Section NR 811.21 - General requirements Surface water sources include all lakes, rivers, and streams. The source of water selected by the water system owner as a surface water supply shall be from the best available source practicable. The source shall provide the highest quality water reasonably available which, with appropriate treatment and adequate safeguards, will meet the drinking water standards under ch. NR 809. The water system owner shall contact the department's office of energy to initiate pre-application consultation regarding ch. 30, Stats., permitting. Any proposal that will result in a diversion from the Great Lakes basin requires department approval under s. 281.346, Stats. A water system that utilizes a surface water source shall meet all of the following requirements:
(1) QUALITY. The water system owner shall conduct an investigative study that includes both natural and man-made factors that may affect water quality of the selected surface water supply. The study shall include all of the following: (a) Determining possible future uses of the water body.(b) Determining degree of control of the watershed by the water system.(c) Assessing degree of hazard to the water supply by agricultural, industrial, recreational, shipping and residential activities in the watershed, and by accidental spillage of materials that may be harmful or detrimental to the treatment process.(d) Assessing all waste discharges, point source and non-point source, and activities that could impact the water supply. The location of each waste discharge shall be shown on a scale map.(e) For lakes, an analysis of the area water currents and for streams, an analysis of streamflows, and their potential impact on water quality. Consideration shall be given to potential wind and ice conditions.(f) Obtaining samples that are representative of the proposed intake structure based on depth and location. Parameters that may be subject to seasonal variation shall be taken for a period of up to one year or over a sufficient period of time to assess such variation. Testing shall include turbidity, pH, alkalinity, hardness, bromide, total organic carbon, color, taste and odor, ammonia, microbiological organisms, heavy metals including lead and copper, volatile organics, synthetic organics, inorganics, and radiological characteristics of the water. The microbiological testing shall satisfy the Long Term 2 Enhanced Surface Water Treatment Rule requirements found in ss. NR 809.33 to 809.335. The source water shall meet the surface water quality standards in ch. NR 102.(2) QUANTITY. The quantity of the water at the source shall:(a) Be adequate in conjunction with water from other existing sources to meet the maximum 20-year projected water demand of the service area, as shown by calculations based on a one in 50-year drought or the extreme drought of record, and shall include multiple year droughts. Note: The department recommends water systems using a surface water supply source are provided with redundant intakes or an alternative means of supplying the maximum day water demand.
(b) Provide a reasonable reserve for anticipated growth.(c) Be adequate to provide ample water for other legal users of the source in accordance with ss. 30.18, 31.02, 281.35, and 281.41, Stats., and ch. NR 142.(3) LOCATION. The inlet for the intake shall not be located:(a) Within 1,000 feet of boat launching ramps, marinas, docks, or floating fishing piers which are accessible by the public.(b) In areas subject to excessive siltation or in areas subject to receiving immediate runoff from wooded sloughs or swamps.(c) Within 1,000 feet of a wastewater treatment plant outfall outlet.(4) MINIMUM TREATMENT. The design of the treatment processes, equipment, and structures shall depend on an evaluation of the nature and quality of the particular water to be treated. (a) The design of the water treatment plant must consider the worst conditions that are projected to occur during the life of the facility.(b) Filtration preceded by appropriate pretreatment shall be provided for all surface waters.(c) Disinfection shall be provided for all surface waters.(d) Additional treatment may be required by the department based on raw water sampling and other water quality factors.Wis. Admin. Code Department of Natural Resources NR 811.21
CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.Amended by, CR 22-074: am. (intro.), (1) (intro.), (b), (e), (2) (a) Register January 2024 No. 817, eff. 2/1/2024