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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)