Water Quality Assessments. Report Steps

Transcription

1 Water Quality Assessments Fulfills CWA Sections 303(b) and 303(d) requirements Completed every two years Process includes public review and comment periods Final approval by EPA is required EPA can add waters to 303(d) list Report Steps Data gathering Data Analysis & Designated uses (DU) Assess overall water quality Based on Impaired Waters Identification Rule and ADEQ Assessment Technical Manual Listing and TMDL priorities Review & comment process

2 Data & Designated Uses Various Sources Internal, USGS, AGFD, USFWS, consultants, etc. Criteria Current: physical chemistry Future: biocriteria, nutrients (lakes), bottom deposits, fish tissue Designated Uses A&W AgI AgL FC DW BC Data Analysis Things we look for: Sufficient number of samples? Are samples distributed enough? Do samples include core parameters? Designated Use Aquatic & Wildlife Ag Irrigation Ag Livestock Fish Consumption Domestic Water Source Body Contact Not required if ephemeral If nutrients standard established Core Parameters D.O. Stream flow (if a stream) Sample depth (if a lake) Total nitrogen Total phosphorus Dissolved cadmium, copper, zinc & hardness Total boron & manganese Total copper & lead Total mercury Nitrate/nitrite or nitrate Fluoride Total arsenic, chromium or chromium VI, and lead E. coli

3 Assessment Groups Group A. A&W Chronic A&W Acute E. Coli (BC) Grab sample or 4 day median value Grab sample Grab sample > SSM & screening value Group B. (Minimum of 20 samples) BC, FC, DWS, AgI, AgL Grab sample = Exceedance Definition Nitrogen &Phosphorus (A&W, BC) Grab sample > SSM Assessment Gs Ctd. = Exceedance Definition Group C. Nitrate or Nitrate/Nitrite (DWS) E. Coli (BC) Suspended Sediment (A&W) Total Dissolved Solids (Colorado R) Grab sample Geometric mean of 4 samples taken during a 30 day period Annual mean of >3 monthly means 90 th percentile of >10 samples collected at least 10 days apart Geometric mean of >4 samples, excluding samples at elevated flows Flow weighted mean of all samples collected during a 12 month period

4 Assessment Process Sufficient # of samples? NoA, B, C Yes A,C Yes B 1 exceedance No exceedance A >2 exceedances > x exceedances < x exceedances No exceedance Impairment Distributed? Core Parameters? A,B Inconclusive No Yes Attainment No exceedance C Categories 1: Attaining All Uses 2: Attaining Some Uses 3: Inconclusive 4: Not Attaining 4A: TMDL Completed 5: Impaired, 303(d)

5 No Longer Listed A = Ok B = 4A Reach Split flow Naturally occurring conditions are the sole cause Change in standard Data reevaluation indicates error AgL New data collected during critical conditions Back to Attainment Group A. With seasonal distribution and core parameters A&W Chronic No exceedances A&W Acute No exceedances E. Coli (BC) No exceedances Group B. With a minimum of 10 samples BC, FC, DWS, AgI, AgL <2 with 10 minimum, etc. = Allowable Exceedances Nitrogen &Phosphorus (A&W, BC) <2 with 10 minimum, etc.

6 Attainment, ctd. = Allowable Exceedances Group C. Nitrate or Nitrate/Nitrite (DWS) E. Coli (BC) Suspended Sediment (A&W) Total Dissolved Solids (Colorado R) None least two monthly geomeans) least two annual means) least two 90 th percentiles) least two geomeans) least 2 annual flow weighted means) Where s the Report? The draft 2010 Integrated Report is currently published in the Arizona Administrative Register Upon completion of public notice it will be submitted to EPA for approval The 2012 Integrated Report is under internal review Public comment period should begin sometime this fall

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