Overview of Numeric Nutrient Criteria Development and Implementation in Montana Michael Suplee, PhD Water Quality Standards Section Montana Department of Environmental Quality Presented to the Water Pollution Control Advisory Council February 17, 2012
Presentation Outline Brief timeline of criteria development in Montana Brief timeline of criteria development in Montana Why numeric nutrient criteria? Why numeric nutrient criteria? Criteria derivation: methods overview Criteria derivation: methods overview – Wadeable streams, Large rivers, Lakes/reservoirs Trends on the Clark Fork River Trends on the Clark Fork River Implementation: Meeting the standards over time Implementation: Meeting the standards over time – Senate bills 95 and 367 Nutrient Work Group Nutrient Work Group Draft Circular DEQ-12 and new rules Draft Circular DEQ-12 and new rules USEPA acceptance of Montana’s approach USEPA acceptance of Montana’s approach Timeline: adoption of statewide nutrient criteria Timeline: adoption of statewide nutrient criteria
Brief and Incomplete Overview of Nutrient Criteria Development in Montana 1990s: Clark Fork River criteria derived; VNRP 1990s: Clark Fork River criteria derived; VNRP 2001: DEQ begins criteria development for all waters 2001: DEQ begins criteria development for all waters 2002: Clark Fork River criteria adopted as standards 2002: Clark Fork River criteria adopted as standards : Statewide criteria for wadeable streams generally identified, and a system for establishing different criteria zones developed by DEQ : Statewide criteria for wadeable streams generally identified, and a system for establishing different criteria zones developed by DEQ 2009: SB 95 adopted, allows variances from nutrient standards on a case-by-case. NWG created 2009: SB 95 adopted, allows variances from nutrient standards on a case-by-case. NWG created 2011: SB 367 adopted, refining variance process, allows for general variances 2011: SB 367 adopted, refining variance process, allows for general variances
Why Numeric Nutrient Criteria? Existing standards are narrative (“no nuisance aquatic life”, etc.) Existing standards are narrative (“no nuisance aquatic life”, etc.) – Intent fairly clear, application inconsistent Nutrient (i.e., nitrogen and phosphorus) over- enrichment directly and indirectly impacts other, existing numeric WQ standards: Nutrient (i.e., nitrogen and phosphorus) over- enrichment directly and indirectly impacts other, existing numeric WQ standards: – Dissolved oxygen, pH, nuisance algal growth, etc. Better to address root cause via nutrient standards Allows for more consistent permitting and TMDL application Allows for more consistent permitting and TMDL application
Clark Fork River Nuisance algal growth, rivers & streams
Benthic algae level (mg Chla/m 2 ) Actual/likely affects on stream uses at varying algae levels (wadeable streams) 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 problemsDO problems very likelyPossible DO problems Stonefly, mayfly caddis- fly dominant Shift in biomass & community structure structure Midges, worms, mollusks, scuds dominant ?
Nutrient Criteria Derivation: Wadeable Streams 3 major parts: 1)Identification of appropriate geographic zones in which specific nutrient criteria (total P, total N) would apply 2)Understanding of cause-effect (i.e., stressor-response) relationships between nutrients and beneficial uses Requires determining “harm to use” Requires determining “harm to use” Different expectations for different regions of the state Different expectations for different regions of the state 3)Water quality data from reference sites Data from 2 and 3 above can (and should) be considered together
Montana Ecoregions (level III, IV) MountainousPrairie
Dose-response studies carried out in a level III ecoregion occurring in MT (except Mebane [2010])
Reference Stream Sites Nutrient concentration data from reference streams — which support all their beneficial uses and have minimal impacts — are compiled for each ecoregion (III, and IV if possible) Western MT reference stream site Eastern MT prairie-stream reference site
Comparing reference data and dose- response study results Frequency Regional Reference-stream Nutrient Concentrations 50 th percentile (median) 75 th percentile 25 th Range of nutrient concentrations across which impacts to beneficial stream uses are likely to begin to occur 99 th percentile
Coming Soon: Ecoregion-by- ecoregion discussion of how criteria were established (addendum to Suplee et al. 2008)
– No comparable reference available, as for wadeables – Large rivers much deeper/faster than wadeable streams; changes light regime and other factors Solution: Use mechanistic water-quality models – Can vary nutrient inputs in model and observe effects on other water quality parameters/standards, like DO DO Nuisance benthic algae growth Nuisance benthic algae growth pH pH Total organic carbon (TOC) Total organic carbon (TOC) Total dissolved gas (TDG) Total dissolved gas (TDG) Nutrient Criteria Derivation: Large Rivers
Lower Yellowstone River – Used QUAL2K model to derive criteria Steady state Steady state Simulates benthic algae Simulates benthic algae – Study reach km or 145 miles – Low flows near 100 m 3 /sec (3,280 cfs) ; free flowing
For wadeable streams/large rivers, criteria apply seasonally (summer and fall) only, when algal growth is peak and ensuing water quality impacts are maximal Table 1. Montana Draft Nutrient Criteria for some ecoregions and the lower Yellowstone River Level III Ecoregion Period When Criteria Apply Parameter Total P (mg/L)Total N (mg/L) Related Assessment Information Northern RockiesJuly 1 -Sept mg Chl a/m 2 (36 g AFDW/m 2 ) Canadian RockiesJuly 1 -Sept mg Chl a/m 2 (36 g AFDW/m 2 ) Middle RockiesJuly 1 -Sept mg Chl a/m 2 (36 g AFDW/m 2 ) Idaho BatholithJuly 1 -Sept mg Chl a/m 2 (36 g AFDW/m 2 ) Northwestern Glaciated PlainsJune 16-Sept n/a Northwestern Great Plains, Wyoming BasinJuly 1 -Sept n/a Yellowstone River (Bighorn R. confluence to Powder R. confluence) Aug 1 -Oct Nutrient concentrations based on limiting pH impacts Yellowstone River (Powder R. confluence to stateline) Aug 1 -Oct Nutrient concentrations based on limiting nuisance algal growth
Nutrient impacts to lakes Loss of water clarity; reduction of recreation and aesthetic quality and property value Loss of water clarity; reduction of recreation and aesthetic quality and property value Increased frequency of noxious algae blooms Increased frequency of noxious algae blooms Changes in fish species composition Changes in fish species composition Loss of macrophytes, replaced by dense phytoplankton Loss of macrophytes, replaced by dense phytoplankton Taste and odor problems (drinking water source) Taste and odor problems (drinking water source)
Nutrient Criteria Derivation: Lakes and Reservoirs Under development. Data collection in Montana lakes was completed between Under development. Data collection in Montana lakes was completed between Reservoirs pending. Plan to use a modeling approach Reservoirs pending. Plan to use a modeling approach – Canyon Ferry Reservoir first project; No lake or reservoir criteria will be recommended for rule making this year except perhaps Flathead Lake No lake or reservoir criteria will be recommended for rule making this year except perhaps Flathead Lake
How Goes the Clark Fork River? 1998: Stakeholders develop voluntary nutrient reduction plan (VNRP) and implementation process. 1998: Stakeholders develop voluntary nutrient reduction plan (VNRP) and implementation process. – Basin-wide phosphorus ban in place since 1989 – Criteria adopted as rules by state in : Major nutrient reduction efforts in place (e.g., BNR plant in Missoula) 2004: Major nutrient reduction efforts in place (e.g., BNR plant in Missoula) Site 18, Clark Fork River below Missoula,
Implementation: Statewide approach to meet the standards over time
Implementation: Economic Considerations Option are available for communities to receive temporary relief from the requirements based on: Option are available for communities to receive temporary relief from the requirements based on: – Ability to pay for treatment (affordability) – Availability of treatment technology (limits of technology) These options apply only to wastewater treatment beyond the federally mandated technology-based regulations (i.e., National Secondary Standards) These options apply only to wastewater treatment beyond the federally mandated technology-based regulations (i.e., National Secondary Standards)
Senate bills 95 (2009 Legislature) and 367 (2011 Legislature) (now § , MCA) Give DEQ authority to grant variances from nutrient criteria, based on substantial & widespread economic harm that would result from immediate implementation of the standards Give DEQ authority to grant variances from nutrient criteria, based on substantial & widespread economic harm that would result from immediate implementation of the standards – Variances up to 20 years, subject to 3-year reviews – General Variance: If permittee can’t meet criteria, but can treat effluent to statute-defined levels, they will receive a gen. variance, by groups: – > 1 MGD: 1 mg TP/L, 10 mg TN/L – < 1 MGD: 2 mg TP/L, 15 mg TP/L – Lagoons: Maintain current performance (implies monitoring requirements) – Individual Variance: Permittee may apply for these if meeting the general variance is difficult. Requires case-by-case economic hardship analysis
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
§ , MCA Describes the “Nutrient Work Group” Describes the “Nutrient Work Group” – Broad cross-section of MT stakeholders – Advise DEQ on numeric nutrient standards, especially implementation policy – Have met with DEQ 15 times since May 2009 Nutrient trading policy developed Nutrient trading policy developed – Will allow for creation of nutrient credits and trading between point sources and point source-nonpoint sources
Draft Circular DEQ-12 and New Rules Contain: Criteria Criteria General variance procedures General variance procedures Individual variances Individual variances Permitting requirements Permitting requirements Non-degradation Non-degradation
New! EPA acceptance of Montana’s approach In an official memo (1/3/2012) USEPA states: “We recognize the strong science-based work MDEQ has conducted over the past several years to develop draft NNC for N and P for wadeable streams” “We recognize the strong science-based work MDEQ has conducted over the past several years to develop draft NNC for N and P for wadeable streams” “EPA concludes that the issuance of variances would be consistent with the Clean Water Act and its implementing regulations.” “EPA concludes that the issuance of variances would be consistent with the Clean Water Act and its implementing regulations.”
Timeline: Adoption of Statewide Nutrient Criteria Next NWG Meeting: 2/27/2012 (Helena, MT) Next NWG Meeting: 2/27/2012 (Helena, MT) More NWG meetings to follow (~ monthly) More NWG meetings to follow (~ monthly) Assuming details get worked out: Board package in July or September, 2012 Board package in July or September, 2012 – Public hearings, response to comments, modifications, etc. So…Need to get rule package to WPCAC this Spring So…Need to get rule package to WPCAC this Spring
Thank You Contact Information: (406) (406)