Section 110.10. Sewage collection system projects.

 

(1)   Facilities plans for sewer projects. For sewer projects the facilities plan shall include the following information:

(a) Description. A brief description of the project; including its geographic location and any necessary reference maps or exhibits.

(b) Topography. A brief description of the topography of the general area with specific reference to the area serviced by the proposed sewer.

(c) Soil investigations. A description of the extent of soil investigations, including information on rock likely to be encountered. In addition, that portion of the proposed sewer which is below high ground water level shall be indicated.

(d) Flooding. A designation of any portion of the proposed sewer which is located within the floodway or floodplain as defined in ch. NR 116 . All projects shall conform to the requirements of ch. NR 116 .

(e) Wetlands. A statement indicating whether the proposed sewer will pass through a wetlands area, and the approximate acreage of the wetland.

(f) Population. Population growth rate (annual) based on the most recent data for the municipality.

(g) Sewer service area. If the sewer project is tributary to a treatment plant for which a service area that has been delineated as a part of an approved areawide waste treatment management plan, indicate the location of the sewer on a map of the service area.

(h) Downstream overflows. A description of the number and location of sanitary sewer overflow structures and a description of the occurrence of sanitary sewer overflow events at any location within the sewerage system.

(i) Description of treatment facilities. A brief description of the type of treatment facility indicating the ability of the facility to handle the sewage of the proposed project during both wet and dry weather conditions.

(j) Costs. A discussion of the estimated capital costs and where an entire sewerage system is being installed, the estimated annual cost to the user of the system.

(k) Basis of design. The following data shall be provided for the proposed project:

1. Design period.

2. Population densities per acre and total population served.

3. Area served by proposed sewers in acres.

4. Per capita sewage contribution expressed as an average and maximum value, include basis for this determination.

5. Infiltration.

6. Industrial waste contribution.

7. Design flow rates as expressed as average and maximum values.

8. Size of pipe, grade, velocity and maximum capacity.

(L) Environmental analysis. The department may require the submittal of an environmental analysis meeting the requirements of s. NR 110.09 (3) for large or complex sewer projects, for those projects which are proposed to be constructed in environmentally sensitive areas, or for projects which involve significant public controversy.

(2)   Staging of interceptors.

(a) Since the location and length of interceptors will influence growth, interceptor routes and staging of construction shall be planned carefully and shall be consistent with approved areawide waste treatment management plans, growth management plans and other environmental laws.

(b) The staging period for interceptor construction and interceptor pipe sizes shall be cost-effective. A 20 year staging period shall be analyzed. Other staging periods, not to exceed 40 years, may also be evaluated. The cost-effectiveness analysis shall consider the following factors:

1. Cost.

a. Capital cost (present and future).

b. Operation and maintenance cost.

c. Salvage value.

2. Primary environmental impacts.

a. Short-term disruption of traffic, business and other activities.

b. Destruction of flora and fauna.

c. Noise, erosion and sedimentation.

d. Destruction of, or impact on, wetlands and floodplains.

3. Secondary impacts.

a. Pressure to rezone or otherwise stimulate unplanned development.

b. Pressure to accelerate growth for quicker recovery of the nonfederal share of the interceptor investments.

c. Effects on air quality and environmentally sensitive areas by cultural changes.

4. Other nonmonetary impacts including implementation capability, operability, performance reliability and flexibility.

(c) The estimation of peak flows in interceptors shall be based upon the following considerations:

1. Daily and seasonal variations of pipe flows, the timing of flows from the various parts of the tributary area and pipe storage effects.

2. The feasibility of off-pipe storage to reduce peak flows.

3. The use of an appropriate peak flow factor that decreases as the average daily flow to be conveyed increases.

(3)   Construction plans and specifications for sewer projects. In addition to the requirements of ch. NR 108 and ss. NR 110.06 and 110.07 plans and specifications for proposed sewer projects shall include a plan and profile view of all proposed construction. The plans and profiles shall show:

(a) Location. The location of existing or proposed streets and sewers;

(b) Streams and water surfaces. The location and 100 year flood elevation of all streams and water surfaces relevant to the project;

(c) Elevations. The line of the ground surface, the invert and surface elevation at each manhole and the grade of the sewer between each adjacent manhole. Basement elevations shall be noted on the plans or the designing engineer shall state that all sewers are sufficiently deep to serve adjacent basements except where otherwise noted on the plans. Where gravity basement drainage to the proposed sewer will not be possible for existing buildings, the buildings' owners shall be so advised prior to construction of the sewers;

(d) Pipe size and material. The pipe size, material, pipe strength and bedding class shall be shown on the plans or in the specifications;

(e) Manhole spacing. The length of sewer between the manholes shall be shown on the plans;

(f) Special features. The locations of all special features including inverted siphons, concrete encasements, elevated sewers, and other features as appropriate;

(g) Existing structures. The location of all known existing structures and utilities which might interfere with the proposed construction, particularly all water mains, gas mains, storm drains, and other pertinent structures;

(h) Special drawings. Special detail drawings made to a scale to clearly show the nature of the design shall be furnished to show the following:

1. Stream crossings with elevations of the stream bed and of normal and extreme high and low water levels;

2. Details of all special sewer joints and cross-sections;

3. Details of all sewer appurtenances such as manholes, lampholes, inspection chambers, inverted siphons and elevated sewers.

(4)   System evaluation and capacity assurance plan. A system evaluation and capacity assurance plan shall include all the following:

(a) An evaluation of those portions of the sewage collection system that may contribute to sewage treatment facility overflows or other noncompliance at a sewage treatment facility, or that are experiencing or contributing to a sanitary sewer overflow caused by excessive infiltration and inflow or a system hydraulic deficiency. The evaluation must provide estimates of peak flows, including the amount from sanitary sewer overflows and sewage treatment facility overflows, provide estimates of the capacity of key system components, identify hydraulic deficiencies, and identify the sources (including private property sources) of infiltration and inflow that contribute to the peak flows associated with sanitary sewer overflow or sewage treatment facility overflow occurrences.

(b) An analysis to identify actions that will eliminate sanitary sewer overflows and sewage treatment facility overflows or abate their occurrence and effects on public health and the environment to the extent technically and economically feasible. The analysis shall consider alternatives such as providing improved operation and maintenance, infiltration and inflow reduction, and removal from all sources, wastewater equalization or storage facilities, sewer and lift station replacement or rehabilitation, the treatment of overflows, peak flow treatment schemes at sewage treatment facilities, expansion of sewage treatment facility capacity, and any other construction of new or modified sewerage system components.

(c) Identification of specific short and long term corrective actions. Schedules for implementation shall be established giving greatest priority to those actions that will protect public health and minimize environmental risk. The department may establish compliance schedules in WPDES permits to implement specific actions identified under this paragraph.

History: Cr. Register, November, 1974, No. 227 , eff. 12-1-74; r. and recr. Register, December, 1978 , No, 276, eff. 1-1-79; r. and recr. (2), Register, February, 1983, No. 326 , eff. 3-1-83; CR 12-027 : r. and recr. (1) (h), cr. (4) Register July 2013 No. 691 , eff. 8-1-13; CR 13-022 : am. (1) (L) Register March 2014 No. 699 , eff. 4-1-14.

Note

When evaluating feasibility of alternatives, the department may consider factors such as technical achievability, the relationship between the control of storm water and the control of infiltration/inflow into the sewage collection system, costs and affordability of implementation, and risks to public health, the environment, and welfare of the community served by the sewage collection system. Microsoft Windows NT 6.1.7601 Service Pack 1 Portions of a system evaluation and capacity analysis plan may include results from an infiltration/inflow analysis or a sewer system evaluation survey under s. NR 110.09 (5) or s. NR 110.09 (6) , respectively. Microsoft Windows NT 6.1.7601 Service Pack 1