple years of Syngenta monitoring data. 

As previously mentioned, it became apparent from the previous research that more than 

one year of monitoring data was needed to better understand source water variability and 

to analyze potential monitoring options. Syngenta provided our contractor, Clancy 

Environmental Consultants, with their monitoring data from 1993 to 2005 in order to 

conduct a more robust statistical analysis. This analysis focuses on developing a high 

confidence that measured values do not exceed the specific values established in a 

regulation (whatever those values might be). This project has found that the number of 

samples needed to characterize the “spring flush” and understand its potential impacts on 

compliance with a specific value varies depending on the mean and standard deviation of 

the monitoring data. These potential monitoring requirements can be very clearly and 

succinctly summarized. The results from this analysis suggest that using historical data, 

sampling can be designed so that surface water systems that are “vulnerable” with high 

means and high variability need to sample more frequently while systems that have low 

means and/or little variability do not need to sample as frequently. 

The economic implications for a required increase in compliance monitoring for the small 

and medium surface water systems in the Midwest could be significant. For example, 

assume a surface water system serves 500 connections (approximately 1,500 people) in 

the Midwest and its customers have an average monthly water bill of $30. The total 

annual revenue for this system would then be $180,000. The analysis for a single 

compliance sample using the approved GC-MS analytical methods costs approximately 

$200. Assuming an additional $100 for sample collection and shipping yields a cost of 

$300 for each additional compliance monitoring sample. So increasing the compliance 

sampling from quarterly (four samples per year) to eight samples per year would increase 

the monitoring costs by $1,200, which is almost 1% of the total annual revenue for this 

example system. 

One potential option to mitigate the additional monitoring cost is to have the registrants 

and/or the users agree to pay for this additional compliance monitoring for a limited 

number of surface water systems in the Midwest. A regulatory framework would need to 

be developed so that this additional burden does not end up with the utilities, and 

ultimately, in their customers’ rates. 

If any revisions are needed to either the numerical standard or the compliance monitoring 

frequency, or if a total triazine standard needs to be developed, AWWA relies on EPA’s 

toxicological, epidemiological, and cost-benefit expertise to develop the appropriate risk 

management option for drinking water. AWWA recommends that EPA develop the 

appropriate drinking water risk management option as soon as possible as the atrazine 

issue has dragged on since the special review started in the ‘90s. The media continues to 

publish stories about weed-killer in drinking water, and utilities and their customers need 

a resolution to this issue once and for all. 
Docket EPA-HQ-OPP-2010-0125 

April 7, 2010 

Page 5 

In conclusion, AWWA recommends that: 

• EPA complete this new evaluation of atrazine as soon as possible and continue to 

hold to its principles of good science and transparency; 

• EPA use its toxicological, epidemiological, and cost-benefit expertise to develop 

the appropriate risk management option for drinking water as soon as possible; 

and 

• The registrants and/or the users should pay for any additional compliance 

monitoring (if needed) for water utilities. 

If you have any questions about these comments, please feel to call Alan Roberson or me 

in our Washington Office at 202-628-8303. 

Yours Sincerely, 

Thomas W. Curtis 

Deputy Executive Director 

cc: Peter Silva—OW 

Steve Owens—OPPTS 

Bob McNally—OPP 

Melanie Briscoe—OPP 

Cynthia Dougherty—OGWDW 

Pam Barr—OGWDW 

Ed Ohanian—OST 

Alan Roberson 

Steve Via 
Docket EPA-HQ-OPP-2010-0125 

April 7, 2010 

Page 6 

Peer-Reviewed Publications Resulting from Triazine Research 

• Graziano, N., McGuire, M., Adams, C., Roberson, A., and Blute, N. 

National Atrazine Occurrence Monitoring Program (2003) Using the 

Beacon ELISA Method. Journal AWWA, 98:10:111 (October, 2006). 

• Jiang, H., Adams, C., Graziano, N., Roberson, A., McGuire, M., and 

Khiari, D. Occurrence and Removal of Chloro-s-Triazines in Water 

Treatment Plants. Environmental Science & Technology

(40:11:3609). 

• Jiang, H., Adams, C., Graziano, N., Roberson, A., and McGuire, M. 

Enzyme Linked Immunoassay Analysis (ELISA) of Atrazine in Raw 

and Finished Water. Environmental Engineering Science (23:2:357). 

• Graziano, N., McGuire, M., Roberson, A., Adams, C., Jiang, H., and 

Blute, N. 2004 National Atrazine Occurrence Monitoring Program 

Using the Abraxis ELISA Method. Environmental Science & 

Technology (40:4:1163). 

• Adams, C., Jiang, H., McGuire, M., Graziano, M., Roberson, A and 

Frey, M. Accuracy and Interferences for Enzyme-Linked 

Immunoassay Tests for Atrazine. Journal AWWA, 96:12:126 

(December, 2004). 

• Jiang, H., Adams, C., and Koffskey, W. Determination of Chloro-sTriazines Including Didethylatrazine Using Solid-phase Extraction 

Coupled with Gas Chromotography-Mass Spectrometry. JournalChromotography-A, 1064:2:219.