Overview of the Development and Implementation of

Montana’s Numeric Nutrient Standards

Michael Suplee, Ph.D.Water Quality Standards Section

MT Dept. of Environmental Quality

March 5th, 2015MMIA/MSU Mayor & City Manager Forum

Helena, MT

Overview of Nutrient Standards Development in MT

• 1980s: Phosphorus detergent bans in Flathead, Clark Fork basins• 1990s: Clark Fork River criteria derived; VNRP

• 2001: DEQ begins criteria development for all surface waters

• 2002: Clark Fork River criteria adopted as standards by BER

• 2003-2008: Statewide criteria for wadeable streams generally identified. DEQ develops a system for establishing zones for different criteria. Large river criteria development started.

• 2009: SB 95 adopted, allows variances from nutrient standards on a case-by-case; Nutrient Work Group (NWG) created

• 2011: NWG input → SB 367; bill adopted, provided general variances

• 2011-present: DEQ & NWG address implementation; adoption 2014

Nuisance algal growth, rivers &

streams

120 mg Chla/m2

40 mg Chla/m2

300 mg Chla/m2

Attached algae growth commonly quantified as chlorophyll a per square meter of stream bottom

0 50 100 150 200 250 300 350 400 450 500Benthic algae level (mg Chla/m2)

Known/likely effects on wadeable-streams at different algae levels (western MT)

Recreation acceptable Recreation unacceptable

Increasing salmonid growth & survival

Salmonid growth & Survival high

Salmonid growth & Survival possibly reduced

Salmonid growth & survival very likely impaired

No DO problems DO problems very likelyDO problems sporadic

Stonefly, mayfly caddis-fly dominant

Shift in biomass & community structure

Midges, worms, mollusks, scuds dominant

?

Eastern Montana Wadeable Streams Different assessment methods (dissolved oxygen, biometrics) from western Montana

DEQ carrying out a 4-year study to better understand DO, nutrient relationships in region

Deriving Numeric Nutrient Criteria: Wadeable Streams

3 Major Pieces:

1) Identify geographic zones for specific criteria

2) Understand cause-effect relationships between nutrients and beneficial uses • Requires determining “harm to use”• Different expectations for different regions of the

state

3) Characterize water quality of reference sites• Data from 2 and 3 considered together

Deriving Numeric Nutrient Criteria for Wadeable Streams: the Geospatial Frame

• Ecoregions worked better than surface geology and stream order

– Significantly explained nutrient concentration variation (typically 60-78% of variation in reference data)

– Practical to apply

Mountainous Prairie Transitional

DEQ’s Nutrient Criteria Derivation Process

Regional Dose-response studies

CRITERION

Comparison to Regional

Reference-site Data

N:P Resource Ratio(Redfield Ratio)

Example Dose-Response Relationship: Clark Fork River, 1998-2009

Stream Reference Sites n=185

Numeric Nutrient Standard

Ecoregion (level III or IV) and Number Ecoregion Level Period When Criteria

Apply

Total Phosphorus

(µg/L)Total Nitrogen

(µg/L)

Northern Rockies (15) III July 1 to September 30 25 275

Canadian Rockies (41) III July 1 to September 30 25 325

Idaho Batholith (16) III July 1 to September 30 25 275

Middle Rockies (17) III July 1 to September 30 30 300

Absaroka-Gallatin Volcanic Mountains (17i) IV July 1 to September 30 105 250

Northwestern Glaciated Plains (42) III June 16 to September 30 110 1300

Sweetgrass Upland (42l), Milk River Pothole Upland (42n), Rocky Mountain Front Foothill Potholes (42q), and Foothill Grassland (42r)

IV July 1 to September 30 80 560

Northwestern Great Plains (43) and Wyoming Basin (18) III July 1 to September 30 150 1300

River Breaks (43c) IV Narrative only Narrative only Narrative only

Non-calcareous Foothill Grassland (43s), Shields-Smith Valleys (43t), Limy Foothill Grassland (43u),

Pryor-Bighorn Foothills (43v), and Unglaciated Montana High Plains (43o)*

IV July 1 to September 30 33 440

Large Rivers:

Yellowstone River (Bighorn River confluence to Powder River confluence) n/a August 1 -October 31 55 655

Yellowstone River (Powder River confluence to stateline) n/a August 1 -October 31 95 815

Selected MT Numeric Nutrient Standards: wadeable streams, large rivers

– Traverse several ecoregions– No reference sites for comparison– Deeper/faster than streams; changes light regime and other factors

Using steady-state QUAL2K model

– Vary nutrient inputs, observe effects on water quality standards • Dissolved oxygen concentration, pH, total dissolved gas levels• Nuisance benthic algae levels• Total organic carbon concentration (drinking water use)

Large Rivers

Most Montana Streams already Meet the Criteria

Based on probabilistic stream survey:

• About 70-80% of stream miles statewide currently meet the TP criteria

• About 85-90% of stream miles statewide currently meet the TN criteria

Implementation

Standard

Standard

Variances from Numeric Nutrient Standards: Economic Considerations

• Options available for communities to receive temporary relief from the standards based on:– Inability to pay for treatment/economics– Limits of technology

• General Variances• Individual Variances

Senate bills 95 (2009 Legislature) and 367 (2011 Legislature) (now §75-5-313, MCA)

• DEQ given authority to grant variances from nutrient criteria• Based on economic harm that would have resulted from immediate

implementation of the standards– Variances up to 20 years, subject to 3-year reviews

– General Variance: Can be requested if criteria can’t be met, but these can:– > 1 MGD: 1 mg TP/L, 10 mg TN/L– < 1 MGD: 2 mg TP/L, 15 mg TN/L– Lagoons: Maintain current performance

– Individual Variance: Permittee may apply for these if meeting the general variance is difficult, or if treating beyond gen. levels does not make sense. Case-by-case analysis.

Must be adopted in Dept. rule by 5/31/2016 (DONE)

Nutrient Trading

• 2013: Board of Environmental Review adopted rules allowing dischargers to use nutrient trading to help comply with numeric nutrient standards and variances– Found in Department Circular DEQ-13

OVERALL: Law allows Montana to implement numeric nutrient criteria in a staged manner over ~ 20 years, allowing critical time to better address all sources

of nutrient pollution (point and nonpoint) and for treatment technology

to improve/come down in cost

Today 20 years

Efflue

nt N

utrie

nt C

once

ntra

tion

TIME

Numeric Nutrient Standard

Step reductions in effluent nutrientconc. from a facility (> 1 MGD, <1 MGD)under the variance

15 yrs10 yrs5 yrs

General Variance Concentrations in statute

?

Nutrient Reduction Steps (DEQ Guidance Document)

Reduction Steps in DEQ Guidance

• 1. Facilities > 1 MGD:

• A. 1st general variance: 10 mg TN/L, 1.0 mg TP/L -per statute• B. Next permit (+5 years): 8 mg TN/L, 0.8 mg TP/L• C. Next permit: 8 mg TN/L, 0.5 mg TP/L• D. Next permit: Under Development

• 2. Facilities < 1 MGD:

• A. 1st general variance) 15 mg TN/L, 2.0 mg TP/L -per statute• B. Next permit (+5 years): 12 mg TN/L, 2.0 mg TP/L• C. Next permit: 10 mg TN/L, 1.0 mg TP/L• D. Next permit: 8 mg TN/L, 0.8 mg TP/L

• 3. Lagoons not designed to actively remove nutrients:

• A. 1st general variance: Maintain current lagoon performance, start nutrient monitoring -per statute

• B. Next permit (+5 years): Implement BMPs identified during optimization study

Lagoon Optimization Study

• MT DEQ is compiling innovative, low-cost approaches to reduce ammonia and total nutrients from facultative lagoon discharges (2014-15)

• Intend to carry out trial tests of methods with a group of cooperating communities, starting 2016

Where to Find Things

• Standards, Circulars DEQ-12A & B, Guidance Document:

→DEQ Homepage → water icon →WQ Protection →Standards & Classification

• Circular DEQ-13 (Trading):→DEQ Homepage, type “Circulars” in search box →Water Quality Circulars

• Nutrient Work Group:→ DEQ Homepage→ Advisory Councils →Nutrient Work Group

Overview• The nutrient criteria are scientifically defensible, appropriate for

different regions and waterbody types– Provide clarity on the water quality endpoints– Ongoing work will lead to other large-river nutrient standards, refinement

of wadeable stream standards

• Statute allows the numeric nutrient standards to be met over ~20 years via variances– If more time needed, additional law-making likely needed

• Rule adoption for numeric nutrient standards and variances was finalized summer 2014– Numeric nutrient standards and variance procedures became effective

August 2014

Thank You

Contact Information:• (406) 444-5320 — Eric Urban (Water Quality Planning Bureau Chief)• (406) 444-0831 — Michael Suplee (Water Quality Standards Section)

• EUrban@mt.gov• msuplee@mt.gov