R309-515-7. Ground Water - Springs

  (1) General.

  Springs vary greatly in their characteristics and they should be observed for some time prior to development to determine any flow and quality variations. Springs determined to be under the direct influence of surface water shall comply with surface water treatment requirements.

  (2) Source Protection.

  Public drinking water systems are responsible for protecting their spring sources from contamination. The selection of a spring shall only be made after consideration of the requirements of R309-515-4. Springs must be located in an area that shall minimize threats from existing or potential sources of pollution. A Preliminary Evaluation Report on source protection issues is required by R309-600-13(2). If certain precautions are taken, sewer lines may be permitted within a public drinking water system's source protection zones at the discretion of the Director. When sewer lines are permitted in protection zones both sewer lines and manholes shall be specially constructed as described in R309-515-6(4).

  (3) Surface Water Influence.

  Some springs yield water that has been filtered underground for years; other springs yield water that has been filtered underground only a matter of hours. Even with proper development, the untreated water from certain springs may exhibit turbidity and high coliform counts. This indicates that the spring water is not being sufficiently filtered in underground travel. If a spring is determined to be under the direct influence of surface water, it shall be treated to meet the surface water treatment requirements specified in R309-505-6.

  (4) Pre-construction Submittal

  Before beginning spring development construction, the following information shall be submitted to the Director and approved in writing:

  (a) detailed plans and specifications covering the development work;

  (b) if available, a copy of an engineer's or geologist's statement indicating:

  (i) the historical record of spring flow variation;

  (ii) expected minimum flow and the time of year it will occur;

  (iii) expected maximum flow and the time of year it will occur;

  (iv) expected average flow and,

  (v) the behavior of the spring during drought conditions;

  (c) acceptable evidence that the water system has a legal right to divert water for the proposed use(s) from the spring source(s);

  (d) a Preliminary Evaluation Report on source protection issues as required by R309-600-13;

  (e) a copy of the chemical analyses required by R309-515-4(5) ; and,

  (f) an assessment of whether the spring is under the direct influence of surface water(refer to R309-505-7(1)(a)).

  (5) Information Required after Spring Development.

  After development of a spring as a drinking water source, the following information shall be submitted to the Director for review.

  (a) proof of satisfactory bacteriologic quality;

  (b) information on the rate of flow developed from the spring.

  Immediately after spring development, the water system shall collect monthly spring flow data during operating seasons when the spring is reasonably accessible, as a minimum, for three years, and submit spring flow data to the Director for determination of spring yield. After evaluating the spring flow information including seasonal and annual variations, the Director will determine a spring yield, which will be used in assessing the number of and type of connections that can be served by the spring. The spring yield typically is set at the 25th percentile of the spring flow data. If the spring exhibits significant seasonal or annual variations, the spring yield may be assessed on a case-by-case basis.

  (c) Record drawings of spring development.

  (6) Operating Permit Required.

  Water from the spring can be introduced into a public water system only after it has been approved for use, in writing, as evidenced by the issuance of an Operating Permit by the Director (see R309-500-9).

  (7) Spring Development.

  The development of springs for drinking water purposes shall comply with the following requirements.

  (a) The spring collection device, whether it be collection tile, perforated pipe, imported gravel, infiltration boxes, or tunnels must be covered with a minimum of 10 feet of relatively impervious soil cover. Such cover must extend a minimum of 15 feet in all horizontal directions from the spring collection device. Clean, inert, non-organic material shall be placed in the vicinity of the collection device(s).

  (b) Where it is impossible to achieve the 10 feet of relatively impervious soil cover, an acceptable alternate will be the use of an impermeable liner provided that:

  (i) the liner has a minimum thickness of at least 40 mils;

  (ii) all seams in the liner are folded or welded to prevent leakage;

  (iii) the liner is certified as complying with ANSI/NSF Standard 61. This requirement is waived if certain that the drinking water will not contact the liner;

  (iv) the liner is installed in such a manner as to assure its integrity. No stones, two inch or larger or sharp edged, shall be located within two inches of the liner;

  (v) a minimum of two feet of relatively impervious soil cover is placed over the impermeable liner; and,

  (vi) the soil and liner cover are extended a minimum of 15 feet in all horizontal directions from the collection devices.

  (c) Each spring collection area shall be provided with at least one collection box to permit spring inspection and testing.

  (d) All junction boxes and collection boxes, must comply with R309-545 with respect to access openings, venting, and tank overflow. Lids for these spring boxes shall be gasketed and the box adequately vented.

  (e) The spring collection area shall be surrounded by a fence located a distance of 50 feet (preferably 100 feet if conditions allow) from all collection devices on land at an elevation equal to or higher than the collection device, and a distance of 15 feet from all collection devices on land at an elevation lower than the collection device. The elevation datum to be used is the surface elevation at the point of collection. The fence shall be at least "stock tight" (see R309-110). In remote areas where no grazing or public access is possible, an exception to the fencing requirement may be granted by the Director. In populated areas, a six-foot high chain link fence with three strands of barbed wire may be required.

  (f) Within the fenced area all vegetation having deep roots shall be removed by a means not negatively affecting water quality.

  (g) A diversion channel, or berm, capable of diverting all anticipated surface water runoff away from the spring collection area shall be constructed immediately inside the fenced area.

  (h) A permanent flow-measuring device shall be installed. Flow measurement devices such as critical depth meters or weirs shall be properly housed and otherwise protected.

  (i) The spring shall be developed as thoroughly as possible to minimize the possibility of excess spring water ponding within the collection area. Where the ponding of spring water is unavoidable, the excess shall be collected by shallow piping or french drain, and be routed beyond and down grade of the fenced area required above, whether or not a fence is in place.