1 **F e**  **de r**  **al F**  **oo d**  **, D r**  **u g, a**  **n d**  **Cos m**  **e t**  **ic A**  **c t**  **( FFD**  **C A)**  **Co n**  **si d**  **er a**  **t io**  **n s for**  **Pseudomonas fluorescens strain D7**  **Do c**  **k e**  **t ID N**  **u m**  **be r**  **: E**  **PA -**  **HQ -**  **OPP -**  **201 3**  **- 0**  **569**

**Da te**  **: August 22**  **, 2 01**  **4** S ec tion 408 (c)( 2 )( A ) ( i) o f F F D C A a llows the E P A to e st a blish an e x e mption fr om the re qui r e m e nt f or a tol eran c e ( the l e g a l limit f or a p e sti c ide c h e mi c a l r e sidue in or on a f oo d ) o n l y if the E P A d e t er min e s th at the e x e mption is “ s afe .” S ec tion 408 (c)( 2 )( A ) ( ii) of F F D C A d ef i n e s “ s a f e ” to m ean th at “ th e r e is a rea son a b l e c e rt a int y th at no h ar

m will re sult fr om a ggr e g at e e x posur e to the p e sti c ide c h e mi ca l re s i du e, in c luding a ll anti c ip at e d di e t ar y e x posure s and a ll oth e r e x posu re s f or whi c h th er e is re li a

ble i n f o r m ation.” This in c lud e s e x posur e thr ou gh dr inking w at e r an d in re sid e nti a l s e ttin g s b ut do e s not in c lude o cc u p ation a l e x posure . P ur su ant to F F D C A s ec tion 408 (c ) ( 2 ) ( B ) , in e st a blishing or m a i n t a ining in e f fec t an e x e mption fr om the re qui r e m e nt of a tol eran c e , the E P A mu s t t ake into acc ount the f a c to r s s e t f

o rth in F F D C A s ec tion 408 (b )( 2 ) ( C ) , whi c h r e qu i r e the E P A to g i v e sp ec i a l c onsid eration to e x posur e of in fants and c hildr e n to the p e sti c ide c h e mi c a l re sid

u e in e st a blishing a tol e ran c e e x e mption, and to “e n sur e th at th er e is a r e a so n a ble cert a int y th at no h ar

m will re sult to in fants and c hildre n fr om a ggr e g at e e x posur e to the p e sti c ide c h e mi ca l re sidu e ....” Addition a l l y, FF D C A s ec tion 408 (b ) ( 2 )( D) r e qui re s th at the E P A c onsid e r “ av a il a ble in f o r m ation c on c e r ning the c umul ative e f

fec ts o f [ a p arti c ul ar p e sti c id e ' s]
. . . re sidu e s and oth e r subst an ce s th at h ave a c ommon m e c h anism of to x i c i t y .” The E P A p erf

o r ms a numb e r of an a l ys e s to d e t e rmine the r isks fr om a g gr e g ate e x posur e to p e sti c i de re sidu e s. F i r st, the E P A d e t er

min e s the to x i c i t y o f p e sti c id e s. S ec ond, the E P A e x a min e s e x posur e to the p e sti c ide thr o u gh f ood, dr inking w at er , and thr o u gh oth e r e x posure s th at o c c ur a s a re sult of p e sti c i d e use in re sid e nti a l s e ttin g s. **I. S** **u m**  **m ary**  **of P** 

**e titio**  **n e** **d -**  **f or Tol**  **e ra**  **n c**  **e E**  **x e** **m ption**  In the F e d e r a l R e g ist e r of September 12, 2013 (78 FR 56185) (FRL

- 93 99
- 7 ), the EPA issu e d a noti c e pur s u ant to F F D C A s ec tion 408 ( d )( 3 ) , 21 U. S
. C . 346 a( d )( 3 ) , announ c i ng the f ili n g of a p e sti c i d e tol eran c e p e tition ( P P 2F8103 ) by Northwest Agricultural Products 821 South Chestnut Avenue, Pasco, WA 99301
. The petition re qu e s t e d th at 40 C F R p art 180 be am e nd e d b y e st a blishing an e x e mption fr om the re qui re m e nt of a tol e r an c e f

or r e sidu es of Pseudomonas fluorescens strain D7 in or on growing crops and rangeland . The noti c e r e fere n ce d a summ ar y of th e p e tition p re p ar e d b y the p e tition er , Northwest Agricultural Products , whi c h is av a i l a

ble in Do c k e t ID Numb e r E P A
- H Q
- O PP
- 2013
- 0569 via http : // www . re gulations. g

o v . While rangeland is not a food commodity and “growing crops” is not a recognized commodity term used by

the Agency in tolerance actions, the Agency is interpreting the petitioner’s request as seeking a tolerance exemption for “all food commodities
. ” The term “growing crops” is quite broad and does not limit that ty pes of food commodities that it covers; therefore, the Agency believes a reasonable interpretation of that term allows for establishment of an exemption from the requirement of a toleranc e for “all food commodities
. ” One comment concerning the general impact of pesticides on bees was filed in the Pseudomonas fluorescens D7 docket. T he comment is not relevant to this tolerance action as the comment does not concern the safet y of this microbe or have any bearing on the Agency ’s assessment under section 408 of the FFDCA.2 **II. Toxi** **c ologi** **c al Pro** 

**f ile**  C onsist e nt with s ec tion 4 08 (b )( 2 ) ( D) of F F D C A, t he E P A re vi e w e d the av a il a ble s c i e nti f

ic d ata and oth er re l e v ant in f

o r m ation on Pseudomonas fluorescens strain D7 , and c onsid e r e d its v a lidi t y, c ompl e t e n e ss, and re li a bili t y, a s w e ll a s the re l ationship of this in f o r m ation to hum an r isk. The E P A a lso c onsid e r e d av a il a ble in f o r m ation c on c e r

ning t he v ar i a

bili t y o f the s e ns i tiviti e s of m a jor id e nti f

i a ble sub gr oups o f c onsum er s, in c luding in fants and c hildre n. **A . O**  **ve r** **v i** **e w**  **of Pseudomonas fluorescens strain D7**  The D7 EP is for use as an herbicide in the United States in field applications for suppression of downy b rome (cheatgrass), m edusahead, Japanese brome, and j ointed g oatgrass on fields of turf and grasses grown for seed, alfalfa; wheat, barley , triticale, oat, and rangeland. It is for application as a seed treatment and by ground or aerial spray

to listed field sites. The D7 EP is to be applied directly to the soil surface, in autumn or spring when temperatures are cooler, and the plants are in preemergence. P. fluorescens occurs naturally in soil and water ( Ref. 1 ), and strain D7 is a root

- associated bacterium which was isolated originally

from winter wheat roots from the West Coast region of the United States. **B .**  **Microbial P** 

**e sti** **c ide**  **Toxi c**  **ology Data**  **R e**  **q u**  **ir e** **m e** **n ts**  All a ppli ca ble m amm a li an to x i c ology d ata re qui r e m e nts suppo rting the r e qu e st f or an e x e mption fr o m the re qui re m e nt of a tol er an c e f or r e sidu e s of Pseudomonas fluorescens strain D7 i n or on a ll food c ommoditi e s h ave b e e n f

ul f ill e d with d ata submitt e d b y the p e tition e r or scientific rationale
. The to x i c i t y and pathogenicity t e sts ( d er

m a l, to x i c i t y

) and i rr it ation t e sts (ac ute e y e and p r im ar y d er

m a l i rr it ation) th a

t a d dre ss pot e nti a l r out e s of e x posur e to the ac tive i n gr e di e nt ar e a ll c l a ssi f i e d in To x i c i t y C at e g o r y I V ( s e e below or Re f

. 2, 3 and 4 ) and re v ea l e d little to no to x i c i t y attr ib u t e d to Pseudomonas fluorescens strain D7

. F in a l l y , the p e tition e r re po rt e d th at no h y p e r s e nsitivi t y in c id e nt s o cc ur r e d dur i n g the r e s earc h, d e v e lopm e nt, and t e sting of this active ingredient
. The ov e r a ll c on c lusions f r om a ll to x i c olo g i ca l in f

o r m ation submitt e d b y the p e tition e r ar e b r i ef l y d e s cr ib e d b e low, and mo r e in

- d e p th s y nops e s of stu d y r e su l ts can be f ound in the a sso c i at e d draft Biopesticides Registration Action Document ( BRAD ) for Pseudomonas fluorescens strain D7 , p r ovid e d a s a r e f e r e n c e in S ec tion VII o f this do c um e nt ( R ef
. 2 ). 1. **Acute Injection Toxicity/Pathogenicity**

**– Rat**  (MRID 49349701) A study was repeated to re - evaluate the acute intravenous toxicity infectivity

and pathogenicit y, of a microbial pest control agent (MPCA), Pseudomonas fluorescens D7, at a single exposure of 10 6 and 10 7 doses. The MPCA test substance, inactivated MPCA, or sterile filtrate was injected into the tail vein of one of four groups of rats. A control group (untreated) was conducted concurrently. The animals were observed f requentl y on day of dosing for mortality and signs of pharmacological and/or toxicological effects and once daily thereafter for 21 day s. Tissue and blood samples taken at interim sacrifices from the group receiving the active test substance were cultured to provide quantitative measurements of the test microbe's clearance pattern. There was no mortality in an y group during the stud y. During observations for clinical signs, all animals appeared normal for the duration of the study . The gross necrops y condu cted at termination of the study revealed no observable abnormalities. The test organism had cleared completely from Groups IV and V (MPCA) blood, kidney s, mesenteric l ymph nodes, lungs, and brain, liver, spleen and cecum contents by Day 7. After two conse cutive interim sacrifices showed no growth of test organism in the organs plated, no further3 tissue samples were taken. The test substance Pseudomonas fluorescens D7 was determined to be non

- toxic and not pathogenic or infective to rats when injected intr avenousl y at a dose of 3.4 x 10 7 CFU/rat or 3.7 x 10 6 CFU/rat. EPA determined this study to be acceptable This study

(MRID 49349701) addresses EPA recommendations to repeat an acute injection toxicity study using a l ower dose of the microorganisms that includes additional controls such as filtered culture medium, and autoclaved medium to account for the observed injection results. This study supersedes the previously submitted acute injection toxicity /pathogenicit y in rat study (MRID 48966402) that tested Pseudomonas fluorescens strain D7 and showed adverse effects to rats following a single intravenous injection administration of 1.3 x 10 8 CFU/rat including mortality , abnormal clinical signs; transient weight loss, abnormal gross necrops y findings, and altered organ weights. 2. **Acute Oral Toxicity/Pathogenicity**

**– Rat**  (MRID 48966403) Sprague
- Dawley

rats, 8 week old, (12/sex) were given a single oral dose of M PCA Pseudomonas fluorescens s train D7 of 1.3 X 10 9 CFU/animal. The animals were observed three times on day 0 after dosing and daily through day

21 with interim scheduled sacrifices on Day s 3, 7, and 14. Five males and five females were treated with autoclaved Pseudomonas fluorescens s train D7 as inactiv e MPCA controls, two untreated animals per sex were used as “shelf controls,” and two animals per sex were designated as untreated controls. No observable abnormalities were found during observations for clinical signs or at necropsy , and there were no to xicologically

relevant differences between the body weights of the treated animals and those of controls. Relative to their respective controls, MPCA

- treated females had increased relative liver weights (+16.0%; p<0.05), and MPCA

- treated males had increas ed relative spleen weights (+16.7%; p<0.05), and these differences correlated with increased mean absolute weights of these same organs (+11.7% and +27.1% for MPCA
- treated female absolute liver and MPCA

- treated male absolute spleen weights, respectively). No CFUs (or in one instance a single individual count of <100 CFU/g) were recovered from the brain, lungs, liver, kidney s, or ly

mph nodes of any

active

- treated animal. Pseudomonas fluorescens s train D7 was found in feces, urine, and cecum contents of MCP A
- treated animals and appeared to be completel y cleared b y day 14 following oral administration to rats. Based on the results of this study , Pseudomonas fluorescens s train D7 does not appear to be toxic, infective, and/or pathogenic in rats, when dosed at 1.3 X 10 9 CFU/animal. The EPA rated this study

as acceptable.
3. **Acute Pulmonary Toxicity/Pathogenicity**

**– Rat**  (MRID 48966404) Groups of 12 week old Sprague Dawley rats (3/sex/Group) were exposed by the intratracheal route to Pseudomonas fluorescens s train D7 in sterile PBS at a constant dose volume of 0.1 mL/ animal and a dose of 4.6 x 10 8 cfu/animal. Eight males and eight females were treated with autoclaved Pseudomonas fluorescens s train D7 as autoclaved controls; five males and five females were not tre ated and used as untreated control; and four males and four females were not treated and used as shelf controls. The animals were then observed for up to 21 day s, with interim sacrifices on day 0 (all groups) and day s 3, 7, and 14 (active

- MCPA group). There were no test substance related clinical signs, gross necrops y findings, or differences in organ weights. Two males in the active test material treated group sacrificed on day 3 lost weight and one female in autoclaved test material treated group sa crificed on day 21 did not gain weight during the first week but gained weight b y da y 14. All other animals gained weight prior to scheduled sacrifice. The test organisms were not seen or were present at < 100 cfu/g in lungs from the animals sacrificed a fter dosing on day 0. The test organisms were not seen or were present at < 100 cfu/g in blood, brain, lungs, spleen, liver, kidney s,4 mesenteric l ymph nodes, and cecum content removed from animals sacrificed on day s 3 and 7. Based on these results, Pseudomonas fluorescens s train D7 does not appear to be toxic, infective, and/or pathogenic in rat, when dosed at 4.6 x 10 8 cfu /animal . The EPA rated this study as acceptable. 4. **Acute Dermal Toxicity/ Pathogenicity** 

**– Rabbit**  **(** MRID 48966405) Five male and five female New Zealand White rabbits, 16

- 18 weeks old, were dermall y exposed to a 2000 mg/kg bw dose of Pseudomonas fluorescens s train D7 moistened with 2.0 mLof deionized water/g test substance for 24 hours to an area of approximately 10% of bod y surface area. Following exposure, the animals were observed for a period of 14 day s. All animals survived and had no abnormal s ys temic clinical signs during the stud y. Very slight to well

- defined Ery thema was noted on all dose sites on day 1 and re solved b y da y 4. With the exception of one female that lost weight during the second week, all animals gained weight throughout the study
. No observable abnormalities were found at necrops y. The d ermal LD 50 for m ales was greater than 2000 mg/kg bw; for f emales was greater than 2000 mg/kg bw; and for both sexes c ombined was greater than 2000 mg/kg bw. Based on the results of this study , Pseudomonas fluorescens Strain D7 is of low toxicity **.** EPA classified the acute dermal toxicity of Pseudomonas fluoresc ens s train D7 as Toxicity

Category I V and rated this study

as acceptable. 5. **Primary Eye Irritation**

**– Rabbit**  (MRID 49100801) 100 mg of undiluted Pseudomonas fluorescens s train D7 (Batch No. 201109210301 ; purity 95%; pH not reported) was instilled as supplied into the conjunctival sac of the right ey e of three male and three female New Zealand White rabbits. Untreated left ey es served as controls. Animals were observed at 1, 24, 48, and 72 hours after test material instillation. Irritation was score d by the method of Draize and classified by the sy stem of Kay

and Calandra. No corneal opacit y, iritis, or conjunctival irritation was noted on an y rabbit throughout the stud y. Pseudomonas fluorescens s train D7 was not irritating to the ey e and EPA classi fied the acute ey e irritation as Toxicity Category I V for primary

ey e irritation. The EPA rated this study as acceptable. 6. **Primary Dermal Irritation**

**– Rabbit**  (MRID 49100802) Three male and three female New Zealand White rabbits were dermally exposed to 500 mg of Pseudomonas fluorescens s train D7 moistened with 1.0 mLof DI water for 4 hours on an approximately 2.5 x 2.5 cm area of the bod y surface. The animals were observed at 1, 24, 48, and 72 hours after patch removal. Irritation was scored b y the method of Draize. No dermal irritation was noted on an y animal during the stud y. The primary irritation index was 0.0. Pseudomonas fluorescens s train D7 was not irritating and E PA classified the dermal irritation toxicity

as Toxicity

Category I V. The EPA rated this study as acceptable. 6. **H y**  **p e** **rs e** **nsiti v** **ity in**  **c id** 

**e nts**  The p e tition e r re po rt e d th at no h y p er s e n sitivi t y in c id e nts, in c lud i ng imm e di at e - t y p e or d e l a ye d

- t y

pe re a c tions of hum ans and dom e stic anim a ls, o c c urre d d ur ing re s e ar c h, d e v e lopm e nt, or t e sti n g of Pseudomonas fluorescens s train D7 ( R ef
. 2 )
. **III. A** **ggr e** 

**gate E**  **xpos u**  **r e**  In examining aggregate exposure, section 408 of FFDCA directs EPA to consider available information concerning exposures from the pesticide residue in food and all other nonoccupational exposures, including drinking water from ground water or surface water and exposure through pesticide use in gardens, lawns, or buildings (residential and other indoor us es).5 Food Exposure and Risk Characterization : The EPA found that increased d ietary exposure to Pseudomonas fluorescens strain D7 a naturally occurring bacterium is anticipated to be negligible For the proposed use of Pseudomonas fluorescens strain D7 as an herbicide, the applications are made before crop plants emerge, or as seed treatment and consequently oral exposure to residues from such use is expected to be minimal. Pseudomonas fluorescens strain D7 and other closely related Pseudomon as fluorescens bacteria already exist in the soil environment. The EPA concluded that the risk posed to adults, infants, and children is likely to be minimal because of the low acute oral toxicity /pathogenicity

potential of Pseudomonas fluorescens strain D7. Drinking W

ater Exposure and Risk Characterization : Exposure to residues of Pseudomonas fluorescens strain D7 in consumed drinking water is not likely to increase because there are no use sites for the pesticide with direct applications to water. The re is a possibility of spray drift from aerial applications or runoff of prepared fields and rangelands into surface waters. Ground water is not expected to have significant exposure to Pseudomonas fluorescens strain D7 since, like other microorganisms, thi s microbial pesticide would likely be filtered out b y the particulate nature of man y soil ty pes. If it were to be transferred to surface or ground waters that are intended for eventual human consumption (e.g., through spray drift or runoff) and directed to wastewater treatment sy stems or drinking water facilities, it likely would not survive the conditions water is subjected to in such sy stems or facilities, including chlorination, pH adjustments, filtration, and/ or occasionall y high temperatures ( Ref 5 , 6 and 7 ) . In the remote likelihood that Pseudomonas fluorescens strain D7 is present in drinking water (e.g., water not subject to treatment s ys tems or facilities), its target pest specificit y and available data indicate no toxicity and/or pathogenicit y is likely to occur with any

drinking water exposure to Pseudomonas fluorescens strain D7 that results from pesticide applications made in accordance with good agricultural practices ( s e e a ddit i on a l dis c ussion in S ec tion I I of this do c um e nt )
. Non

- occupational, Residential Risk Characterization : Given that Pseudomonas fluorescens strain D7 use sites do not include residential settings and because the bacterium is naturally

- occurring EPA determined that non - occupational exposure to the bacterium is unlikely . Repeated exposures to the Pseudomonas fluorescens strain D7 microorganism from pest icidal applications do not exceed EPA’s level of concern, particularly in light of available data that demonstrate Pseudomonas fluorescens strain D7 is not toxic (acute dermal toxicity and acute pulmonary

toxicity / pathogenicity), is non - irritating (primary dermal irritation), and is not pathogenic when used as labeled in accordance with good agricultural practices (acute pulmonary toxicity /pathogenicit y, and acute injection toxicity /pathogenicity).
**I V**  **. Cumulative E** 

**ffec ts**  **f rom**  **S u**  **bsta n**  **ce**

**s w**  **i t**  **h a**  **C o**  **m m**  **on M** 

**ec h**  **a n**  **i s** **m of Toxi** **c ity**  Section 408(b)(2)(D)(v) of FFDCA requires that, when considering whether to establish, modify , or revoke a tolerance exemption, the EPA consider “available information concerning the cumulative effects of [a particular pesticide’s] . . . residues and other substances that have a common mechanism of toxicity .” The EPA has not found Pseudomonas fluorescens strain D7 to share a common mechanism of toxicity with other substances
. Pseudomonas fluorescens strain D7 does not appear to be toxic to humans via dietary , dermal and pulmonary

exposure. For the purposes of the tolerance action, therefore, the EPA has assumed that Pseudomonas fluorescens strain D7 does not have a common mechanism of toxicity with other substances. Thus, section 408(b)(2)(D)(v) of the FFDC A does not apply . For information regarding the EPA’s efforts to determine which chemicals have a common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see the EPA’s website at http://www.epa.gov/pesticides/cumulative
.

.6 **V . D**  **e t**  **e r**  **m i**  **n ation**  **of S** 

**a f**  **e ty**  **f or t**  **h e**  **U n**  **it e**  **d S**  **tat e** **s Pop u**  **latio n**  **, I** 

**n f**  **a n**  **ts a**  **n d**  **Ch ildr** **e n**  In considering the establishment of a tolerance or tolerance exemption for a pesticide chemical residue, FFDCA section 408 (b) (2) (C) provides that the EPA shall assess the available information about consumption patterns among infants and children, special susceptibility of infants and children to pesticide chemical residues, and the cumulative effects on infants and children of the residues and other substances with a common mechanism of toxicity . In addition, FFDCA section 408(b) (2) (C) provides that the EPA shall apply

an additional tenfold (10X) margin of exposure (safet y) for infants and children in the case of threshold effects to account for prenatal and postnatal toxicity and the completeness of the database on toxicity and exposure unless the EPA determines that a different margin of exposure (safety) will be safe for infants and children. This additional margin of exposure (safet y) is commonly referred to as the Food Quality Protection Act Safet y Factor. In appl yi ng this provision, the EPA either retains the default value of 10X or uses a different additional safet y factor when reliable data available to the EPA support the choice of a different factor. Based on the acute toxicity and pathogenicit y data/information discussed in section I I above (and Ref. 2), the EPA concludes that there are no threshold effects of concern to infants, children, or adults when Pseudomonas fluorescens strain D7 is used as labeled in accordance with good agricultural practices. As a result, the EPA concludes that no additional margin of exposure (safety) is necessary to protect infants and children and that not adding an y additional margin of exposure (safety) will be safe for infants and children. Moreover, based on the same data/information and EPA anal ys is as presented directl y above, the Agency is able to conclude that there is a reasonable certainty that no harm will result to the United States population, including infants and children, from aggregate exposure to the residues of Pseudomonas fluorescens strain D7 when it is u sed

— as labeled and in accordance with good agricultural practices

— as an herbicide . Such exposure includes all anticipated dietary exposures and all other exposures for which there is reliable information. The EPA has arrived at this conclusion because, con sidered collectively , the data and information available on Pseudomonas fluorescens strain D7 do not demonstrate toxic or pathogenic potential to mammals, including infants and children.

. **V I**  **. Conclusions** The E P A c on c lud e s th at th er e is a r ea so n a ble c ert a int y th at no h ar

m will re s ult to the U. S . popul atio n , in c luding in fants and c hildre n, fr om a ggr e g ate e x posur e to re sidu e s of Pseudomonas fluorescens strain D7
. Th eref o re , an e x e mption fr om the re qui r e m e nt of a tol eran c e is e st a blish e d f or re sidu e s o f Pseudomonas fluorescens strain D7 in or on a ll food c ommoditi e s when applied or used in accordance with label directions and good agricultural practices
. **V II**  **. References**
1. Palleroni, N. J. 2005. Pseudomonas. Pp. 323

– 379. In: Bergey ’s Manual of Sy stematic Bacteriology , Vol. 2. D. J. Brenner, N. R. Krieg, and J. T. Staley (Eds.) Springer, New York, New York 2. Biopesticides Registration Action Document (BRAD) for Pseudomonas fluorescens strain D77

3. U
. S
. EPA. 2014a. Memorandum from I. Barsoum (OPP/BPPD) to S. Cerrelli, Re: Review of Acute Toxicity /Pathogenicit y study for section 3 registration of the TGAI, Fluorescens Technical, and the EP, D7, containing the active ingredient Pseudomonas fluorescens str ain D7. Dated April 15, 2014. 4. U
. S
. EPA. 2014b. Memorandum from I. Barsoum (OPP/BPPD) to S. Cerrelli, Re: Review of Acute Toxicity /Pathogenicit y study for section 3 registration of the TGAI, Fluorescens Technical, and the EP, D7, containing the active i ngredient Pseudomonas fluorescens strain D7. Dated April 22 , 2014. 5. Centers for Disease Control and Prevention. 2009. Drinking Water

- Water Treatment. Available from htt p://www.cdc.gov/healthywater/drinking/public/water_treatment.html
. 6. U.S. EPA. 2004. Primer for Municipal Wastewater Treatment S ys tems. EPA 832
- R
- 04
- 001. Available from http://www.epa.gov/npdes/pubs/primer.pdf 7. DeFelice K, Wollenhaupt N, Buchholz D. 1993. Aquifers and Soil Filter Effect. Available from http://extension.missouri.edu/p/WQ24
.