December 2006 report of the academic advisory committee to Virginia department of environmental quality: Freshwater nutrient criteria for rivers and streams
Zipper, CE; Yagow, G; Walker, JL; Smith, EP; Shabman, LA; Smock, LA; Hershner, CH; Younos, T; Benfield, EF; Bukaveckas, PA; Garman, GC; Kator, HI; Lung, WS; Stephenson, K
HERO ID
3608227
Reference Type
Technical Report
Year
2007
Language
English
| HERO ID | 3608227 |
|---|---|
| Year | 2007 |
| Title | December 2006 report of the academic advisory committee to Virginia department of environmental quality: Freshwater nutrient criteria for rivers and streams |
| Authors | Zipper, CE; Yagow, G; Walker, JL; Smith, EP; Shabman, LA; Smock, LA; Hershner, CH; Younos, T; Benfield, EF; Bukaveckas, PA; Garman, GC; Kator, HI; Lung, WS; Stephenson, K |
| Publisher Text | Virginia Water Resources Research Center |
| Abstract | This report reviews activities conducted by the Academic Advisory Committee to the Virginia Department of Environmental Quality (DEQ) between July and December 2006. Activities were conducted for the purpose of developing recommendations for DEQ regarding nutrient criteria for freshwater rivers and streams. In its June 2006 report to DEQ, the AAC recommended that DEQ establish nutrient criteria for rivers and streams by addressing independently the two effects described by the Environmental Protection Agency (EPA): localized and downstream-loading effects. The current report and activities address nutrient criteria development within that framework. Section I of this report addresses the development of screening values for wadeable streams. Reference (i.e., characteristics of relatively undisturbed or least disturbed streams) and effect-threshold concentrations for in-stream nutrients that have been suggested by other studies are reviewed. Reference values for total nitrogen (TN) and total phosphorus (TP) tend to vary by U.S. EPA's Nutrient Ecoregions and are generally higher in the eastern portions of the state than in the west. Effect-threshold values derived from other studies tend to vary more widely in part due to the variety of effect endpoints that have been employed in developing these threshold-concentration estimates. A review of TMDL studies that have been completed for nutrient-impaired streams revealed few usable reference concentrations because they are generally load-based studies (and do not report the streamflow information that could be used to calculate nutrient concentrations). An analysis of DEQ monitoring data found that Stream Condition Index (SCI, an indicator of benthic macroinvertebrate community status) values tend to vary negatively with nutrient concentrations. When using a statewide data set, these data allow the development of statistically significant regression models of the in-stream nutrient-SCI relationships. Application of these models yields "critical values" (i.e., nutrient values corresponding with the SCI = 60 impairment threshold) for TN (0.8 mg/L), total Kjeldahl nitrogen (TKN) (0.3 mg/L), and TP (0.05 mg/L). However, even after a data-selection process intended to focus analysis on sites where no influence by non-nutrient stressors is evident, the variability of SCI response to nutrients is large; thus, the analysis did not allow direct derivation of appropriate screening values. |
| Report Number | VWRRC Special Report SR33-2007 |
| Url | http://www.vwrrc.vt.edu |
| Is Certified Translation | No |
| Dupe Override | No |
| Number Of Pages | 66 |
| Comments | Journal:Special Report. Virginia Water Resources Research Center |
| Is Public | Yes |
| Language Text | English |
| Keyword | USA, Virginia; Rivers; Screening; Water resources; Nutrients (mineral); Zoobenthos; Inland water environment; Environmental protection; Stream flow; Reviews; Environmental Quality; Streamflow; Nutrients; Monitoring; Streams; Model Studies; Nitrogen; 2007) |
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