April 12, 2010

Ms. Allison Wiedeman
Rural Branch Chief
Office of Water US Environmental Protection Agency 1200 Pennsylvania Avenue, NW Washington, DC 20460

RE: Follow-up to February 24, 2010 Meeting Regarding National Pollutant Discharge Elimination System Permits for Pesticide Application To, On,
or Near Waters of the United States

Dear Ms. Wiedeman:

Thank you for the opportunity to meet with you and your staff to discuss EPA’s current effort to develop a regu latory structure under the Clean Water Act (CWA) National Pollutant Disc harge Elimination System Permit (NPDES) program for permitting pesticide application in, above, or adjacent to surface water. The utility memb ers of the American Water Works Association, Association of California Water Agencies, and the Association of Metropolitan Water Agencies appreciate you and your staff’s recognition as to how critical aquatic pesticides are to maintaining effect ive water facility operations throughout the nation. As we discussed at the meeting, aquatic pesticides serve numerous crucial roles for our members.

Aquatic pesticides are essential to assu ring safe and aesthetically acceptable drinking water, enabling irrigation systems to effectively convey and deliver water to crops, and preventing the prol iferation of aquatic plant and animal pest species. And while we all need to recognize that pesticides are one of the many tools we have available to contro l pests (plant and animal) and that we should always strive to use the tool th at achieves pest management objectives with the least impact on the environment, we also need to recognize that aquatic pesticides are often the most efficient and cost-effective approach. Furthermore, when considering the bigger picture, there are many circumstances in which the proper use of pesticides can actually reduce the overall impacts to the environment while enhancing public health.

While we support including water resource management pesticide applications within the general federal NPDES permit model, we believe theMs. Allison Wiedeman April 12, 2010 Page 2

unique aspect of such applications need s to be recognized. After all, our members’ aquatic pesticide applications ar e specifically designed to be either directly applied to waterbodies or to infrastructure facilities that convey and or store water. Specific examples of aquatic pesticide uses by our members include control of disease carrying organi sms, algae, floating, submersed, and emergent aquatic plants, mollusks an d other invertebrates, and invasive plant and animal species. Such uses ar e fully considered by EPA’s Office of Pesticide Programs when determining whether a specific pesticide should be approved for such uses and if so, what additional restrictions should be imposed on such uses. It is essent ial that the general NPDES permit for pesticide use acknowledge that co mpliance with Federal Insecticide Fungicide and Rodenticide Act (FIFRA) label provisions will, in the vast majority of cases, satisfy the requirem ents of the permit. As you are aware, each FIFRA label is supported by an ex tensive body of research and expert assessment compiled by EPA. FIFRA labe ls, in general, effectively balance efficacious pesticide application with minimizing adverse impacts associated with pesticide residuals.

We also believe that the new permit should recognize and support state and local efforts to regulate pesticide use to ensure environmental protection and human health and safety. With regards to this last point, as we discussed, it is critical that the general permit be crafted in a manner that accounts for the magnitude of variation across the country, in terms of geographic and demographic conditions and pest management challenges, and consequently, provides sufficient flexibility to allow for local solutions to address local

circumstances.

You and your staff posed several specific questions. Attachment A to this letter summarizes each question and in cludes an associated response. We appreciate the agency’s consideration of our concerns and recommendations. If there are any questions, please dire ct them to Steve Via, AWWA, at (202) 326-6130, Mark Rentz, ACW A, (916) 441-4545, and Erica Brown, AMWA, (202) 331-2820.

Best regards,

Thomas W. Curtis Mark S. Rentz Diane VanDe Hei Deputy Executive Director Director Executive Director AWWA Government Affairs ACWA Regulatory Affairs AMWAMs. Allison Wiedeman April 12, 2010 Page 3

cc: Jack Faulk, EPA/OW/OWM Bill Jordan, EPA/OPPTS/OPP Mike Muse, EPA/OW/OGWDW Mike Finn, EPA/OW/OGWDWAttachment A

Question 1. What is the best way to express the application (e.g., area, volume, linear distance, etc) for our members’ applications?

Water volume in acre-feet is the most common metric though it may be simpler to administer a permit progra m where key thresholds are expressed
in surface area or linear distance. Wa ter volume is the metric to which one most often returns when planning an aqu atic pesticide application. You will
find that this measure can be derive d from a few simple measurements (e.g., the length, width, and average depth 1 of the application area). There are instances, when application of herbicid e occurs on the shoreline of a water body (e.g., a canal, ditch, pond, et c.) in these instances a simple linear measure could be used, recognizing that the nature of the permit presumes a volume of the adjacent waterbody is receiving the pesticide as well.

By reflecting application in water volume treated, e.g., acre-feet, the user is able to represent either the static volu me of a lake, pond or reservoir or flowing water volume in a canal or ditch. Water bodies can differ tremendously in size. For example, a canal for transferring water can be one mile or hundreds of miles long. Similarl y, a canal might be 100 feet or just a few feet wide. Consequently, if a linea r distance is used to simplify permit language and simplify implementation, it would be important to include flexibility to address situations wher e the assumed linkage between linear
distance and affected volume is not sound.

A final aspect of clearly communicating linear measurements in the context of this NPDES permit is that applicatio n is typically occurring on both banks of a linear waterbody (e.g., canal, ditch, etc.). So, for every mile of actual distance, the applied distance is 2 miles. Current practice is to discuss linear distance in terms of the length of ban k to which pesticide is applied. EPA should be very clear when it is expre ssing the length of a water feature (e.g., a canal, stream, etc.) vs. when it is describing the length of bank to which pesticides are applied.

1 When the FIFRA label includes a ta rget concentration, the effective volume can and should be limited to the volume where that target concentration exists, for instance, in the case of surf ace application of copper sulfate the often used depth is three feet.Question 2. What is an appropriate threshold for Notices of Intent?

There are at least three significant na tionwide assessments of the number of
lakes in the United States. The fi rst conducted Olsen et al. (2009) 2 based on

1999 data indicates that there are al most 270,800 lakes di scernable from United States Geologic Survey (USGS) USGS Reach 3 data. A subsequent effort also published in December 2009, the National Lakes Assessment (NLA), was limited to lakes greater than 10 acres in size; it placed the national inventory of lakes at 49,546. Roughly 41% of the lakes reflected in the NLA are categorized as man-made. A third compilation was prepared in 2009. This final compilation was prep ared by the U.S. Army Corps of Engineers, the National Inventory of Da ms (NID). NID indicates that there are almost 84,000 dams in the United States, implying that there are a similar number of constructed impoundment s. We were not able to identify a similar national compilation of the miles of irrigation canals and ditches. The Army Corps of Engineers data is limited to man-made impoundments, but it is the only dataset that provid es insight into who is managing these water resources nationally. Based on NID more than 18,000 lakes and reservoirs are managed by local governme nt and utilities. NID also indicates that almost 15,000 lakes and reservoirs are managed for either drinking water or irrigation supplies.

Our members’ experience indicates that the use of integrated pest management (IPM) is prevalent and that IPM includes the use of pesticides as needed. Accordingly, virtually every water system that relies on surface water supplies may at some time need to apply pesticides. Moreover the distribution of invasive species such as zebra mussels ( http://www.invasivespeciesinfo.g ov/aquatics/zebramussel.shtml ) and quagga mussels ( http://www.invasivespeciesinf o.gov/aquatics/quagga.shtml ) continues to grow; wherever infestatio ns of these species occur there is substantial likelihood that drinking wa ter suppliers and irrigation districts will need to utilize pesticides to protect the functionality of their
infrastructure.

Because aquatic pesticide application in reservoirs is typically targeted at a portion of the water body, and for most applications effective concentrations are limited to only a portion of the wate r column, it seems appropriate to take these factors into account when setting the NOI for reservoir treatment. Based on the data in Reach 3, NLA, NID and our members’ experience, a
reasonable NOI is 300 surface acres. This surface area is consistent with

2 Anthony R. Olsen, Blaine D. Snyder, Leanne L. St ahl, Jennifer L. Pitt. E nviron Monit Assess (2009) 150:91–100. Survey design for lakes and reservoirs in the United States to assess contaminants in fish

tissue.typical assumptions used to treat surfac e water bodies with algaecides, which is a pesticide treatment common among many of our members.

Irrigation systems vary tremendously in scope and scale both within any given irrigation activity and between irrigation regions. For example in California there is an extensive irrigation canal system where individual
canals can measure 100 or more feet in width; as the volume of water gets closer to its point of application, the size of the conveyance systems reduces significantly. Table 1 provides an illustrative example.

Table 1: Example Canal/Ditch Length of 50 miles (Resulting treated bank length of 100 miles)

Average

Width (feet) Surface (acres) Assumed Depth (feet) Static Volume (acre feet)

5 30.3 1 30.3

10 60.6 3 363.6

50 303.0 10 3030.3

100 606.1 10 6060.6

If 300 acres represents a reasonable NOI for reservoir / lake applications of aquatic pesticides, then a comparable surf ace area could be used as a point of departure for calculating the NOI for irrigation systems. These systems could either calculate a surface area or volume of their water treated. By way of comparison if the average width and depth of the irrigation system
were 10 feet and 3 feet re spectively, then roughly 250 linear miles of canal
would be the NOI.

Question 3. What is the specific process fo r dealing with endangered species / critical habitat in California Aquatic Pesticide General Permit process?

Endangered species are addressed both in California and in other states through direct interaction between the relevant state agencies and the permittee. This approach allows th e responsible entity to incorporate measures to avoid harm to endangered species in their overall IPM process.

Question 4. Are there data to illustrate that post-application pesticide
residual levels are minimal?



### The FIFRA pesticide label typically incl udes appropriate pesticide application rates for the target pest species and application. The label often includes information on persistence of the pest icide in the environment. Every pesticide (i.e., herbicide, algaecide, surf actant, etc) has a different environmental persistence. For some pesticides this means that there will be no detectable

### residue, but for others a residue will exist for some time period. For those chemicals that have residue, the amo unt of residue will depend upon the application rate, time after application th e chemical is tested, and other factors.

A recently compiled dataset organized by Blankenship and Associates based on compliance with the California NPDES a quatic pesticide permit does provide some insight into the presence of pesticid e residuals. This dataset represents data from 30 water systems and irriga tion districts in central and northern California over a seven year period. The pesticides listed (glyphosate, nonylphenol, acrolein, and copper) are t hose applied by some or all of the contributing owner/operators. See Attachment B.

Question 5. Is pesticide use declining over time? Is this drop linked to integrated pest management?

A nearby case study of pesticide use de cline over time is the use of copper algaecides to control algae blooms in the Occoquan Reservoir. The Occoquan Reservoir is located in northern Virginia and is managed by Fairfax Water. Over the past three decades, source water protection measures have been implemented to help mitigate the i mpacts of the increasing suburban development in the Occoquan watershe d. These measures have included indirect potable reuse through advanced wastewater treatment and stringent phosphorus reduction requirements for storm water runoff. While not directly attributable to the pesticide use reduction, these measures have stabilized water quality in the Occoquan Reservoir. Further, Fairfax Water undertook several pro-active operational actions including:

1. Evaluating the reservoir and its ecology to determine the key regions of the reservoir to which algaecide application should be used to be effective and develop the ability to recognize the onset of an algal bloom that will i mpair drinking water treatment,

2. Installing continuous monitoring equipment within the reservoir to provide a more comprehensi ve view of water quality.

3. Employing standard operating procedures that utilize ongoing monitoring to facilitate targeted and timely pesticide application.

4. Making changes in the depth at which water is withdrawn from the reservoir to reduce the concentration of algae entering the water treatment plant.

5. Maintaining and upgrading as needed an in-reservoir aeration
system.6. Considering algae-related water quality issues in making improvements to drinking water treatment. The current plant disinfects using ozone which is a very effective oxidant and removes many algae-related taste and odor compounds.

Because observed algae occurrence varies with flow conditions, growing season temperatures, and other factors, it is not possible to identify a single action that led to reduction in algaecid e use. Despite an extensive suite of actions, algae blooms continue to occur at levels that sometimes necessitate use of targeted copper algaecide treatme nts. The timing and intensity of these blooms are highly variable.

This case study is a good example of IPM reducing the amount of applied pesticide. By clearly identifying whic h algal species represent a challenge to treatment, and conditions when algal le vels are such that other tools are inadequate to protect the drinking water supply, Fairfax Water has developed a suite of strategies that together address th e system’s water

treatment needs and minimize both th e area and magnitude of pesticide application in the reservoir. Ho wever, it should be noted that implementation of IPM does not necessarily mean a concurrent reduction in pesticide use.

Question 6. What are the key elements of defining the “entity in responsible charge”?

As is typical practice in permitting und er the Clean Water Act, the “entity in responsible charge” is charged with co mplying with regulatory requirements. In the case of the proposed NPDES ge neral permit for pesticides, complying

entails:

1. Determining if an NOI must be submitted and if so making such submission,

2. Assuring that provisions of the general permit are met including recordkeeping and reporting requirements, and

3. Adherence to IPM-based strategy with respect to pesticide application.

In almost all cases the “entity in responsible charge” will be the owner/operator of the waterbody being trea ted. This entity is very typically the one that understands site history and has firsthand knowledge of site characteristics. Accordingly, the familia rity that this entity has allows for the best and most appropriate decision on the use of pesticides. In the case of a community water system or irrigation di strict, it would be the utility itself. The utility could then either conduct the application itself or contract forapplication services as necessary, ensuring that appropriate contractual requirements are in place to assure comp liance with the NPDES permit. It is possible that either because ownershi p of the water resource rests with another entity or due to the structure of the utility that the responsibilities associated with the NPDES would be delegated through a contractual arrangement. In order to have flexibilit y to deal with this limited subset of cases, the NPDES permit structure should be based on “entity in responsible charge.”

Question 7. Nationally where are th ere irrigation districts?

Irrigation districts are organized in numerous states to ensure a reliable water supply to agriculture, includin g the states of: Arizona, California, Colorado, Idaho, Kansa, Montana, North Dakota, Nebraska, New Mexico, Nevada, Oregon, South Dakota, Texas, Washington, and Wyoming. These states are all reflected in a compilati on prepared by the U.S. Bureau of Reclamation (http://www.usbr.go v/rra/IDStatus/IDStatus.pdf ). Many U.S. Bureau of Reclamation projects include an irrigation component (an alternative project specific website link is http://www.usbr.gov/projects/index.jsp.

The National Water Resources Association may be better positioned to provide a complete national picture of wh ere irrigation districts are organized
and estimate the number of miles of asso ciated irrigation canals and ditches.
NWRA maintains a list of its members at http://www.nwra.org/member_links.php . There are also state level associations for irrigation districts like the Washington State Water Resources Association, http://www.wswra.org

.Attachment BRevised: 3/23/2010Source: Blankinship & AssociatesSummary of Post-Application Detection of PesticidesApplied to Water to Control Aquatic Vegetation inCalifornia: 2002-2009877811285386972249700006001002003004005006007008009001000Glyphosate Nonylphenol Acrolein Copper

# of SamplesTotal # of Samples Analyzed# of Detects > Water Quality Objective (WQO) inDownstream Sample Immediately After Application# of Detects > WQO in Downstream Sample 4-7 Days AfterApplication