Nutrient Criteria for Streams and Rivers

793 views

Published on

Nutrient Criteria for Streams and Rivers EPA Framework for Nutrient Reduction

Texas Water Conservation Association
Water Quality Subcommittee
October 13, 2011

Jim Davenport
WQ Monitoring & Assessment Section
WQ Planning Division Office of Water, TCEQ

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
793
On SlideShare
0
From Embeds
0
Number of Embeds
175
Actions
Shares
0
Downloads
9
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Nutrient Criteria for Streams and Rivers

  1. 1. Nutrient Criteria for Streams and Rivers EPA Framework for Nutrient ReductionTexas Water Conservation AssociationWater Quality SubcommitteeOctober 13, 2011Jim DavenportWQ Monitoring & Assessment SectionWQ Planning DivisionOffice of Water, TCEQ Pedernales River Image by: Texas Water Development BoardTel. 512/239-4585
  2. 2. TCEQ Nutrient Criteria: Development Submitted plans to EPA in 2001, 2006 Reservoirs, then streams & estuaries Convened advisory workgroup Based on data for each reservoir Proposed for 93 reservoirs - Stand-alone Chl a criteria - Chl a criteria, + screening levels: TP, transparency Adopted for Chl a for 75 reservoirs, 6/30/10
  3. 3. EPA Review WQ Standards • Adopted by TCEQ - 6/30/2010 • Additional documentation to EPA - 8/4/2011 • EPA request for more information regarding nutrient criteria - 5/17/2011 Standards Implementation Procedures • Approved by TCEQ 6/30/2010 Lake Bridgeport Image by: TRWD • Comments from EPA 12/2/2010 letter
  4. 4. Summary of Current Plans Develop criteria option for selected rivers and estuaries based on historical conditions - Individual water bodies - Reference groupings Develop criteria option for streams and rivers based on stressor/response analyses Initiate additional options for estuaries based on ongoing efforts (e.g., stressor/response) Revisit reservoir criteria Consider ways to incorporate weight-of-evidence Develop implementation options
  5. 5. Why Are Nutrient Criteria Difficult? Lack of clear “use-based” thresholds for uses such as recreation & aesthetics, aquatic life propagation, drinking water sources Responses to nutrients are highly variable – e.g., effect of TN and TP on Chl a No consensus on how to derive criteria Independent criteria or “weight-of evidence”? Insufficiencies in historical monitoring data Initial EPA guidance criteria were problematic High concern about regulatory impacts
  6. 6. Streams & Rivers: Challenges Limited data for TN and relative abundance of attached algae Regional, hydrologic, chemical variability Grouping streams and rivers Parameters? TP, TN, Chl a, % cover … Weight-of-evidence – Development, Assessment Effluent-dominated streams / attainability Reasonable implementation
  7. 7. Tx Streams: Instream DilutionFor 358 major domestic discharges:% effluent instream at 7Q2 No. of discharges 0 - 25% 57 (16%) 26 - 50% 32 ( 9%) 51 - 75% 47 (13%) 76 - 99% 122 (34%) 100% 100 (28%)
  8. 8. Available Data – Streams and Rivers 30-40 years of data at 100’s of stations, for TP, ~TN, Chl a, Transparency, D.O., etc. plus frequent fish, invertebrate sampling Data and Research Needs • Algae Sampling – attached periphyton sampling • Representative Stations • More TN data • Lower TP and TN detection limits Recent Stream and River Projects • Regional nutrient sampling studies of streams • Statistical responses to N & P – historical data • Peer review of other states, prognosis for Texas • Additional studies
  9. 9. The Road Ahead: Streams & Rivers Categorize and group based on  Geography?  Hydrology?  Chemical similarities? Option 1: Base criteria on historical levels in reference streams and rivers Option 2: Stressor/response analyses, relating TN,TP to biological indices, D.O., Chl a (in rivers), attached algae (smaller streams)
  10. 10. EPA Framework for State Nutrient Reductions  EPA Memo from Nancy Stoner, 3/16/2011  Summarizes 8 key elements needed for state programs to reduce nutrient loadings  Intended as a flexible planning toolLeft: Water JetsImage by: CSTARSRight: A Texas Estuary
  11. 11. EPA Framework for State Nutrient Reductions: Eight Key Elements Prioritize watersheds on a statewide basis Set watershed load reduction goals Ensure effectiveness of point source permits Agricultural areas Storm water and septic systems Accountability and verification measures Annual public reporting of implementation activities & biannual reporting of load reductions Develop work plan, schedule for numeric criteria
  12. 12. Recent Activities 3/10/11 EPA (Jackson) addresses U.S. House Committee on Ag, re: nutrient criteria 3/16/11 EPA memo on nutrient framework 5/24/11 EPA VI requests responses to memo 6/23/11 ASIWPCA letter, urging flexibility for framework, “weight-of-evidence” for criteria 8/23/11 TCEQ provides initial response to memo 10/4/11 U.S. Senate subcommittee on nutrients 10/5/11 States meet with EPA on flexibility & weight of evidence for nutrient criteria
  13. 13. EPA Nutrient Framework Initial TCEQ Response (8/23/11) TCEQ is already implementing many elements: - Reservoir nutrient criteria, continuing efforts - New standards implementation procedures - Watershed efforts by TCEQ and TSSWCB - Increased studies, monitoring efforts Resource/regulatory impact concerns - Texas has ~ 210 8-digit HUC watersheds TCEQ amenable to discussion with EPA
  14. 14. 2010 Nutrient Implementation Procedures In 2010 Standards Implementation Procedures Applied to increases in domestic discharges Sets framework for nutrient (TP) effluent limits Reservoirs – predict effects on “main pool” Reservoirs – assess local impacts - Apply site-specific screening factors - Level of concern – low, moderate, or high - Assess “weight-of-evidence” Streams – assess local impacts (as for reservoirs)
  15. 15. Nutrient Criteria & Management Concluding Notes• EPA review of 2010 nutrient criteria continues• Focus of options for stream nutrient criteria: - Historical reference conditions - Observed responses to N & P (existing data) - Incorporating “weight of evidence” - Flexibility for implementation• Discussions on EPA framework are pending• Questions / Comments?

×