Animal Waste, Water Quality and Human Health

342Animal Waste, Water Quality and Human Healthdiverted to a series of nine sand-bottomed infiltration/evaporation cells functioning as aconstructed wetland. In summer of 2000, the period of time immediately preceding there-engineering of the storm drain, the concentration of E. coli per 100 ml of storm waterexceeded 1000 cfu/100 ml on 36 out of 46 sampling events or 78 per cent of the time. Inthe summer of 2005 the concentration of E. coli per 100 ml of storm water exceeded1000 MPN/100 ml two out of 14 times or 14 per cent of the time, a reduction of 64percent (Kinzelman & Hiller 2007). The mean seasonal E. coli content in storm waterdischarging from this catch basin was reduced by two orders of magnitude alleviatingmany of the bathing water quality failures associated with wet weather events.Table 9.2Timeline of improvement initiatives, City of Racine, WI, USA.Timeline of Improvement Initiatives:2000: Re-engineering of storm water outfall begins; autumn of 2000 (includesboth a system for the mechanical removal of solid wastes and a series ofinfiltration/evaporation basins to retain first-flush storm water)2001: Initial beach grooming study conducted by Racine Health DepartmentLaboratory2002: Phase II beach grooming study, re-engineering of outfall completed,infiltration beds planted with native wetland plant species2003: New beach grooming techniques implemented; provides a 30% reduction indry weather advisories, signs posted prohibiting feeding of seagulls, citystorm drains placarded –“no dumping, drains to lake”2004: Additional storm drains placarded and more wetland plants added to stormwater outfall site2005: Beach slope improved, swales removed, and berm crest enhanced to reducetransport of bacteria from beach sands to near shore waters, additionalstorm drains placarded, weekly median E. coli level from storm waterdischarge points drops from 3000 MPN/100 ml to 41 MPN/100 ml2006: Beach grooming and grading continue according to new best managementpractices, additional waste receptacles (with liners) added in life-guardedareas, algae & aquatic plant removal occurs as necessary, educationalsignage installed on Lake Michigan pathway2007: Created dunes are used to manage blowing sand, washouts filled in aftersignificant rain events, routine/annual beach sanitary surveys conducted,ongoing predictive modelling and QPCR studiesIn order to address dry weather bathing-water quality failures a series of beach sandmanipulation measures were executed. Previous beach grooming techniques provided anaesthetically pleasing and debris-free beach, but significantly increased bacterialindicator organism density when beach sands were wet (Kinzelman et al. 2003,