Section 382.365. Stormwater and clearwater subsurface infiltration plumbing systems.

 

(1)   Scope. The provisions of this section set forth the requirements for the design, installation and maintenance of stormwater and clearwater subsurface infiltration plumbing systems serving building sites.

(2)   Site and soil evaluation.

(a) Site evaluation. A site evaluation shall be conducted in accordance with the methods and standards as provided in s. SPS 385.40 (3) (a) .

(b) Soil evaluation.

1. A soil evaluation shall be conducted in accordance with the methods and standards as provided in s. SPS 385.30 (1) (c) .

2. Individuals qualified to conduct soil evaluation under this subsection shall be an individual that maintains either a registration as provided in s. SPS 305.33 or a license as provided in ch. GHSS 4 .

(3)   Infiltration system design.

(a) Influent quality. For stormwater and clearwater infiltration plumbing systems, the influent quality shall comply with the requirements in Table 382.70-1 for subsurface infiltration and irrigation.

(b) In situ soil requirements.

1. Except as provided in subd. 2. , the minimum depth of suitable in situ soil for infiltration systems shall be as specified in Table 382.365-1 to separate the system from the highest groundwater elevation or bedrock. When groundwater mounding calculations affect the depth to seasonal groundwater, the depth of suitable soil shall be measured to the calculated elevation of mounded groundwater.

2. For roof runoff or where treatment has afforded an equivalent level of water quality, the depth of in situ soil shall be no less than one foot of materials finer than coarse sand.

(c) Hydraulic application rates. The maximum hydraulic application rate for stormwater and clearwater subsurface infiltration plumbing systems shall be in accordance with one of the following methods.

1. The maximum hydraulic application rate shall be determined by soil analysis in accordance with sub. (2) (b) and Table 382.365-2.

2. The maximum hydraulic application rate shall be determined by field measurement using a nationally-accepted method and the correction factor as determined using Table 382.365-3. To determine the maximum hydraulic application rate, the measured infiltration rate at the infiltrative surface shall be divided by the correction factor as listed in Table 382.365-3. - See PDF for table

(d) Groundwater mounding. Groundwater mounding consideration shall be included in the design of any stormwater and clearwater subsurface infiltration plumbing system that has a width that exceeds 15 feet and a depth to the estimated highest groundwater elevation.

(e) Drain down time.

1. Stormwater and clearwater subsurface infiltration plumbing systems shall be designed to drain within 72 hours after a storm event.

2. By design, ground surface ponding shall drain within 24 hours after a storm event.

(f) Setbacks.

1. Stormwater and clearwater subsurface infiltration plumbing systems shall be located as provided in Table 382.365-4, except for irrigation systems. - See PDF for table

2. All stormwater and clearwater subsurface infiltration plumbing systems shall be separated from water wells by the applicable separation distances contained in chs. NR 811 and 812 or as otherwise approved by the department of natural resources.

(4)   Installation.

(a) Orientation. Except for subsurface irrigation systems, all of the following shall apply:

1. The longest dimension of a stormwater or clearwater subsurface infiltration plumbing system consisting in part of in situ soil shall be oriented along the surface contour of the site location, unless otherwise approved by the department.

2. The infiltrative surface of a stormwater or clearwater subsurface infiltration plumbing system consisting in part of in situ soil and located below the surface of the original grade shall be level.

(b) Other requirements.

1. A stormwater or clearwater subsurface infiltration plumbing system consisting in part of in situ soil may not be installed if the soil is frozen at the infiltrative surface.

2. Snow cover shall be removed before excavating or installing a stormwater or clearwater system component consisting in part of in situ soil.

3. For a stormwater or clearwater subsurface infiltration plumbing system consisting in part of in situ soil, the soil moisture content shall be evaluated immediately prior to installation of the component. If the soil evaluation at the infiltrative surface results in the sample capable of being rolled into a ¼ –inch wire, the installation may not proceed.

4. All vessels and pipes of a stormwater or clearwater subsurface infiltration plumbing system shall be bedded in accordance with a product approval under s. SPS 384.10 or a plan approval under s. SPS 382.20 .

(5)   Operation and maintenance.

(a) General. Operation and maintenance shall be performed in accordance with the operation and maintenance plan submitted with the stormwater and clearwater subsurface infiltration plumbing system design and s. SPS 382.36 (13) , where applicable.

(b) Prohibited substance.

1. Except as provided in subd. 2. , no substance shall be discharged into a stormwater or clearwater subsurface infiltration plumbing system that results in exceeding the enforcement standards and preventive action limits specified in ch. NR 140 Tables 1 and 2 at a point of standards application, pursuant to s. 160.21 (2) , Stats.

2. Pursuant to s. 160.19 (2) (a) , Stats., the department has determined that it is not technically or economically feasible to require that a stormwater or clearwater subsurface infiltration plumbing system treat wastewater to comply with the preventive action limit for chloride specified in ch. NR 140 Table 2, as existed on June 1, 1998.

3. Pursuant to s. 160.21 (2) , Stats., the point of standards application relative to the performance of stormwater and clearwater subsurface infiltration plumbing systems is any of the following:

a. Any point of present groundwater use for potable water supply.

b. Any point beyond the boundary of the property on which the facility, practice or activity is located.

(c) Deleterious substance. Substances deleterious to a stormwater or clearwater subsurface infiltration plumbing system shall be intercepted, diluted or treated in accordance with s. SPS 382.34 prior to the substance discharging into a stormwater or clearwater infiltration system.

CR 04-035 : cr. Register November 2004 No. 587 , eff. 12-1-04; correction in (2) (a), (b) 1., 2., (3) (a), (b) 1., (c) 1., 2., (f) 1., (4) (b) 4., (5) (a), (c), Table 382.365-3 made under s. 13.92 (4) (b) 7. , Stats., Register December 2011 No. 672 .

Note

The department of natural resources has registration requirements for class V injection wells. See ch. SPS 382 Appendix for further explanatory material. Microsoft Windows NT 6.1.7601 Service Pack 1 See ch. SPS 382 Appendix for representative water quality levels. - See PDF for table - See PDF for table Microsoft Windows NT 6.1.7601 Service Pack 1 a Use sandy loam design infiltration rates for fine sand, loamy fine sand, very fine sand, and loamy fine sand soil textures. Microsoft Windows NT 6.1.7601 Service Pack 1 b Infiltration rates represent the lowest value for each textural class presented; based on Rawls et al., 1998 [Use of Soil Texture, Bulk Density and Slope of Water Retention Curve to Predict Saturated Hydraulic Conductivity, ASAE, Vol. 41(2), pp. 983-988]. Microsoft Windows NT 6.1.7601 Service Pack 1 c Infiltration rate is an average, based on Rawls et al., 1982 (Estimation of Soil Water Properties, Transactions of the American Society of Agricultural Engineers Vol. 25, No. 5 pp. 1316 –1320 and 1328) and Clapp & Hornberger, 1978 (Empirical equations for some hydraulic properties. Water Resources Research 14:601-604). - See PDF for table - See PDF for table Microsoft Windows NT 6.1.7601 Service Pack 1 a Ratio is determined by dividing the design infiltration rate from Table 382.365-2 for the textural classification at the bottom of the infiltration device by the design infiltration rate from Table 382.365-3 for the textural classification of the least permeable soil horizon. The least permeable soil horizon used for the ratio should be within five feet of the bottom of the device or to the depth of the limiting layer. Microsoft Windows NT 6.1.7601 Service Pack 1 An acceptable model is provided by the USGS, webpage: http://water.usgs.gov/ogw/techniques.html . Microsoft Windows NT 6.1.7601 Service Pack 1 See ch. SPS 382 Appendix A-382.30 (11) (d) for material reprinted from ss. NR 811.12 (5) (d) and 812.08 . Section NR 811.12 (5) (d) or 812.08 may have additional setback requirements. Microsoft Windows NT 6.1.7601 Service Pack 1 To accomplish a field test for soil wetness, a soil sample the size of one's palm may be rolled to form at least a ¼ -inch wire. Microsoft Windows NT 6.1.7601 Service Pack 1 For groundwater standard limits on various substances, refer to ch. NR 140 Table 1. Microsoft Windows NT 6.1.7601 Service Pack 1 Section 160.19 (2) (a) , Stats., reads: "Each regulatory agency shall promulgate rules which define design and management practice criteria for facilities, activities and practices affecting groundwater which are designed, to the extent technically and economically feasible, to minimize the level of substances in groundwater and to maintain compliance by these facilities, activities and practices with preventive action limits, unless compliance with the preventive action limits is not technically and economically feasible." Microsoft Windows NT 6.1.7601 Service Pack 1