Evaluation of Pesticides in Ground Water - ACS Publications

28 Ground Water Regulations Impact, Public Acceptance, and Enforcement 1

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Orlo R. Ehart , Gordon Chesters , and Kari J. Sherman

Downloaded by CORNELL UNIV on September 9, 2016 | http://pubs.acs.org Publication Date: July 17, 1986 | doi: 10.1021/bk-1986-0315.ch028

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Trade and Consumer Protection, Wisconsin Department of Agriculture, Madison, WI 53708 Water Resources Center, University of Wisconsin-Madison, Madison, WI 53706

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Sanctioning pesticides for agricultural use was based on equating environmental and public health risks to crop production benefits. More recently, the introduction of groundwater protection into pesticide regulations has modified the equation by adding other elements of protection. During the past decade pesticide issues have been emotionally charged with the extremists' views most notably reported. The public believes that groundwater deserves greater protection than surface water because improving the quality of contaminated groundwater is more difficult and costly. This coupled with the users'--particularly rural residents--concerns that their drinking water is being polluted, has lead to acceptance of groundwater regulations by pesticide users often opposed to regulation. Enforcement of regulations, based on acceptable tolerance levels of pesticides in groundwater, must rely on quality-assured data. Regulatory mechanisms include changes in use practices, moratoria and cancellation of registrations. Mathematical models-used as an information source--could be helpful in evaluating the consequences of pesticide use. Enforcement sanctions follow traditional civil and criminal remedies but innovative cost incentives might be needed to accelerate protection programs. Mechanisms of implementation of land management controls vary from state to state. The F e d e r a l I n s e c t i c i d e , F u n g i c i d e and R o d e n t i c i d e A c t , as amended, establishes a policy f o r determining the acceptability of a p e s t i c i d e use, o r the c o n t i n u a t i o n o f that use, according t o a r i s k / b e n e f i t assessment. This p o l i c y , administered by t h e U.S. E n v i r o n m e n t a l P r o t e c t i o n Agency (EPA), r e c o g n i z e s t h a t p e s t i c i d e s are i n t e n t i o n a l l y p l a c e d i n t h e environment f o r purposes o f p e s t control. Contrary t o some p u b l i c o p i n i o n , the r i s k / b e n e f i t assessment does not determine t h a t t h e use i s t o t a l l y " s a f e " n o r 0097-6156/86/0315-0488$06.00/0 © 1986 American Chemical Society

Garner et al.; Evaluation of Pesticides in Ground Water ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

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Ground Water Regulations


suggest t h a t a l l uses of a p e s t i c i d e w i l l not a d v e r s e l y a f f e c t the environment, including effects on human h e a l t h . As long as benefits outweigh a d v e r s e e f f e c t s uses of a pesticide can be r e g i s t e r e d , i . e . , o f f i c i a l l y s a n c t i o n e d by the EPA. Despite this permissiveness in the law, i t has become i n c r e a s i n g l y d i f f i c u l t to j u s t i f y the use, or c o n t i n u e d use, of many p e s t i c i d e s . The a b i l i t y to r e c o g n i z e p o t e n t i a l r i s k s has improved w i t h advances i n t e c h n o l o g y . The ability to detect increasingly lower concentrations of pesticides, increased knowledge of and c o n c e r n about p o t e n t i a l c h r o n i c e f f e c t s , and the f i n d i n g of low l e v e l s of p e s t i c i d e s i n d r i n k i n g water i n s e v e r a l a r e a s of the U n i t e d S t a t e s have added more f a c t o r s to the r i s k s i d e o f the r i s k / b e n e f i t l e d g e r w h i l e the b e n e f i t s i d e has remained relatively static. Public

P e r c e p t i o n s toward Groundwater P o l i c y and

Regulation

A study conducted f o r the N a t i o n a l Academy of S c i e n c e s (1) has revealed that the average C a l i f o r n i a n i s becoming increasingly aware of and concerned about t o x i c c h e m i c a l s as a t h r e a t to groundwater. This important perception i s without regard to the c o n t a m i n a n t ' s s o u r c e , r e l a t i v e t o x i c i t y or p e r v a s i v e n e s s . The p u b l i c g e n e r a l l y does not u n d e r s t a n d nor a c c e p t the consequences o f f e d e r a l p o l i c y , which a l l o w s the p u r p o s e f u l , j u d i c i o u s i n t r o d u c t i o n of p e s t i c i d e s i n t o the environment, even i f they may have a m i n i m a l y e t measurable u n d e s i r e d e f f e c t . Thus, i f o n l y minute q u a n t i t i e s of a pesticide reach groundwater, the federal policy of a r i s k / b e n e f i t assessment i s r e j e c t e d by much of the p u b l i c r e g a r d l e s s of any assessment o f the b e n e f i t o f the p e s t i c i d e i n i m p r o v i n g c r o p p r o d u c t i o n and q u a l i t y . When e a s i l y a c c e s s i b l e f a c t s on t e c h n i c a l i s s u e s are u n a v a i l a b l e , the p u b l i c f r e q u e n t l y f a v o r s s i m p l e p o l i c i e s . In the case o f groundwater, t h i s i s the p o l i c y of n o n d e g r a d a t i o n which a l l o w s f o r no change i n water q u a l i t y . The e s t a b l i s h m e n t o f n u m e r i c a l g r o u n d water s t a n d a r d s i s an i m p o r t a n t p o l i c y a l t e r n a t i v e f o r assessing the s i g n i f i c a n c e of manmade or n a t u r a l l y o c c u r r i n g contamination. The f e d e r a l government must e s t a b l i s h those l e v e l s i f the p u b l i c i s ever to p e r c e i v e the d i f f e r e n c e between the mere p r e s e n c e of a p e s t i c i d e i n groundwater and an a c u t e or c h r o n i c h e a l t h significance a s s o c i a t e d w i t h exposure to some l e v e l of c o n t a m i n a t i o n . The impacted community must a c c e p t r e g u l a t i o n and cooperate w i t h the r e g u l a t o r y a u t h o r i t y i f a management approach to s o l v i n g the problem of contaminants i n groundwater i s to s u c c e e d . Regulat i o n r e q u i r e s a c c e s s to t e c h n o l o g i c a l i n f o r m a t i o n , the c o o p e r a t i o n and d e d i c a t i o n of r e s e a r c h e r s and adequate s u r v e i l l a n c e to a s s u r e v i o l a t o r s are d e t e r r e d . R e g u l a t i o n s have c o s t s a s s o c i a t e d with them, but they encourage use of those p e s t i c i d e s which create minimum r i s k s . However, new r e g u l a t i o n s may s u b s t a n t i a l l y modify the p r e s e n t uses of p e s t i c i d e s . P e s t i c i d e s can a d v e r s e l y a f f e c t humans or the environment i f not h a n d l e d p r o p e r l y . Because o f t h e s e d e t r i m e n t a l consequences, a l e r t s u r v e i l l a n c e and speedy and just enforcement become e s s e n t i a l components of the regulatory program. O u t r i g h t bans can r e s u l t but they a r e the p r o d u c t of a d e c i s i o n - m a k i n g p r o c e s s r a t h e r than the f i r s t l i n e of d e f e n s e .



490

E V A L U A T I O N O F PESTICIDES IN G R O U N D WATER

Most Americans a r e c o n c e r n e d about the q u a l i t y of groundwater and b e l i e v e t h a t i t i s more d i f f i c u l t and c o s t l y t o p r o t e c t and r e n o v a t e t h a n s u r f a c e water. When t h e i r c o n c e r n s a r e c o u p l e d w i t h i n a d e q u a t e i n f o r m a t i o n and an u n w i l l i n g n e s s to a c c e p t r e g u l a t o r y s t a n d a r d s , i t becomes d i f f i c u l t i f not i m p o s s i b l e to e s t a b l i s h balanced p u b l i c p o l i c y . Groundwater i s one of the l e a s t t a n g i b l e components of the t o t a l environment. I t i s the d e c i s i o n to use g r o u n d w a t e r — a s a d r i n k i n g water s o u r c e f o r humans and domestic a n i m a l s , f o r i r r i g a t i o n and f o r i n d u s t r i a l u s e s — t h a t has made i t s c o n t a m i n a t i o n a r e a l and immediate problem. S i n c e groundwater i s not v i s i b l e and i t s p r o p e r t i e s and f l o w p a t t e r n s a r e p o o r l y u n d e r s t o o d by laymen, the p u b l i c i s u n w i l l i n g t o s u p p o r t a p o l i c y p e r m i t t i n g the use of a p e s t i c i d e t h a t c o u l d be found i n groundwater, even i f the l e v e l s have no s i g n i f i c a n t e f f e c t on human h e a l t h and the environment. S i n c e water has d i f f e r e n t uses and q u a l i t i e s , v a r i a b l e s t a n d a r d s m a t c h i n g s a f e g u a r d s needed f o r p a r t i c u l a r uses now and i n the f u t u r e would be a p p r o p r i a t e . However, t h i s type o f s t a n d a r d s e t t i n g would be complex and i t may be d i f f i c u l t t o c o n v i n c e the p u b l i c o f the need f o r t h i s p o l i c y . N o n e t h e l e s s , such a system would provide greater flexibility i n devising b e s t management p r a c t i c e s to p r o t e c t the groundwater r e s o u r c e . Survey d a t a . The f o l l o w i n g s u r v e y s t a t i s t i c s (2) p r o v i d e some knowledge o f the p u b l i c ' s p e r c e p t i o n o f groundwater c o n t a m i n a t i o n . ο ο ο

ο

75% of the U.S. p o p u l a t i o n (75% i n W i s c o n s i n ) i s more w o r r i e d about p o l l u t i o n now t h a n 5 y e a r s ago. 48% o f Americans (58% i n W i s c o n s i n ) c o n s i d e r underground water p o l l u t i o n t o be a major problem, 91% (91% i n W i s c o n s i n ) endorsed n a t i o n a l s t a n d a r d s f o r s a f e d r i n k i n g water but o n l y 23% (20% i n W i s c o n s i n ) a r e w i l l i n g t o accept " s m a l l amounts o f c h e m i c a l s " i n water even i f such c o n t a m i n a t i o n meets government s t a n d a r d s , 63% of t h o s e asked (69% i n W i s c o n s i n ) d i s a g r e e d w i t h the i d e a t h a t i f the government a l l o w s " s m a l l amounts o f c h e m i c a l s i n w a t e r , " the water i s s a f e t o d r i n k .

When the p u b l i c was q u e s t i o n e d water pollution—particularly o p i n i o n s were o b t a i n e d . ο ο

ο

on a g r i c u l t u r a l s o u r c e s o f g r o u n d from pesticides—the following

Asked i f f a r m e r s use too many p e s t i c i d e s , n a t i o n a l l y 59% o f those s u r v e y e d (57% i n W i s c o n s i n ) answered y e s . 23% of a l l Americans s u r v e y e d (29% i n W i s c o n s i n ) b e l i e v e t h a t f e r t i l i z e r s and p e s t i c i d e s used on farms a r e a major n a t i o n a l problem causing water pollution; 76% (82% i n Wisconsin) c o n s i d e r them t o be a t l e a s t a minor problem. 35% (24% i n W i s c o n s i n ) b e l i e v e f e r t i l i z e r s and p e s t i c i d e s a r e not a problem i n t h e i r l o c a l d r i n k i n g water w h i l e o n l y 6% ( 3 % in Wisconsin) believe they a r e not a national problem. A l t h o u g h some r e s p o n d e n t s thought t h a t t h e i r l o c a l drinking water s o u r c e was s a f e , t h e y p e r c e i v e d t h a t a problem e x i s t s i n some o t h e r p a r t s o f the c o u n t r y .



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EHART ET AL.


491

A survey (3_) showed t h a t 56% o f r e s p o n d e n t s i n d i c a t e d a need to p r o t e c t farmers when a s k e d : "Do you t h i n k t h a t t h e s o l u t i o n s f o r water p o l l u t i o n i n W i s c o n s i n s h o u l d be planned so t h a t they do not i n c r e a s e c o s t s f o r f a r m e r s , o r a r e these problems so s e r i o u s t h a t we have t o have s o l u t i o n s even i f they mean h i g h e r c o s t s f o r farmers?" Of those surveyed, 50% i n d i c a t e d that solutions ( r e m e d i a l measures) f o r water p o l l u t i o n s h o u l d be planned n o t t o i n t e r f e r e w i t h t h e a b i l i t y t o c r e a t e new j o b s ; 6 1 % f a v o r s t a t e f i n a n c i a l a s s i s t a n c e t o farmers t o c o n t r o l p o l l u t i o n from a g r i c u l tural activities. I n a n a t i o n a l H a r r i s p o l l ( 4 _ ) , 63% i n d i c a t e d t h a t c l e a n water was o b t a i n a b l e w i t h o u t a f f e c t i n g j o b s ; however, i f i t were an e i t h e r / o r p r o p o s i t i o n , t h e p o p u l a t i o n surveyed b e l i e v e d t h a t h e a l t h i s more important than j o b s . These s u r v e y s and p o l l s p r o v i d e a snapshot o f p u b l i c o p i n i o n but do not n e c e s s a r i l y r e f l e c t the t r u e b e l i e f s o f s o c i e t y . However, they do i n d i c a t e t h e p a r a d o x i c a l elements i n d e a l i n g w i t h t h e p u b l i c ' s p e r c e p t i o n o f complex policy issues. A statistical survey study (5_) conducted f o r t h e EPA by C o r n e l l U n i v e r s i t y r e s e a r c h e r s r e p o r t e d t h a t 63% o f r u r a l homes have contaminated drinking water; nearly 30% have excessive bacterial counts but few have d e t e c t a b l e pesticide residues. Samples from w e l l s a t 2 6 7 s i t e s were s e l e c t e d f o r a n a l y s i s . The analyses were l i m i t e d to only those s i x p e s t i c i d e s f o r which maximum contaminant levels (MCLs) a r e n a t i o n a l l y e s t a b l i s h e d . R e s u l t s o f t h e study showed: ο

ο

Four out o f 1 2 1 s i t e s i n 1 6 s o u t h e r n s t a t e s c o n t a i n e d residues. The h i g h e s t l e v e l was 0 . 0 8 p a r t s p e r b i l l i o n yg/l). The MCL f o r l i n d a n e i s 4 ppb. Three out o f 3 2 s i t e s i n t h e west c o n t a i n e d m e t h o x y c h l o r maximum l e v e l o f 0 . 0 9 ppb. The MCL f o r m e t h o x y c h l o r i s

lindane (ppb o r with a 1 0 0 ppb

(6).

The executive summary (7_) o f t h e study states: "Endrin, l i n d a n e , m e t h o x y c h l o r , toxaphene, 2 , 4 - D and 2 , 4 , 5 - T P were v i r t u a l l y n e v e r d e t e c t e d among r u r a l h o u s e h o l d water s u p p l i e s . " The study draws no c o n c l u s i o n s on t h e e x t e n t o f c o n t a m i n a t i o n o f r u r a l water s u p p l i e s by p e s t i c i d e s beyond t h i s l i m i t e d s a m p l i n g . However, t h i s s m a l l d a t a base was t r a n s l a t e d and e x t r a p o l a t e d t o p r o v i d e a p u b l i c i n f o r m a t i o n a r t i c l e ( 8 ) which s t a t e s t h a t " l i n d a n e i s p r e s e n t i n 347,000 r u r a l h o u s e h o l d water s u p p l i e s " and "water i n more t h a n 200,000 r u r a l homes c o n t a i n s d e t e c t a b l e amounts o f m e t h o x y c h l o r . " T h i s type o f p r o j e c t i o n m i s l e a d s and i n f l a m e s t h e emotions o f t h e public regarding the e x t e n t and s e r i o u s n e s s of contamination. Editors should respond very forcefully to scare t a c t i c s and d e c i s i o n - m a k e r s must determine t h e r e l i a b i l i t y o f such s t a t e m e n t s . Some states have conducted surveys o f water quality. C u r r e n t l y t h e i n f o r m a t i o n a v a i l a b l e on t h e s t a t u s o f t h e q u a l i t y o f the n a t i o n a l groundwater r e s o u r c e i s i n a d e q u a t e t o draw any c o n c l u sions. G e n e r a l l y , assessments o f water q u a l i t y a r e a v a i l a b l e o n l y for l o c a l i z e d areas. The EPA has proposed a n a t i o n a l groundwater survey f o r 1 9 8 6 - 8 8 . The p r e l i m i n a r y d r a f t c a l l s f o r sampling 1 5 0 0 2000 wells f o r approximately 90 p e s t i c i d e analytes (9). Even though t h i s i n f o r m a t i o n w i l l be v a l u a b l e , a sample s i z e o f 3 0 - 5 0


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E V A L U A T I O N O F P E S T I C I D E S IN G R O U N D

w e l l s per s t a t e i s s t i l l i n a d e q u a t e to a s s e s s the q u a l i t y of n a t i o n ' s groundwater f o r c o n t a m i n a t i o n by p e s t i c i d e s .


Need f o r S c i e n t i f i c E v a l u a t i o n .

Z a k i e t a l . (10)

concluded

WATER

the

that:

"Our s o c i e t y seems to be w i l l i n g to a c c e p t t a n g i b l e and measurable r i s k s i n our d a i l y a c t i v i t i e s as a r e s u l t of c i g a r e t t e smoking, e x c e s s i v e f o o d and a l c o h o l i n t a k e , and the use of the a u t o m o b i l e . The same s o c i e t y , however, i s u n a b l e to t o l e r a t e p o t e n t i a l , i n t a n g i b l e and unmeasurable r i s k s from food additives, pesticides, air pollutants, and water contaminants. As p u b l i c h e a l t h a d m i n i s t r a t o r s , we have a responsibility not only to m o n i t o r and c o n t r o l these s u b s t a n c e s but a l s o to h e l p the p u b l i c become f u l l y aware of t h e i r r i s k s and b e n e f i t s w i t h o u t r e s o r t to r h e t o r i c on e i t h e r s i d e of the i s s u e . " I t i s d i f f i c u l t t o p r e v e n t some p e r s o n a l b i a s e s from e n t e r i n g professional attitudes. However, p r o f e s s i o n a l s s e r v i n g the p u b l i c i n t e r e s t must r e n d e r an u n b i a s e d p r e s e n t a t i o n of the f a c t s i f the r o l e of p u b l i c o p i n i o n i n the d e c i s i o n - m a k i n g p r o c e s s i s to be valid. P r o f e s s i o n a l s must adopt an u n b i a s e d a t t i t u d e , even i n those c i r c u m s t a n c e s where they have p e r s o n a l b e l i e f s which may d i f f e r from the f a c t s . H o l d e n (1_), i n commenting on an, as y e t , u n p u b l i s h e d r e p o r t t o the N a t i o n a l Academy of S c i e n c e s , s t a t e d t h a t t h e r e i s a l s o c o n s i d e r a b l e c o n c e r n t h a t p u b l i c a p p r e h e n s i o n about groundwater contami n a t i o n w i l l grow to the p o i n t where s t a t e w i d e or n a t i o n a l bans w i l l become p o l i t i c a l l y e x p e d i e n t , even i n c a s e s where p e s t i c i d e c o n t a m i n a t i o n i s a c o n t r o l l a b l e l o c a l i z e d phenomenon. The r o l e o f s c i e n t i s t s i n a s s u r i n g the use of r e l i a b l e d a t a i n the d e c i s i o n making p r o c e s s has become an i n t e g r a l p a r t of t h e i r p r o f e s s i o n a l activities. I t i s imperative that unbiased, accurate information be p r e s e n t e d by t r a i n e d p r o f e s s i o n a l s to s e c u r e p u b l i c a c c e p t a n c e of sound, r e a s o n a b l e p u b l i c p o l i c y r e g u l a t i n g the presence of p e s t i c i d e s i n groundwater. The p u b l i c i s not well informed on technical issues and frequently provides a r e a c t i o n r a t h e r t h a n an i n f o r m e d opinion. A l t h o u g h most p e o p l e can d i s t i n g u i s h v o l u n t a r y from involuntary r i s k , O r l o f f (11) p o i n t s out p e o p l e do not f o c u s on a p a r t i c u l a r s e t of r i s k s simply to s a f e g u a r d h e a l t h and s a f e t y ; the choice often r e f l e c t s a moral view. The government o p e r a t e s on the premise t h a t p u b l i c p o l i c y s h o u l d p r o t e c t a g a i n s t major r i s k s ; the p u b l i c s h o u l d a c c e p t minor r i s k s . By v i e w i n g an i s s u e from the moral perspective i t i s u n l i k e l y t h a t p u b l i c consensus can be reached. I t has not been shown t h a t v o c a l p a r t i c i p a n t s r e p r e s e n t the spectrum of p u b l i c o p i n i o n . U n l e s s the e f f e c t i v e n e s s of p u b l i c participation is enhanced, the advisability of direct public involvement in administrative decisions is debatable (12). A g e n c i e s a d m i n i s t e r i n g s t a t e p o l i c y must r e n d e r u n b i a s e d d e c i s i o n s based on the information a v a i l a b l e , use i t s best judgement to o b t a i n b a l a n c e d p o l i c y , and be a c c o u n t a b l e f o r t h e i r d e c i s i o n s .


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Development and A d m i n i s t r a t i o n

o f the A l d i c a r b

493

Rule i n W i s c o n s i n

W i s c o n s i n has had a number o f e x p e r i e n c e s i n d e a l i n g w i t h t r a c e s o f p e s t i c i d e r e s i d u e s i n groundwater; t h e most n o t a b l e i s t h e p r e sence o f a l d i c a r b r e s i d u e s i n s h a l l o w a q u i f e r s i n t h e C e n t r a l Sands region o f the State (Table I ) .

Table I .


Date July 1981 Nov. 1981 Jan. 1982 Mar. Mar. Aug. Apr. May

1982 1982 1982 1983 1984

Nov.

1984

Sept . 1985

Major E v e n t s i n t h e Development o f t h e W i s c o n s i n P o l i c y on P e s t i c i d e s i n Groundwater Event A l d i c a r b c o n f i r m e d i n W i s c o n s i n groundwater WDATCP proposed emergency r u l e L e g i s l a t i v e C o u n c i l Groundwater Management Study Committee formed Emergency r u l e adopted WDATCP was sued and c o u r t s u p h e l d r u l e WDATCP proposed permanent a l d i c a r b r u l e Permanent a l d i c a r b r u l e adopted 1983 W i s c o n s i n A c t 410, Groundwater Law, s i g n e d by Governor A. E a r l WDATCP proposed permanent f e r t i l i z e r s o r p e s t i c i d e s i n groundwater r u l e Permanent groundwater r u l e adopted

Union Carbide Agricultural Products Company, Inc. sells aldicarb—under t h e t r a d e name T e m i k — i n t h e S t a t e f o r use i n c o n t r o l l i n g i n s e c t p e s t s on p o t a t o e s . I n J u l y 1981, the p r e s e n c e of a l d i c a r b r e s i d u e s i n W i s c o n s i n groundwater was c o n f i r m e d i n a r e a s where t h e p e s t i c i d e had been used. The W i s c o n s i n Department of A g r i c u l t u r e , Trade and Consumer P r o t e c t i o n (WDATCP) promulgated an emergency r u l e which became e f f e c t i v e p r i o r t o t h e 1982 growing season. The m a n u f a c t u r e r and a g r o w e r s o r g a n i z a t i o n subsequently sued t h e S t a t e based on whether i t had a u t h o r i t y t o impose such a r u l e and whether t h e f a c t s s u p p o r t e d t h e d e c i s i o n s made by WDATCP. The suit—only t r i e d on t h e a u t h o r i t y question—was decided i n favor of the State. A t r i a l , based on t h e m e r i t s , would n o t have been c o n c l u d e d u n t i l a f t e r t h e emergency r u l e had t e r m i n a t e d which l e d t h e m a n u f a c t u r e r and growers t o drop t h e i r s u i t . Because a l d i c a r b was d e t e c t e d i n d r i n k i n g water samples i n W i s c o n s i n d u r i n g 1981, t h e S t a t e w i t h t h e c o n c u r r e n c e and a s s i s tance o f the manufacturer amended t h e use d i r e c t i o n s . This r e s u l t e d i n a f e d e r a l l a b e l amendment which changed t h e time t h a t a l d i c a r b c o u l d be l e g a l l y a p p l i e d t o p o t a t o e s from time o f p l a n t i n g to 4 t o 6 weeks a f t e r p l a n t i n g , reduced a p p l i c a t i o n r a t e s from 3 t o 2 pounds o f a c t i v e i n g r e d i e n t per a c r e , l i m i t e d use t o a l t e r n a t e y e a r s on any p i e c e o f l a n d , p l a c e d an e n v i r o n m e n t a l warning s t a t e ment on t h e l a b e l , and made t h e p r o d u c t a r e s t r i c t e d - u s e p e s t i c i d e . These r e q u i r e m e n t s were p l a c e d i n t h e S t a t e ' s emergency r u l e a l o n g w i t h p r o v i s i o n s r e q u i r i n g u s e r s t o f i l e a n o t i c e o f i n t e n t t o use the i n s e c t i c i d e and d e a l e r s to report s a l e s o f t h e Temik 15G a l d i c a r b f o r m u l a t i o n ; t h e s e r e s t r i c t i o n s a l s o became a p a r t o f a permanent a l d i c a r b r u l e . 1



494

EVALUATION O F PESTICIDES ING R O U N D

WATER

The emergency r u l e a l s o e s t a b l i s h e d moratorium a r e a s p r o h i b iting a l d i c a r b use wherever d e t e c t a b l e residues were found i n d r i n k i n g water w e l l s . Moratorium a r e a s under the emergency r u l e were l a n d p a r c e l s on which no a l d i c a r b c o u l d be u s e d . The moratorium a r e a s were e s t a b l i s h e d based on known c o n t a m i n a t i o n o f d r i n k i n g water and on a v a i l a b l e d a t a on d i r e c t i o n o f groundwater flow, depth t o the water t a b l e , water u s e , and a l d i c a r b u s e . A p p r o x i m a t e l y 70,000 a c r e s o f l a n d , some o f which was n o t i n a g r i c u l t u r a l p r o d u c t i o n , were i n c l u d e d under t h e moratorium. Although the emergency r u l e e x p i r e d i n J u l y 1982, a m o d i f i e d moratorium a r e a c o n c e p t was extended under the permanent r u l e . The moratorium on use remains i n e f f e c t u n t i l a l d i c a r b r e s i d u e s i n well samples remain below t h e enforcement s t a n d a r d f o r 1 y e a r . In 1983, WDATCP adopted a permanent r u l e (13) e s t a b l i s h i n g 10 ppb as the " a c t i o n l e v e l " which t r i g g e r s d e s i g n a t i o n o f a moratorium a r e a . L e g a l c o n c e r n s over t h e p u b l i c ' s p e r c e p t i o n o f how moratorium b o u n d a r i e s were e s t a b l i s h e d under t h e emergency r u l e l e d WDATCP t o e s t a b l i s h the b o u n d a r i e s as a c i r c l e o f 1-mile r a d i u s ( a p p r o x i m a t e l y 2800 a c r e s f o r each moratorium a r e a e s t a b l i s h e d from a single contamination s i t e ) around l o c a t i o n s where aldicarb residues exceeded the enforcement s t a n d a r d . The c e n t e r o f the moratorium a r e a i s t h e c e n t e r o f t h e q u a r t e r / q u a r t e r section of l a n d on which t h e w e l l i s l o c a t e d . T h e r e a r e 50 w e l l s l o c a t e d i n 25 q u a r t e r / q u a r t e r s e c t i o n s of l a n d which were c o n t a m i n a t e d w i t h a l d i c a r b r e s i d u e s above t h e 10 ppb l e v e l and were used t o e s t a b l i s h t h e 1985 a l d i c a r b moratorium a r e a s ; 33 w e l l s c u r r e n t l y a r e over t h e g u i d e l i n e l e v e l . Because o f o v e r l a p p i n g , t h e s e s i t e s e s t a b l i s h 11 moratorium a r e a s encompassing 36,500 a c r e s . W e l l owners have been i n f o r m e d o f l e v e l s o f contami n a t i o n and a d v i s e d t o seek a l t e r n a t e water s u p p l i e s u n t i l the c o n t a m i n a t i o n l e v e l s drop below the g u i d e l i n e l e v e l , o r new w e l l s can be i n s t a l l e d . Under s e p a r a t e r u l e s o f the S t a t e , some owners q u a l i f y f o r a compensation fund as a r e s u l t o f t h e p r e s e n c e o f aldicarb i n their wells. O n l y r e c e n t l y has the a u t h o r i t y been g r a n t e d t o c l o s e p r i v a t e w e l l s ; t h e a u t h o r i t y has n o t been e x e r cised. S i n c e 1982, 12 o f t h e 75 owners whose w e l l s exceeded the 10 ppb l e v e l have t a k e n advantage o f t h e a l d i c a r b m a n u f a c t u r e r ' s o f f e r t o pay f o r b o t t l e d water. About 40% o f t h e 51 p r i v a t e w e l l owners who have been o f f e r e d c a r b o n f i l t e r s have a c c e p t e d ( 6 ) . D e s p i t e t h e WDATCP r u l e , a l d i c a r b r e s i d u e s a r e s t i l l present i n groundwater a l t h o u g h c o n t a m i n a t i o n l e v e l s o f most w e l l s w i t h i n moratorium a r e a s a r e d e c r e a s i n g w i t h t i m e . However, s i n c e a l d i c a r b residues are s t i l l detectable, the S t a t e ' s public intervenor—a Wisconsin A s s i s t a n t Attorney General with r e s p o n s i b i l i t y f o r e n v i ronmental p r o t e c t i o n — a n d some S t a t e l e g i s l a t o r s , environmentalists and concerned c i t i z e n s b e l i e v e the r u l e i s i n e f f e c t i v e . In their view, t h e r e m e d i a l a c t i o n taken by WDATCP s h o u l d a l s o r e c t i f y an already e x i s t i n g c o n d i t i o n , w h i l e WDATCP r e g a r d s the r e m e d i a l a c t i o n as p r o t e c t i o n f o r t h e f u t u r e , p r o v i d i n g c l e a n s i n g time f o r the past c o n d i t i o n s but not a c l e a n u p program per se* S t a f f of WDATCP recognize that protection and c l e a n u p efforts require decades rather than months. Some members o f the p u b l i c a r e demanding immediate d e c o n t a m i n a t i o n o f an i n a c c e s s i b l e resource, and r e t r i b u t i o n i n t h e form o f s t r i c t liability f o r practices performed b e f o r e t h e e x i s t i n g c o n d i t i o n s were r e c o g n i z e d .


28.

EHART ET AL.


495

Meanwhile, growers have become more s u p p o r t i v e of proper r e g u l a t i o n o f p e s t i c i d e p r o d u c t s which have a p o t e n t i a l t o r e a c h groundwater. They a r e c o n c e r n e d about water q u a l i t y as i t a f f e c t s t h e i r f a m i l i e s , l i v e s t o c k and economic f u t u r e . They have adopted i r r i g a t i o n p r a c t i c e s t o reduce e x c e s s i v e water u s e which p r e v i o u s l y they c o n s i d e r e d u n n e c e s s a r y even though e c o n o m i c a l l y advantageous. They have, w i t h few e x c e p t i o n s , f i l e d n o t i c e s o f i n t e n t t o a p p l y aldicarb. They have c o o p e r a t e d w i t h field i n v e s t i g a t i o n s and s a m p l i n g o f s o i l , groundwater and produce f o r a l d i c a r b r e s i d u e s .


Development, Administration Groundwater Law

and

Enforcement

of

the Wisconsin

For a 2-year p e r i o d , c o n c u r r e n t w i t h t h e development and a d m i n i s t r a t i o n o f t h e a l d i c a r b r u l e by WDATCP, t h e W i s c o n s i n L e g i s l a t u r e s t u d i e d and r e f i n e d the l e g a l framework f o r a S t a t e groundwater p r o t e c t i o n program. A l t h o u g h d e s c r i b e d by many t o be a comprehensive groundwater protection program, t h e groundwater law (14) signed i n May 1984 added little authority to existing State programs; i t merely c o d i f i e d many e x i s t i n g and emerging e f f o r t s o f S t a t e a g e n c i e s t o p r o t e c t groundwater. The l e g i s l a t i v e a c t i o n i s important because i t e s t a b l i s h e s the mechanism t o use " h e a l t h advisory" levels as S t a t e "enforcement standards" not t o be a t t a i n e d o r exceeded i n groundwater. I t also defines a "preventive a c t i o n l i m i t " as a f r a c t i o n o f t h e enforcement s t a n d a r d . This i s a contaminant c o n c e n t r a t i o n f o r s u b s t a n c e s found i n groundwater where some agency a c t i o n i s r e q u i r e d . The law e f f e c t s a change i n p o l i c y from t h e s t r i c t n o n d e g r a d a t i o n p h i l o s o p h y o f t h e p a s t — w h e r e a c t i o n was not mandated as a s t a t u t o r y r e q u i r e m e n t — t o a new n u m e r i c a l s t a n d a r d p o l i c y , where an agency d e c i s i o n , even i f i t chooses t o do n o t h i n g , must be j u s t i f i e d and a r t i c u l a t e d . T h i s i s a major change in public policy. I t s importance i s t h a t i t a s s u r e s better, a l t h o u g h not n e c e s s a r i l y a b s o l u t e , p r o t e c t i o n o f t h e groundwater resource. However, t h i s assurance i s not yet recognized or a p p r e c i a t e d by t h e g e n e r a l p u b l i c . The l e g i s l a t i o n was needed t o d e f i n e t h e i n s t i t u t i o n a l r e s p o n sibilities o f t h e W i s c o n s i n S t a t e a g e n c i e s w i t h a mandate t o p r o t e c t groundwater. However, i t s t i m i n g had d e t r i m e n t a l e f f e c t s on WDATCP s e f f o r t s t o conduct an e f f e c t i v e aldicarb control program. The WDATCP needed answers t o s e v e r a l q u e s t i o n s t o a d d r e s s the problem o f groundwater c o n t a m i n a t i o n by a l d i c a r b r e s i d u e s i n an informed, r e s p o n s i b l e f a s h i o n . F o r example, many o f the r e a s o n s t h a t a l d i c a r b r e s i d u e s move t h r o u g h t h e vadose zone t o groundwater were n o t u n d e r s t o o d and a r e s t i l l i n a d e q u a t e l y r e s e a r c h e d . The S t a t e d i d not p r o v i d e adequate r e s e a r c h f u n d i n g because t h e L e g i s l a t u r e was g r a p p l i n g w i t h what the S t a t e ' s g e n e r a l groundwater p o l i c y should be. I r o n i c a l l y , t h e S t a t e modeled i t s groundwater p o l i c y on the a l d i c a r b r u l e ; no S t a t e d o l l a r s , however, were made a v a i l a b l e d i r e c t l y f o r r e s e a r c h , even though f r e q u e n t l e g i s l a t i v e inquiries c o n t i n u e t o demand p r o o f that the a l d i c a r b rule i s working t o m i n i m i z e o r e l i m i n a t e f u r t h e r i n t r u s i o n o f a l d i c a r b r e s i d u e s i n t o groundwater. The c u r r e n t S t a t e program r e q u i r e s each agency t o p r i o r i t i z e potential groundwater pollutants under i t s jurisdiction. The W i s c o n s i n Department o f N a t u r a l Resources (WDNR) i s r e q u i r e d t o 1



496

EVALUATION O F PESTICIDES ING R O U N D WATER

m o n i t o r groundwater t o a s s e s s problems caused by these p r i o r i t y substances. I f p e s t i c i d e r e s i d u e s a r e found i n groundwater, WDNR w i l l f o r w a r d t h e d a t a t o WDATCP. When WDATCP determines t h a t a practice r e g u l a t e d by WDATCP i s r e s p o n s i b l e f o r t h e p e s t i c i d e r e s i d u e s and when t h e l e v e l o f any p e s t i c i d e a t t a i n s o r exceeds a preventive action limit o r enforcement standard, c e r t a i n sites p e c i f i c a c t i o n s must be t a k e n and/or r u l e s must be promulgated t o modify management p r a c t i c e s . Changes i n p r a c t i c e s must be monit o r e d f o r e f f e c t i v e n e s s t o m i n i m i z e impacts on groundwater q u a l i t y . The WDATCP w i l l p e r f o r m t h i s f u n c t i o n t o t h e e x t e n t t h a t f i n a n c i a l resources are a v a i l a b l e . The WDATCP r u l e ( 1 5 ) — e s t a b l i s h i n g a r e g u l a t o r y program f o r fertilizers or pesticides i n groundwater—became effective i n September 1985. C o n t a i n e d i n t h e r u l e a r e p r o v i s i o n s f o r WDATCP action following notification o f confirmed pesticide residue c o n t a m i n a t i o n o f groundwater, a d e s c r i p t i o n o f t h e agency's i n v e s t i g a t i o n a l p r o c e d u r e s , methods f o r i d e n t i f i c a t i o n o f w e l l l o c a t i o n s where n u m e r i c a l s t a n d a r d s w i l l be a p p l i e d , and a s e l e c t i o n o f s i t e s p e c i f i c r e s p o n s e s t o be e x p e c t e d when c o n t a m i n a t i o n e x i s t s . The agency i s also committed t o promulgate specific rules f o r s u b s t a n c e s f o r which an enforcement s t a n d a r d has been e s t a b l i s h e d . Memorandum o f U n d e r s t a n d i n g . Another important p r o v i s i o n i n the r u l e i s t h e e s t a b l i s h m e n t o f a memorandum o f u n d e r s t a n d i n g between WDATCP and WDNR r e g a r d i n g sample h a n d l i n g and a n a l y s i s . I n the past, p r e l i m i n a r y , unconfirmed, analytical data intended f o r program p l a n n i n g was r e l e a s e d t o t h e p u b l i c . In a d d i t i o n the lack of a specific protocol f o r sample handling raised questions r e g a r d i n g t h e c o m p a r a b i l i t y and r e l i a b i l i t y o f some d a t a . The WDATCP and WDNR s t a f f r e c o g n i z e d t h a t l a b o r a t o r y p r o t o c o l s under p e s t i c i d e r e g u l a t o r y programs d i f f e r from those conducted under mandatory f e d e r a l water programs. Agreeable, uniform p r a c t i c e s t o d e a l w i t h t h e s e d i f f e r i n g approaches t o q u a l i t y a s s u r a n c e needed t o be e s t a b l i s h e d and a r e p a r t o f t h e memorandum o f u n d e r s t a n d i n g . The memorandum o f u n d e r s t a n d i n g c o n t a i n s a d e s c r i p t i o n o f a c c e p t a b l e c o l l e c t i o n equipment and c o n t a i n e r s , c o l l e c t i o n p r o c e d u r e s , r e c o r d k e e p i n g r e q u i r e m e n t s , use o f c o n t r o l samples, sample size, storage ( i . e . , temperature and p r e s e r v a t i o n ) and c u s t o d y requirements. I t e s t a b l i s h e s a r e q u i r e m e n t f o r t h e maintenance o f a q u a l i t y a s s u r a n c e manual and an a p p r o v a l p r o c e s s f o r a n a l y t i c a l methods d e t a i l i n g l i m i t s o f d e t e c t i o n ( q u a l i t a t i v e ) and l i m i t s o f quantification. The memorandum o f u n d e r s t a n d i n g a l s o d e f i n e s when c o n f i r m a t o r y a n a l y s i s by a n o t h e r method o r c h r o m a t o g r a p h i c column i s n e c e s s a r y , and r e q u i r e s development o f r e l i a b l e i n f o r m a t i o n on w e l l c o n s t r u c t i o n and depth i n t h e a q u i f e r and a l l o w s f o r t h e development o f a l t e r n a t i v e p r o t o c o l s f o r sampling and h a n d l i n g when s p e c i f i c substances r e q u i r e i t . T h i s p r o c e s s may seem unduly b u r e a u c r a t i c and u n n e c e s s a r y . However, i f governmental programs a r e t o be c r e d i b l e , e x a c t i n g p r o t o c o l s must be e s t a b l i s h e d and adhered t o . E d u c a t i o n o f t h e p u b l i c on t h e need f o r t h e s e programs and g e n e r a l e d u c a t i o n on groundwater a r e needed t o i n c r e a s e f a c t u a l awareness. The i n e x p e n s i v e method o f c u t t i n g c o r n e r s and n o t a s s u r i n g t h e q u a l i t y o f program e f f o r t s has c o s t f a r more i n c r e d i b i l i t y than t h e c o s t t o r u n programs p r o p e r l y . Without such e x p e n d i t u r e s t o s e c u r e q u a l i t y


28.

EHART ET AL.

497


a s s u r a n c e , the c r e d i b i l i t y o f s c i e n t i f i c making w i l l not be m a i n t a i n e d .

data

in public

decision-


Mathematical Models. U s i n g models t o a i d i n e v a l u a t i n g the p o t e n tial f o r groundwater c o n t a m i n a t i o n has been emphasized. Many b e l i e v e t h a t models s h o u l d be used as p a r t o f a r e g u l a t o r y approach to p r e v e n t f u t u r e c o n t a m i n a t i o n . Models are a u s e f u l t o o l f o r d e t e r m i n i n g p o t e n t i a l p r i o r i t i e s and p o s s i b l e s e n s i t i v e a r e a s and crop uses and i n d e v e l o p i n g m o n i t o r i n g p l a n s . However, models a r e not sufficiently reliable and predictive to a l l o w r e g u l a t o r y a c t i o n s to be taken on the b a s i s of model f i n d i n g s a l o n e . Theref o r e , a l t h o u g h u s e f u l i n r e s e a r c h and p l a n n i n g , models are not y e t s u f f i c i e n t l y s o p h i s t i c a t e d to be used as a b a s i s f o r r e g u l a t o r y programs. Enforcement. No groundwater p r o t e c t i o n program w i l l be e f f e c t i v e w i t h o u t p r o p e r enforcement. S u r v e i l l a n c e of p e s t i c i d e uses w i l l i n c r e a s e as more management c r i t e r i a are added t o l a b e l d i r e c tions . Compliance w i l l r e q u i r e improved e d u c a t i o n of u s e r s and changes i n s o c i a l a t t i t u d e s . C a l i b r a t i o n o f a p p l i c a t i o n equipment, always a d i f f i c u l t p r o c e d u r e and s u b j e c t t o i n d i v i d u a l e r r o r , w i l l need more c r i t i c a l a t t e n t i o n . The i n c r e a s e d p o t e n t i a l f o r l e g a l c h a l l e n g e o f d e c i s i o n s w i l l cause enforcement a g e n c i e s t o spend more r e s o u r c e s on each investigation. This w i l l entail more e x t e n s i v e r e c o r d k e e p i n g and more d e t a i l e d r e p o r t i n g . The r e l i a b i l i t y of c u r r e n t l y a v a i l a b l e t e c h n o l o g y f o r e s t a b l i s h i n g and a d m i n i s t e r i n g these p o l i c i e s , must be a s s u r e d o r the system i s u s e l e s s . There must be a c c u r a t e and r e a d i l y a v a i l a b l e i n f o r m a t i o n t o e s t a b l i s h enforcement s t a n d a r d s f o r the p e s t i c i d e p r o d u c t s i d e n t i f i e d as h a v i n g the p o t e n t i a l to r e a c h groundwater. Enforcement o r r e g u l a t o r y a c t i o n s cannot be f a i r w i t h o u t a c c u r a t e a n a l y t i c a l data. Knowledge of p e s t i c i d e u s e s , g e o l o g y , hydrog e o l o g y and environmental f a t e are needed to p r e d i c t potential problems, and more i m p o r t a n t l y , t o e s t a b l i s h a r e a s o n a b l e , c o s t effective monitoring program (16). Programs which provide i n c e n t i v e s and proper enforcement are needed t o make the system effective. A system which a s s u r e s t h a t a g e n c i e s tend t o the b u s i n e s s of a d m i n i s t e r i n g and academic i n s t i t u t i o n s tend t o the business of r e s e a r c h must be developed; r e s e a r c h e r s must be r e s p o n s i v e to r e g u l a t o r y i s s u e s . W i s c o n s i n has made some s t r i d e s a t d e v e l o p i n g a system which i s t e c h n i c a l l y sound and p r a c t i c a l l y w o r k a b l e but more needs t o be done. V i o l a t i o n s o f s t a t e laws and r u l e s which r e s u l t i n groundwater c o n t a m i n a t i o n must be p r o s e c u t e d by t r a d i t i o n a l methods. However, to a c c e l e r a t e p r o t e c t i o n programs, some i n n o v a t i v e c o s t i n c e n t i v e s a r e needed. When the i n f o r m e d p u b l i c and a f f e c t e d i n d u s t r i e s a r e a c t i v e p a r t i c i p a n t s i n the d e c i s i o n - m a k i n g p r o c e s s , the law i s more s t r i c t l y adhered t o . The examples detailed i n this paper are from Wisconsin. Geographical, climatological, legal and political variabilities exist i n other states which may r e q u i r e m o d i f i c a t i o n of the Wisconsin procedures before t h e s e methods o f l a n d management c o n t r o l s can be adopted by o t h e r s t a t e s .


498

EVALUATION O F PESTICIDES IN G R O U N D

WATER

Literature Cited 1. 2. 3.


4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

Holden, P., personal communication. "Groundwater Contamination, The Measure of Public Concern"; Center for Communication Dynamics, Washington, D.C., 1985. Wood, D. "Wisconsin Environmental Priorities Survey Results." Environ. Priorities Conf., Madison, Feb. 14, 1983. Business Week, Jan. 24, 1983. p. 87. Francis, J., personal communication. Back, R., personal communications. Francis, J . ; Larson, O. III. National Statistical Assessment of Rural Water Conditions. Executive Summary. Cornell University, Ithaca, 1983. Zahradnik, F. The New Farm Jan. 1984, 30-31. Cohen, S., personal communication. Zaki, M.; Moran, D.; Harris, D. Am. J. Public Health 1982, 72, 1391-1395. Orloff, N. "We Scoff at Big Risks and Scotch Small Ones." Wall Street J., Dec. 3, 1984, p. 34. Schierow, L . - J . ; Chesters, G. Water Resources Bull. 1983, 19, 107-114. WDATCP. Aldicarb Use Restrictions; Reporting Requirements. Chapter Ag 29.17, Wis. Admin. Code. 83 Wis. Act 410. Laws of Wis., 1983. WDATCP. Fertilizer or Pesticide Substances in Groundwater: Regulatory Program. Chapter Ag 161, Wis. Admin. Code. Ehart, O. R. Unpublished presentation. Entomol. Soc. Am., Detroit, Nov. 29, 1983.

RECEIVED March 25, 1986


Evaluation of Pesticides in Ground Water - ACS Publications

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