ET-3A1 (2/1/05 version)
Environmental Targets And Priorities Overview: Key NPS Causes Of Surface Water Quality Nonattainment

2004 Integrated Report Statistics, Watershed Assessment Units (WAUs)
  Total Number Ohio WAUs: 331  
  Number WAUs Monitored (1993-2002): 249  
  Number WAUs Impaired: 242  
  Number Ohio WAUs Unassessed: 75  

Details for each individual assessed WAU are available in the 2004 Integrated Water Quality Monitoring and Assessment Report

Table 1. WAU Recreational Use Impairments Caused by Bacteria
  Number WAUs monitored Number WAUs Impaired % of Monitored Total  
  151 103 68%  

88% (198 out of 225) of WAUs assessed for aquatic life use attainment have at least one stream/river impaired by at least one NPS-related cause. Specifics are summarized in Table 2 and associated hyperlinks.

Table 2. WAU Aquatic Life Use Impairments, by NPS-related Causes*
  NPS cause Number WAUs monitored Number WAUs Impaired % of Monitored Total
  Silt/sediment 225 117 52%
  Contaminated sediment 225 11 5%
  Nutrients 225 94 42%
  Habitat Modification 225 137 61%
  Hydromodification 225 102 45%
* NPS causes (PDF 49kb)are listed as high magnitude for at least one stream/river within the WAU

 

2004 Integrated Report Statistics, Large River Assessment Units (LRAUs)
  Total Number Ohio LRAUs: 23  
  Number LRAUs Monitored (1993-2002): 22  
  Number LRAUs Impaired: 20  
  Number Ohio LRAUs Unassessed: 1  

Details for each individual assessed LRAU are available in the 2004 Integrated Water Quality Monitoring and Assessment Report.

Table 3. LRAU Recreational Use Impairments Caused by Bacteria
  Number LRAUs monitored Number LRAUs Impaired % of Monitored Total  
  15 9 60%  

62% (13 out of 21) LRAUs assessed for aquatic life use attainment are impaired by at least one NPS-related cause. Specifics are summarized in Table 4 and associated hyperlinks.

Table 4. LRAU Aquatic Life Use Impairments, by NPS-related Causes*
  NPS cause Number LRAUs monitored Number LRAUs Impaired % of Monitored Total
  Silt/sediment 21 7 33%
  Contaminated sediment 21 3 14%
  Nutrients 21 5 24%
  Habitat Modification 21 9 43%
  Hydromodification 21 7 33%
* NPS causes (PDF 8kb) are listed as high magnitude for at least one reach within the LRAU