Ottumwa Lagoon IA 04-LDM-1014

Assessment Comments

Basis for Assessment

Used assessment of support of the Class B(LW) aquatic life uses (=PS) developed for the 1994 report.  Two large CSOs which discharge into the Ottumwa Lagoon are a source of pathogens associated with sanitary waste.  The Finley CSO was observed discharging into Ottumwa Lagoon on 5/22/95 following a 2-3" rain.  A number of floating solids were observed coming from the CSO discharge.  Class A swimming use was assessed as NS based on DNR staff judgement that waterbody would not be fit for swimming use as long as CSOs continue to discharge directly into Lagoon.  Local recognition of the problem or posted advisories against swimming may explain why Bachmann et al (1994) report that swimming use is non existent.