1 / 29

Implementing river eutrophication standards

Implementing river eutrophication standards. Dennis Wasley. Acknowledgements. Steve Weiss, Katrina Kessler, Marco Graziani Steve Heiskary, Mark Tomasek, Will Bouchard, Shannon Lotthammer, Howard Markus Watershed outlet monitoring staff Pat Baskfield and Steve Thompson

biana
Download Presentation

Implementing river eutrophication standards

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Implementing river eutrophication standards Dennis Wasley

  2. Acknowledgements • Steve Weiss, Katrina Kessler, Marco Graziani • Steve Heiskary, Mark Tomasek, Will Bouchard, Shannon Lotthammer, Howard Markus • Watershed outlet monitoring staff • Pat Baskfield and Steve Thompson • Chuck Regan, Tim Larson, Travis W. and Larry Gunderson • Watershed staff • others...

  3. Overview • How effluent limits are set • River nutrient standards • Summer average • Long-term average • Response variables • Non-point sources are very important • Streamflow • Examples

  4. Topics to consider • Importance of quality flow and water-quality monitoring • Tools to analyze data • Communication of results • TMDLs, timelines

  5. Draft river eutrophication criteria (summer-means) • Assessments based on minimum of 2 summers & 6 or more obs./summer; • Must exceed cause & one or more response (stressors)to be deemed impaired; • existing pH standard may be used also

  6. River Nutrient Regions (RNR) • Regionalized criteria because of distinct differences among landform, land use, soil type, & stream water quality in MN • Consistent with lake criteria approach; • EPA Ecoregion map was base map: • Rivers classified based on relative ecoregion composition & • Changes in reach-specific WQ;

  7. Stream description Suspended algae Periphyton Headwater stream Very limited Common dependent on habitat (1-2 order) Large stream Limited? Common dependent on habitat (HUC 10 ) Need more data River Common Present dependent on habitat (HUC 8) Large River Abundant Limited in main channel (6-8 order)

  8. Effluent limits 101 (RES standards) • Establish background concentration of stream • Background concentration is dynamic for TP over summer period • Calculate load from facility • Standard applies during wet and dry times • Determine if load from facility drives concentration in stream above standard during a critical condition • Requires extensive concentration and flow data for stream • Dilution is the Solution • High flows do not always offer dilution

  9. There is more than 1 way to meet 150 ug/L (ug/L) High flow Low flow

  10. Example watershed: source contributions

  11. Examples

  12. Bigfork River (meets RNS) High flow Low flow

  13. Bigfork River (daily loads)

  14. Bigfork River • Very minimal point sources • Non-point only exceeds standard at highest flows • This is expected and complies with RNS • Downstream impairment in Lake of the Woods (LOW) • Existing limits in Bigfork watershed will be adopted by LOW TMDL • Boise Cascade, North Kooch larger point sources • Complicated lake

  15. Cottonwood River • TP exceeds RNS at watershed outlet • Response data is very limited • Downstream rivers do exceed both TP and response variable • Extensive non-point sources in cottonwood and downstream watersheds

  16. Cottonwood TP concentration (mg/L) RES 0.150 (mg/L)

  17. Cottonwood TP load (kg/day) FLUX load RES Point source

  18. Watershed model: HSPF • Model impacts of multiple point sources • Model scenarios of various watershed BMPs • Model transport and transformations • Models are tools

  19. Downstream impacts

  20. Point source locations in Cottonwood Minnesota R. at Jordan Cottonwood at New Ulm Minnesota R. Mankato

  21. HSPF modeled TP for the Minnesota River downstream of Mankato RES 0.150

  22. South Fork Crow River • Large point and non-point contributions • Recent point source reductions • Clearly exceeds TP and response variables of RNS • Restrictive WWTP limits and considerable non-point reductions will be needed to meet RNS

  23. SF Crow River (high TP at all flows)

  24. SF Crow loads

  25. SF Crow • Considerable non-point reductions needed • Very difficult to drive concentration at moderate to high flows below 0.150 mg/L • Existing point sources overwhelm background at moderate to low flows • Could assume 0.075 – 0.10 mg/L based on other watersheds • Tremendous algal production at low flows • Low flow is really low flow in SF Crow?

  26. Headwaters / small rivers • Analyze data from 10x nutrient site when its available • Proceed with same process as outlined in examples • Advantages of 10x nutrient sites • Minimizes compliance points • Avoid impacts of impaired lakes • Consistent monitoring program • Stream should flow for nearly all summer days • Limited data at immediate reach • Set limits for downstream impairments

  27. SF Crow River 10x sampling sites

  28. Summary • Set limits on downstream reach with adequate data to make calculations • MPCA wants to be right the first time • Watershed approach, TMDLs and additional monitoring will refine original limit calculations • Non-point reduction considerations are critical to our approach • This is especially true during moderate to high flows

More Related