The fate of wastewater effluents discharged from 17 septic tank disposal systems located near the shores of eight lakes in northeastern and eastern New York State was investigated. Fecal coliforms chloride, conductivity, dissolved 0₂, phosphate and various forms of N in ground water samples were analyzed. Of 46 ground water samples, 23 were found to be highly contaminated and 16 slightly contaminated. Only 7 were not contaminated by the wastewater effluent. Seventeen of the 23 highly contaminated samples were collected within 30.5 m of the discharge point of the septic systems. Eleven of these were collected from ground water less than 122 cm below ground level. Eight of the 16 slightly contaminated samples and 3 of the 7 noncontaminated samples were collected at a distance greater than 30.5 m. The depth to the ground water from ground surface and the distance of the ground water from the discharge point of the sewage system are main factors influencing pattern and severity of ground water contamination. This survey indicated that significant nutrient and fecal coliform contamination of lakeshore ground waters was occurring.