Comments on BPTCP OP Pesticide Aquatic Life Toxicity Issues

G. Fred Lee & Associates
27298 E. El Macero Dr.
El Macero, California 95618-1005
Tel. (530) 753-9630 Fax (530) 753-9956
web site:
Please note the new area code for telephone and fax has been changed to 530

June 26, 1998

John Caffrey, Chairman
State Water Res Control Board
PO Box 100
Sacramento, CA 95812-0100

Dear Chairman Caffrey and Members of the Board:

Much of the June 18, 1998 workshop devoted to review of the Board's Final FED, "Water Quality Control Policy for Guidance on the Development of Regional Toxic Hot Spot Cleanup Plans," was devoted to organophosphate (OP) pesticide aquatic life toxicity issues. As discussed below, I am highly involved in OP pesticide aquatic life toxicity issues. I found that some of the comments made at the workshop were not in accord with what is known about OP pesticide toxicity to aquatic life and the approaches that need to be implemented to properly regulate OP pesticide aquatic life toxicity. I wish to provide the Board with some comments on the OP pesticide toxicity issues in connection with its review of the BPTCP Guidance Policy.

There was considerable discussion at the June 18th Board workshop about the terms "hazardous" and "bioaccumulation." As Dr. Chris Foe pointed out, OP pesticides are occurring in the State's waters at sufficient concentrations to kill aquatic life. The statement about these chemicals not accumulating in sediments is incorrect, at least with respect to chlorpyrifos. Chlorpyrifos does tend to sorb to sediments. The BPTCP program has found chlorpyrifos in Upper Newport Bay sediments. Whether it is toxic in the sorbed form remains to be determined. Work in the Bay Region by Katznelson indicates that there may be a sediment component associated with diazinon in urban creeks which increases the period of time that the toxic pulse associated with a stormwater runoff event lasts. There is no technical issue about the OP pesticides diazinon and chlorpyrifos aquatic life toxicity associated with urban and rural stormwater runoff accumulating in the water and possibly in the sediments to a sufficient extent in the vicinity of aquatic life to be toxic (hazardous) to some forms of aquatic life, and possibly to higher trophic level organisms through impacting their food supply.

As Board member Ms. Forster pointed out, the key issue is not to focus on the wording, but to get on with developing a meaningful control program where OP pesticides are significantly impairing the beneficial uses of the State's waters. There was some discussion at this workshop about the necessary steps to properly regulate OP pesticide-caused aquatic life toxicity. This is a topic that has been of concern to me for the past several years. On Monday, June 22, 1998 I presented a paper at the Northern California Society for Environmental Toxicology and Chemistry annual meeting that was held in Reno, Nevada devoted to regulating OP pesticide aquatic life toxicity. Based on the discussions at the BPTCP workshop, I felt that the Board may find that some of the materials that I have developed covering my thoughts on how to regulate the OP pesticide aquatic life toxicity, the general nature of the OP pesticide aquatic life toxicity problem in the State, and a summary of the work that we have been doing over the past three years in Orange County in cooperation with the Santa Ana Regional Water Quality Control Board on OP pesticide aquatic life toxicity issues may be of interest to the Board members. Enclosed is a set of comments that provides information in each of these areas. The attached comments are based on periodic work on pesticide water quality issues over the past 40 years. A summary of these activities is appended to this statement.

At the previous BPTCP workshop, there were some discussions about whether the State Board-DPR MAA, which is supposed to be developing a control program for OP pesticide toxicity, is "working." An aspect of this issue that has not been discussed but is now clear is that very small amounts of these pesticides in stormwater runoff or fugitive runoff associated with urban properties and agricultural use can cause widespread toxicity to certain forms of aquatic life. In Orange County, our estimates are that only about a pound or so of the 50,000 pounds per year of chlorpyrifos and diazinon that are used in the county and Upper Newport Bay watershed are responsible for the toxicity that has been found over the past two years in each of the stormwater runoff events that have been monitored. From my expertise and experience in this topic, it is clear that if it is found that the OP pesticide toxicity problem is a significant cause of water quality use impairment in a waterbody, then anything less than severely restricting the use of these pesticides will not likely control the problem.

As discussed in the enclosed materials, the key issue that should be immediately addressed is an assessment of what magnitude, duration of exposure, and areal extent of OP pesticide aquatic life toxicity constitutes a significant threat to the beneficial uses of a waterbody. The bottom-line issue that has to be resolved before it will be possible to start to meaningfully regulate OP pesticide toxicity is what is the meaning of having Ceriodaphnia or mysid-like toxicity where toxic pulses pass into a waterbody, like Upper Newport Bay, the Sacramento River, San Francisco Bay, the Delta, etc. The thrust of my recommended regulatory approach is that there is need for the State Board to appoint an independent expert panel who can work with the State and Regional Boards, DPR, pesticide manufacturers and formulators, environmental groups, and others in developing a consensus approach for determining the level of OP pesticide-caused aquatic life toxicity that represents a significant adverse impact to the beneficial uses of a particular waterbody.

From my experience in working on environmental impacts of pesticides over the past 40 years and work over the past several years on OP pesticide toxicity, there will be situations where the toxicity that is being found associated with agricultural and in some cases urban stormwater runoff will be judged to be of sufficient potential significance to cause the regulatory agencies to severely restrict the use of OP pesticides. However, there will also be situations where the continued use of OP pesticides, at least in urban environments, will not be found to be significantly adverse to the beneficial uses of the State's waters.

The expert panel that I recommend would have the responsibility of developing guidance on how to develop the site-specific information needed to determine whether OP pesticide toxicity associated with stormwater runoff from urban and rural sources is a significant threat to the beneficial uses of the State's waters. With respect to whether the MAA is working, I can unequivocally predict that the "education"-"voluntary" approach that DPR is using today will not prevent OP pesticide toxicity from occurring in the State's waters associated with stormwater runoff from urban and rural areas. It is my recommendation that the State Board immediately start to proceed to develop the information needed to regulate OP pesticide aquatic life toxicity by the Regional Boards and the State Board so that action can be promptly taken when it becomes recognized two years from now that DPR's current approach in the MAA has not prevented OP pesticide toxicity in the State's waters.

The enclosed write-up is designed to provide guidance to gathering some of the necessary information that Chris Foe discussed in his presentation to the Board at the workshop. If the Board members or others have questions or wish further information on any of the topics that I have covered in the attached materials, please contact me. Please contact me if I can be of assistance in helping the State formulate appropriate policy for regulating OP pesticide toxicity.

Please include these comments as part of the comments that I am submitting on the BPTCP Cleanup Plan guidance.

Sincerely yours,

G. Fred Lee, PhD, DEE

Copy to: W. Pettit
C. Wilson, Esq.
W. Attwater, Esq.


G. Fred Lee's Pesticide and Water Quality Impact Experience

My work on pesticides goes back to growing up on a farm near Delano in the Central Valley where, during high school, I drove a spray rig for pesticide application. My undergraduate and graduate college degree work included extensive coursework on medical entomology, particularly as it relates to the various types of pesticides for the control of pests, such as mosquitoes, that transmit malaria and other insect-borne diseases. In my 30-year university graduate-level environmental engineering - environmental science teaching and research career, I did extensive research on pesticide fate and effects.

Teaching at the University of Wisconsin, Madison, I was Secretary for the Technical Advisory Panel for the Wisconsin Pesticide Review Board. This panel made recommendations on pesticide regulations within the state. Further, in connection with the ASTM Committee E-35, I organized and chaired for several years the Pesticide Fate/Modeling Section of this committee. I have done extensive research on the chlorinated hydrocarbon pesticides, some of the heavy metal pesticides, such as lead and arsenic, and more recently, I am highly involved in the organophosphate (OP) pesticide issues. Four years ago, I initiated work in Orange County with the Santa Ana Regional Water Quality Control Board and the Orange County stormwater management agency in defining the water quality use impairments of Upper Newport Bay associated with urban and agricultural stormwater runoff to the Bay. At this time, I am providing technical leadership for a substantial research effort devoted to defining the current water quality significance of OP and other pesticide toxic pulses as they enter Upper Newport Bay associated with each stormwater runoff event. This work is designed to provide the Santa Ana Regional Water Quality Control Board with background information needed to ultimately develop a TMDL by 2002 for toxics entering Upper Newport Bay. This TMDL is an outgrowth of a consent decree that the US EPA signed with an environmental group that had filed a lawsuit against the Agency.. Since then I have followed closely the work of Dr. Val Connor on the Sacramento River watershed and Dr. Chris Foe in the San Joaquin River watershed and Delta on OP pesticide toxicity issues. I am serving as a technical advisor to the DeltaKeeper on a pesticide monitoring program for the Delta. Further, I have been active for the past year on the Urban Pesticide Committee organized by Dr. Tom Mumley of the San Francisco Regional Board and Dr. Val Connor of the Central Valley Regional Board.

Reference as: "Lee, G.F., 'Comments on BPTCP OP Pesticide Aquatic Life Toxicity Issues,' letter to J. Caffrey, State Water Resources Control Board, Sacramento, CA, June (1998)."

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