Considerations for NPDES Gene

Permit for Aquatic Pesticide

• Focus: Aquatic Weed and Algae Control• NOI

– Who needs to file?

– Treated Acreage Threshold?

• Case Studies

– NOIs in practice

– Treatment Scale and Product Choice v. Goal of Eliminating 

• Effl t uen Li it m s

– Quantitative?

• Monitoring

– Ch ll a enges of confi i rm ng proper di h sc arge / lbl a e complian

analytical sampling
NOI Considerations

• EPA Approach?

– 160 water acres in calendar year– Questions:

• Treated acres or water body?

• Multiple treatments treatments of same acreage? acreage?

– NOI ‘Operator’

• decision decision to treat and/or control control of compliance compliance 
NOI Considerations

• Challenges

– Permitees will work to stay under NOI thre

and significant discharge activity might no

captured via NOI system

– Examples:

• Keep treatments less under 160 acres in a give

body

– Lake Association is the ‘operator’...subcontracts ap– Can applicator avoid adding 160 acres to aggregate 

– Encourages less reliance on certified applicators w

exceed thresholds (less qualified applicators or do‐
NOI Considerations

• Challenges

– Permitees will seek to use spot treatment solutions that e

of older chemistry with higher use rates and less favorable 

– Maximum Use Rates v. MCL

• New (since 1986)(in‐water)

– Imazamox 0.500 ppm MCL = Not Estab...Tol

– Penoxsulam 0.150 ppm MCL = Not Estab...DW

– Fluridone 0.150 ppm MCL = Not Estab...HA

– Triclopyr 2.500 ppm MCL = Not Estab...0.4 

• Old

– Diquat 0.370 ppm MCL = 0.020 ppm– Endothall 5.000 ppm MCL = 0.100 ppm– 2,4‐D 4.000 ppm MCL = 0.070 ppm– Copper 1.000 ppm MCL = 1.300 ppm
NOI – Case Study 1 (LAKES

5 lakes – avg 100 surface acres each (10 ft mea

25% avg cover of invasive submersed weeds (5 

PERMITEE GOAL: Avoid NPDES NOI Submissio

25

•ACTION: 25 acres of small‐scale treatment pe

@ 100 lbs/A of 19% 2,4‐D ester granule (

= 2,500 lbs of formulated herbicide or 47

25 acres

2,375 lbs of herbicide discharged for 5 la

NO NOI NEEDED (only 125 total acres tre

PERMITEE GOAL: Use BAT and Reduce Enviro

100 total acres

•ACTION: 100 acres of whole‐lake treatment w

@ 10 ppb total 4 lb ai / gal liquid = 6.8 ga= 27.2 lbs ai per 100 acre lake

136 lbs of herbicide discharged for 5 lak

NOI NEEDED (all 500 total acres treated)

NOI THRESHOLD THRESHOLD WOULD DISCO

DISCO

17‐fold REDUCTION IN DISCH
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NOI – Case Study 2 (POND

40 5‐A Ponds – 5 ft mean depth

20% avg cover of invasive submersed weeds

PERMITEE GOAL: Avoid NPDES NOI Submiss

•ACTION: Treat 1 acre per pond with contact 

@ 2 gal/A of 2 lb ai/gal diquat = 4 lbs ai 

160 lbs of herbicide discharged for 40 

Three Repeat Applications = 480 total 

NO NOI NEEDED (only 120 total acres t

PERMITEE GOAL: Use BAT and Reduce Env L

5 acres

•ACTION: 5 acres of whole‐pond treatment w

@ 45 ppb total 5% pellet = 60 lbs pellet

= 3 lbs ai per pond for season

120 lbs of herbicide discharged for 40 

NOI NEEDED (all 200 total acres treate

NOI THRESHOLD THRESHOLD WOULD DISCO

DISCODISCO

4‐fold REDUCTION IN DISCHA
Potential Permit Model

Potential Threshold‐Based ComplianceB) All waterbodies 10 to 100 acres file NOI short form and comply with the following permit prA) All waterbodies < 10 acres, automatically covered by General NPDES permit. Retain spray re

map and watersample analysis data (a.i.) for 3 yrs.

Potential Threshold‐Based ComplianceB) All waterbodies 10 to 100 acres file NOI short form and comply with the following permit prA) All waterbodies < 10 acres, automatically covered by General NPDES permit. Retain spray re

map and watersample analysis data (a.i.) for 3 yrs.

B) All waterbodies 10 to 100 acres, file NOI short form and comply with the following permit pr

C) All waterbodies > 100 acres submit NOI long form and then comply with following permit pr

Waterbody Size (acres)

Permit Provision < 10 10 to 100 > 100

B) All waterbodies 10 to 100 acres, file NOI short form and comply with the following permit pr

C) All waterbodies > 100 acres submit NOI long form and then comply with following permit pr

Waterbody Size (acres)

Permit Provision Provision < 10 10 to 100 > 100

Notice of Intent ‐ Short xNotice of Intent ‐ Long xActive Ingredient Monitoring x x xBMP x x

Permit Provision < 10 10 to 100 > 100

Notice of Intent ‐ Short xNotice of Intent ‐ Long xActive Ingredient Monitoring x x xBMP x xBAT x x

PDMP (Pesticide Discharge Management Plan) x

Monitoring and Surveillance

(quantitative) xRecord Keeping (at a minimum spray report,

BAT x x

PDMP (Pesticide Discharge Management Plan) x

Monitoring and Surveillance

(quantitative) xRecord Keeping (at a minimum spray report,

map, a.i. pre/post data) xxx

Annual Report to EPA or State x

map, a.i. pre/post data) xxx

Annual Report to EPA or State x
Monitoring

• Analytical confirmation confirmation of discharge discharge see

essential to:

– Classify discharge as excess/waste per cou

language

– Attribute an adverse incident to pesticide

di h sc arge versus some other envi 

ronment

• Adverse incident – means an incident which you have obs

inspection or of which you otherwise become aware, in w

• (1) A person or non‐target organism may have been expo

pesticide residue, and

• (2) The person or non‐target organism suffered a toxic or a

effect....
Monitoring

• Challenges of Requiring Requiring Analytical Analytical Mon

Mon

– Impractical / Impossible to implement ana

monitoring monitoring for every aspect of aquatic aquatic trea

trea

• Expense, lack of resources, complexities of use 

sampling design

– Lack of monitoring greatly increases poten

legal action

• Adverse incident...must have been treatment 

regulatory groups should have provided betteoversight
Monitoring

• CA State NPDES Permit (precedent)

– 10% of all sites– Background, Event, Post‐Event Monitoring– Provides Provides some defense defense that label was followed followed

• Why will EPA not implement requirements sim

CA?

• What approaches will states tak ?e

– CA or more‐‐‐‐‐‐‐‐Nothing

• Legal challenges challenges with having different different system

system

– Most water is interstate in nature...different

interpretations
Monitoring

• Possible Approach?

– Require representative analytical monitoring for all a

confirm label compliance

• Multiple uses for CWA and FIFRA regulation• Did you achieve b t u not exceed t t arge dose

– Under Target: potential waste because didn’t maximize dose a

control

– Over Target: excess or potential FIFRA violation

• R t ti 10% i il Representative...10%...similar to CA mod l e• Pre‐Treatment

– Confirm no background signal

• Post‐Treatment

– Immediately post treatment (liquid)

– Peak of release for dry formulations

» 24 hours after treatment – 3 weeks after treatment

• Require Require for other FIFRA‐regulated regulated water uses
Misc Topics

• General BMP

– Citations of bathymetry source should be req

all NOI treatments.

– Updated Updated bathymetry bathymetry (last 10 years) should be

required for all treatments over 100 acres and

recommended for all.

– Flow readings readings ann all u y for con e ances veyances

• E.g., WA irrigation system permit

• Biologicals

– How might they be approached differently vs

chemical products in permit?