OAR 333-061-0075: Sanitary Surveys of Watersheds

(1) In water systems utilizing surface water sources or groundwater sources under the direct influence of surface water that do not provide filtration treatment, the water supplier shall conduct sanitary surveys of the watershed as deemed necessary by the water system to meet the requirements of OAR 333-061-0032(2)(b)(B). The results of the watershed survey will be reviewed by the Authority during the annual on-site inspection required by OAR 333-061-0032(2)(b)(C). The Authority recommends that systems which do provide filtration treatment for surface water sources or groundwater sources under the direct influence of surface water also conduct annual sanitary surveys of the watershed. (2) The survey shall include but not be limited to, an evaluation of the following man made and natural features in the watershed and their effect on water quality: (a) Nature of and condition of dams, impoundments, intake facilities, diversion works, screens, disinfection equipment, perimeter fences, signs, gates; (b) Nature of surface geology, character of soils, presence of slides, character of vegetation and forests, animal population, amounts of precipitation; (c) Nature of human activities, extent of cultivated and grazing land, zoning restrictions, extent of human habitation, logging activities, method of sewage disposal, proximity of fecal contamination to intake, recreational activities and measures to control activities in the watershed; (d) Nature of raw water, level of coliform organisms, vulnerability assessments of potential contaminants, algae, turbidity, color, mineral constituents, detention time in reservoir, time required for flow from sources of contamination to intake; (e) Type and effectiveness of measures to control contamination, and algae, disinfection applications and residuals carried, monitoring practices, patrol of borders. (3) A report on the findings of the survey shall be submitted annually to the Authority as required by OAR 333-061-0040(1). (4) The Authority recommends using the guidelines in the US EPA Guidance Manual for Compliance with the Filtration and Disinfection Requirements for Public Water Systems Using Surface Water Sources to construct an effective watershed control management plan. A list of additional references recommended by the Authority is available upon request. [Publications: Publications referenced are available from the agency.]