Assessment Comments

Assessment is based on (1) results of IDNR/UHL ambient monthly water quality monitoring from 2002-04 near Ackworth and (2) best professional judgement of IDNR staff.

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life are assessed (evaluated) as "fully supported”.   The source of data for this assessment is the results of IDNR ambient monthly monitoring during the 2002-2004 assessment period at STORET station 10910003 (formerly station 426046) at the Highway 92 bridge near Ackworth.  

EXPLANATION:  The Class B(LR) aquatic life uses were assessed as "fully supported".   None of the 36 samples collected during the 2002-2004 assessment period at the IDNR/UHL monthly station violated Class B(LR) water quality criteria for pH, dissolved oxygen, or ammonia-nitrogen; no violations occurred in the approximately 10 samples analyzed for metals, pesticides and other toxic organic compounds.   These results suggest full support of the Class B(LR) aquatic life uses.   Although results of chemical monitoring suggest relatively good water quality and “full support” of the aquatic life uses of this river segment, previous assessments have indicated potential impacts due to alteration of aquatic habitats (see, for example, the  assessment for the 1994 305(b) report).   Biological monitoring is needed to better define the status of aquatic communities in this river segment.