Michael Suplee, Ph.D.Michael Suplee, Ph.D.

MT Department of Environmental QualityMT Department of Environmental Quality

Water Quality Standards SectionWater Quality Standards Section

March 1, 2007March 1, 2007

Numeric Nutrient Standards for Numeric Nutrient Standards for Surface Waters of MontanaSurface Waters of Montana

Why Numeric Nutrient Standards for Why Numeric Nutrient Standards for Surface Waters?Surface Waters?

• Nationally, nutrient enrichment ranks among the top Nationally, nutrient enrichment ranks among the top causes of water resource impairment causes of water resource impairment

• MT MT narrative narrative standard: “state waters must be free from standard: “state waters must be free from substances….that will: (e) create conditions which produce substances….that will: (e) create conditions which produce undesirable aquatic life” (ARM 17.30.637)undesirable aquatic life” (ARM 17.30.637)

• Can affect DO. DO must not be reduced below class Can affect DO. DO must not be reduced below class specific criteria (e.g., ARM 17.30.623 [b])specific criteria (e.g., ARM 17.30.623 [b])

• State-of-the-science is such that developing numeric State-of-the-science is such that developing numeric criteria appears feasiblecriteria appears feasible

Clark Fork River above Clark Fork River above The Little Blackfoot R.,The Little Blackfoot R.,

July 2004July 2004

Yellowstone River @ Miles City,Yellowstone River @ Miles City,August 2006August 2006

EPA National Strategy for Numeric EPA National Strategy for Numeric Nutrient StandardsNutrient Standards

““EPA expects all States and Tribes to EPA expects all States and Tribes to adopt and implement numerical adopt and implement numerical nutrient criteria into their water nutrient criteria into their water

quality standards by December 31, quality standards by December 31, 2003.”2003.”

Federal Register, June 25, 1998Federal Register, June 25, 1998

EPA National Strategy for Numeric EPA National Strategy for Numeric Nutrient StandardsNutrient Standards

•November 2001: EPA softened its 2003 November 2001: EPA softened its 2003 adoption expectationsadoption expectations

•States develop plans/schedule for nutrient States develop plans/schedule for nutrient standards adoptionstandards adoption

•States conduct scientific studies at the States conduct scientific studies at the State/regional levelState/regional level

•About half of States planning to adopt About half of States planning to adopt numeric nutrient criteria in 2008numeric nutrient criteria in 2008

Select Variables N, P etc.

Decide upon acceptable algae levels Uses Waterbody type

Build Database Available, multiagency data Scientific research studies Collect new data

Analyze Data

Develop Criteria Ranges

Implement Nutrient Criteria

Monitor and Reassess Criteria

Presented to Presented to WPCAC, WPCAC,

April 2001April 2001

Setting Up a Geospatial FrameworkSetting Up a Geospatial Framework

• Nutrient concentrations vary naturally — geology, Nutrient concentrations vary naturally — geology, soils, climate, vegetationsoils, climate, vegetation

• DEQ needed a practical, easy-to-apply geospatial DEQ needed a practical, easy-to-apply geospatial framework that explained a good proportion of framework that explained a good proportion of nutrient-concentration variability in surface watersnutrient-concentration variability in surface waters– Ecoregions (developed by Jim Omernik)Ecoregions (developed by Jim Omernik)– LithologyLithology– Strahler Stream OrderStrahler Stream Order

Level III Ecoregions of MT (Woods et al. 2002)Level III Ecoregions of MT (Woods et al. 2002)

USGS Geology Map of Montana (1955USGS Geology Map of Montana (1955))

Strahler Stream OrderStrahler Stream Order

1111

11 11

22

22 11

33

11 1111

11

22

22

33

44

11

ConclusionsConclusions

• As a geospatial framework, level III & IV As a geospatial framework, level III & IV ecoregions outperformed lithology and stream ecoregions outperformed lithology and stream order, in terms of statistical significance of order, in terms of statistical significance of measures of variationmeasures of variation

• Ecoregions explained a sufficient degree of Ecoregions explained a sufficient degree of nutrient variability that they may be used as a nutrient variability that they may be used as a basis to establish criteria in Montanabasis to establish criteria in Montana

Determining CriteriaDetermining Criteria

• Criteria based on concentrations where beneficial-Criteria based on concentrations where beneficial-use impacts begin to occur use impacts begin to occur – RecreationRecreation– Fisheries Fisheries

• Impact thresholds are determined using:Impact thresholds are determined using:– stressor-response studies (e.g., TN vs. DO correlation) stressor-response studies (e.g., TN vs. DO correlation) – Reference stream data (sites with minimal impacts) Reference stream data (sites with minimal impacts) – nuisance algae public opinion surveysnuisance algae public opinion surveys

Study of prairie streams in Study of prairie streams in Northeastern Montana, 2001-2004Northeastern Montana, 2001-2004

2.002.102.202.302.402.502.602.702.802.903.003.103.20

0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50

Mean TN Concentration (mg/ L)

Dia

tom

OR

I

5 mg/L

4 mg/L

Diatom

Inferrred DO

6 mg/L

Yellow Dots: ReferenceBlue Dots: Non-reference

Significant change point

Desirable?Desirable?

Desirable?Desirable?

Bottom Line on the Draft CriteriaBottom Line on the Draft Criteria

• Nutrient concentrations that protect uses are lowNutrient concentrations that protect uses are low

Typical concentrationsTypical concentrations::– Total P: 0.05 mg/LTotal P: 0.05 mg/L– Total N: 0.3 mg/LTotal N: 0.3 mg/L

• Difficult for current waste-water technologies to meet Difficult for current waste-water technologies to meet criteriacriteria– Low-flow streams, limited dilutionLow-flow streams, limited dilution

Economic ConsiderationsEconomic Considerations• Federal regs not intended to result in WQ standards Federal regs not intended to result in WQ standards

so stringent that compliance would cause severe so stringent that compliance would cause severe economic impacts on a communityeconomic impacts on a community

• Federal law requires economic impact to be Federal law requires economic impact to be “substantial” and “widespread”“substantial” and “widespread”– For treatment beyond technology-based regulationsFor treatment beyond technology-based regulations– CWA Options: remove use, create use subcategories, do CWA Options: remove use, create use subcategories, do

a variancea variance

• 75-5-301 (2) (a), § MCA: 75-5-301 (2) (a), § MCA: formulate and adopt formulate and adopt standards of water quality, giving consideration to standards of water quality, giving consideration to the economics of waste treatment and preventionthe economics of waste treatment and prevention..

Economic Considerations-ExampleEconomic Considerations-Example

• Philipsburg, MontanaPhilipsburg, Montana– 930 people930 people– Aging lagoon-based treatment system, can’t Aging lagoon-based treatment system, can’t

accommodate more growthaccommodate more growth– periodically out of complianceperiodically out of compliance

• New mechanical plant (BNR) and clean-up of New mechanical plant (BNR) and clean-up of lagoons: $6,131,987.00lagoons: $6,131,987.00

• Per-household sewer rates would rise from Per-household sewer rates would rise from ~$15/month to ~$15/month to >> $70/month $70/month

Economic Considerations-ScreeningEconomic Considerations-Screening

Step 1Step 1: EPA recommends the “Municipal Preliminary Screener” ; : EPA recommends the “Municipal Preliminary Screener” ; meets smeets substantialubstantial test test

Municipal Preliminary Screener (MPS)Municipal Preliminary Screener (MPS) = Mean total pollution = Mean total pollution

control cost per household / median household incomecontrol cost per household / median household income

• MPS < 1% : Cost bearable, no further analysisMPS < 1% : Cost bearable, no further analysis

• MPS 1-2%: Midrange impacts; further analysis possibleMPS 1-2%: Midrange impacts; further analysis possible

• MPS > 2%: Unreasonable cost expected for many householdsMPS > 2%: Unreasonable cost expected for many households

• EPA Break points are recommendations; alternatives existEPA Break points are recommendations; alternatives exist

Step Step 22: Carry out : Carry out widespreadwidespread tests (methodology not explicit) tests (methodology not explicit)

Economic ConsiderationsEconomic Considerations

• DEQ wants to set up committee to evaluate & DEQ wants to set up committee to evaluate & determine “how expensive is too expensive?”determine “how expensive is too expensive?”– WQ regulatorsWQ regulators– Economist(s)Economist(s)– Special interest groupsSpecial interest groups– Affected partiesAffected parties

• DEQ will later present this committee’s DEQ will later present this committee’s conclusions to WPCACconclusions to WPCAC

Wrap-UpWrap-Up• EPA continues to expect States to adopt numeric EPA continues to expect States to adopt numeric

nutrient criteria into their water quality standardsnutrient criteria into their water quality standards

• DEQ continues to carry out studies to determine DEQ continues to carry out studies to determine impact thresholds of nutrients on beneficial water impact thresholds of nutrients on beneficial water uses (recreation, fisheries, aquatic life)uses (recreation, fisheries, aquatic life)

• Draft criteria concentrations low; cost of treatment Draft criteria concentrations low; cost of treatment could be highcould be high

• DEQ is planning to assemble a committee to evaluate DEQ is planning to assemble a committee to evaluate “how expensive is too expensive?”“how expensive is too expensive?”