THE EFFECT OF INDICATOR ORGANISMS IN WASH WATER DISPOSAL ON MOORING EMBAYMENTS

With the increase in the number of recreational boats in Ontario's wat erways, there is growing concern that discharges of wash water may be causing local water quality problems. Bacterial loadings were determin ed from measurements on a sailboat, power cruiser, and houseboat over a period of 15 to 18 days. Composition of the boat crews was changed t hree times. There were 286 samples analyzed. The receiving water impac t of the wash water discharges was measured in three confined embaymen t anchorages. The range of freshwater use was between 17 and 22 L/pers on/day. The geometric range of fecal coliform (FC) densities was found to be in the 10(5) to 10(8)/100 mL, however the Escherichia coli comp onent of the fecal coliform component was only 6 percent. Wash water d ischarge loadings could cause the receiving water fecal coliform densi ties to exceed 100FC/100 mL in two of the three embayments studies, ho wever the public health significance of the findings is questionable. Receiving water bacterial densities are functions of the number of boa ts, size of the embayment, and the water exchange in and out of the em bayment. A predictive model was developed.