All construction of publicly-owned sewerage systems and privately owned domestic sewerage systems discharging to surface waters shall be based upon application of secondary treatment as a minimum. Where application of secondary treatment would not provide for attainment of water quality standards,the facilities plan shall provide for attaining the applicable standards by designing to meet appropriate water quality related effluent limitations. Sewerage systems discharging to the ground water shall comply with the applicable discharge requirements of ch. NR 206
. The alternative of treating combined sewer overflows shall also be considered.
An evaluation to determine the cost-effective means of disposing of treated effluent.
An evaluation of the most cost-effective means of treating, handling, and disposing of sludge. This evaluation shall include at a minimum the following items:
A description of the current sludge treatment, handling and disposal operations including a discussion of current quantities being produced, a description of current sludge quality including a sludge analysis, a description of any problems associated with the existing operations, and a description of industrial contributions that may affect the quantity and quality of sludge;
An analysis of the anticipated quantity and quality of the sludge from the proposed facility;
A brief description of alternative technologies applicable to the proposed facility improvements, such as, thickening, stabilization, dewatering, storage, transportation, and ultimate disposal;
A cost-effectiveness analysis of the feasible alternatives including an assessment of the environmental impacts as specified in sub. (3)
An evaluation of the storage requirements either at the sewage treatment facility or at an offsite location. The evaluation shall include an estimate of the maximum period of time necessary to store sludge, and a description of the location, accessibility, soils, necessary local permits, depth to groundwater, distance to residential homes, type of facility, topography and any other appropriate information. The storage recommendations shall comply with s. NR 110.26 (10)
An estimate of the amount of land required for each alternative shall be made. Land requirements for landfilling of sludge shall be based upon accepted landfill design practices. Department approval in accordance with chs. NR 500
, is required for construction of sludge landfills and prior to disposal of sludge at an existing licensed landfill.
A discussion of the procedures and timing for abandonment of the existing sludge facilities, if appropriate. This shall include, but not be limited to, the types of sludge wastes to be disposed of during abandonment, ultimate disposal location, possible construction scheduling, quantity of wastes, quality of wastes and any special problems associated with the disposal of these wastes; and
A summary describing the selected plan and its anticipated environmental impacts. Those actions necessary for implementing and operating the sludge management plan shall be presented. This shall include, but not be limited to, the estimated sludge treatment and disposal costs, operator time, discussion of applicable federal and state laws, necessary local permits, public participation programs, training of operators and any other actions necessary to provide for an environmentally sound sludge management program.
An adequate assessment of the expected environmental impacts of the alternatives (including sites) in accordance with sub. (3)
. This assessment shall be an integral part of the analysis of alternatives for cost-effectiveness. The assessment shall be revised as necessary to include information developed during subsequent project steps.
An analysis of the most cost-effective design staging and sizing. The staging and sizing of treatment works shall be based upon the following:
1. `Population projections.'
Population projections for facilities planning shall be in conformance with those contained in applicable approved areawide waste treatment management plans and rules adopted pursuant to ss. 16.96
and 281.57 (4) (b)
, Stats. If such projections are not available, the engineer shall project future population growth based on trends in the recent past.
2. `Wastewater flow estimates.'
In determining total average flow for the design of sewerage systems, the flows to be considered include the average daily base flows (ADBF) expected from each of the following: residential sources, commercial sources, institutional sources, and industries the system will serve plus allowances for future industries and nonexcessive infiltration or inflow.
2m. `Estimation methods.'
The estimation of existing and future ADBF from combined residential, commercial, and institutional sources, shall be based upon one of the following methods:
Existing ADBF shall be estimated based upon a fully documented analysis of water use records adjusted for consumption and losses or on records of wastewater flows for extended dry periods less estimated dry weather infiltration. Future flows for the sewerage system design shall be estimated by determining the existing per capita flows, subtracting any projected per capita water conservation flow reduction and multiplying this figure by the future projected population to be served. Seasonal population can be converted to equivalent full-time residents using the following multipliers:
Day-use visitor (0.1-0.2).
Seasonal visitor (0.5-0.8).
The preferred method shall be used wherever water supply records or wastewater flow data exist. Allowances for future increases of per capita flow over time will not be approved.
Where water supply and wastewater flow data are lacking, existing and future ADBF shall be estimated by multiplying a gallon per capita per day (gpcd) allowance not exceeding those in the following table by the estimated total of the existing and future resident populations to be served. The tabulated ADBF allowances include estimates for commercial and institutional sources as well as residential sources. The department may approve exceptions to the tabulated allowances where large commercial and institutional flows (more than 25% of total estimated ADBF) are documented.
- See PDF for table
The sewerage system total design flow capacity may include allowances for industrial flows. The allowances may include capacity needed for industrial flows which the existing sewerage system presently serves. However, these flows shall be carefully reviewed and means of reducing them shall be considered. Capacity needs for existing flows from industrial users and for future flows from all industries intending to increase their flows or relocate in the area must be documented.
While many uncertainties accompany forecasting future industrial flows, there is still a need to allow for some unforeseeable future industrial growth. Thus, design capacity of the treatment works may include (in addition to the existing industrial flows and future documented industrial flows) a nominal flow allowance for future nonidentifiable industries or for unplanned industrial expansions, provided that areawide waste treatment management plans, land-use plans and zoning provide for the industrial growth. This additional allowance for future unplanned industrial flow may not normally exceed 5%, or 10% for towns with less than 10,000 population, of the total average design flow of the treatment works exclusive of the allowance or 25% of the total industrial flow, existing plus documented future, whichever is greater.
4. `Staging of sewage treatment facilities.'
For municipally owned projects the design capacity of new, upgraded or expanded sewage treatment facilities shall not exceed that necessary for wastewater flows projected during the initial staging period. Privately owned domestic waste treatment facilities shall provide design capacity for estimated flows 20 years from the estimated time of start-up of the facilities unless the cost-effectiveness staging analysis is done to justify a lesser design staging period. The staging period for municipally owned waste treatment facilities shall be determined by either of the following methods:
The owner shall analyze at least 3 alternative staging periods (10 years, 15 years and 20 years) and the least costly (i.e., total present worth or average annual cost) staging period shall be selected.
The staging period may not exceed the period which is appropriate according to the following table.
A municipality may stage the construction of a treatment plant for a shorter period than the maximum allowed under this subdivision. A shorter staging period might be based upon environmental factors (secondary impacts, compliance with other environmental laws, energy conservation, water supply), an objective concerning planned modular construction, the utilization of temporary treatment plants, or attainment of consistency with locally adopted plans including comprehensive and capital improvement plans. However, the staging period may in no case be less than 10 years, because of associated cost penalties and the time necessary to plan and construct later stages.
An evaluation of the costs, cost-savings, and effects of flow reduction measures unless the existing average daily base flow from the area is less than 70 gpcd, or the current population of the municipality is under 5,000, or the area is exempted by the department for having an effective existing flow reduction program. A flow reduction program shall be adopted by municipalities which shall include those measures determined to be cost effective.
An analysis of innovative and alternative treatment processes and techniques that reclaim and reuse water, productively recycle wastewater constituents, eliminate the discharge of pollutants or recover energy. Where certain categories of alternative technologies may not be generally applicable because of prevailing climatic or geological conditions, a detailed analysis of these categories of alternative technologies is not required. However, the reason for such a rejection must be fully substantiated in the facilities plan.
An analysis of the primary energy requirements (operational energy inputs) for each system considered. The alternative selected shall propose adoption of measures to reduce energy consumption or to increase recovery as long as such measures are cost effective.
A flood analysis for the selected treatment facility site if the site is in, or suspected to be in, a floodplain. The analysis shall meet the requirements of s. NR 116.07
. The analysis shall determine the limits of the floodplain and the floodway, the regional flood elevation, and the effects on floodstage of constructing the sewage treatment facility, including dry land access and flood protection. The flood velocities at the sewage treatment facility site, and the duration of the regional flood shall also be determined. If a dry land access waiver is requested in accordance with s. NR 110.15 (3) (c)
, the flood analysis shall also include the information necessary to support the request.
An assessment of the location of the sewage treatment facilities relative to commercial establishments and to buildings which are occupied or intended for residential use, and from land which is being actively developed for commercial or residential use. The location of sewage treatment facilities shall comply with the provisions of s. NR 110.15 (3) (d)
An assessment of the location of land disposal systems relative to public water supply wells. The location and horizontal separation from the proposed land disposal site and any public water supply well shall be shown. The assessment shall discuss the hydrogeologic conditions of the area, the direction of groundwater movement, the depth of the public well casing, and any other appropriate information. The department will determine whether the separation distance between the land disposal system and the public well is sufficient to protect the public health and quality of the public water supply.
Soil boring logs if the selected treatment alternative includes lagoons or land disposal of effluent. The borings shall supply accurate information about the soil conditions, and groundwater and bedrock elevations at the proposed treatment facility site.
Any facility plan which recommends the abandonment of a wastewater treatment, sludge or septage storage lagoon, or land disposal system shall include an abandonment plan. An abandonment plan outlining the proposed method of abandonment of the facility shall be submitted as part of the facility plan to the department for approval. This abandonment plan shall provide for the removal and proper recycling, treatment or disposal of any accumulated solid matter, solid or liquid wastes or wastes in combination with soil. All recycling, treatment and disposal shall be conducted so as to protect public health and the environment. Unless otherwise directed by the department, all abandonment plans for wastewater treatment, sludge or septage storage lagoons, or high rate land disposal systems shall comply with ch. NR 720
for soils that have been contaminated by the contents of the lagoon or system. The abandonment plan shall address relandscaping necessary to prevent accumulation of standing water or runoff and shall provide for completion of the relandscaping within 2 years of the date on which the structure was last used as it was originally intended. The department shall require groundwater monitoring for a minimum of one year at a quarterly frequency after the abandonment of facilities which have an existing groundwater monitoring system. Groundwater monitoring may be required on a case-by-case basis for facilities which do not have existing groundwater monitoring systems. The monitoring data shall be reviewed after 1 year and the department shall determine whether groundwater monitoring should be continued or not. Any groundwater monitoring wells which are no longer necessary shall be abandoned in accordance with ch. NR 141
and documentation of well abandonment shall be provided to the department.
Content of an environmental analysis.
An adequate environmental analysis must be an integral, though identifiable, part of any facilities plan submitted to the department under sub. (1)
. The analyses that constitute an adequate environmental analysis shall include:
(a) Description of the existing environment without the project.
This shall include for the delineated planning area a description of the present environmental conditions relevant to the analysis of alternatives or determinations of the environmental impacts of the proposed action. This description shall include, but not be limited to, discussions of the following topics where applicable to a particular study: surface and ground water quality; water supply and use; general hydrology; air quality; noise levels; energy production and consumption; land use trends; population projections, wetlands, floodplains, coastal zones and other environmentally sensitive areas; historic and archaeological sites; other related federal or state projects in the area; and plant and animal communities which may be affected, especially those containing threatened or endangered species.
(b) Description of the future environment without the project.
The future environmental conditions with the no project alternative shall be forecast, covering the same areas listed in par. (a)
(c) Evaluation of alternatives.
This discussion shall include a comparative analysis of feasible options and a systematic development of wastewater treatment alternatives. The alternatives shall be screened with respect to capital and operating costs; significant primary and secondary environmental effects; physical, legal or institutional constraints; and whether or not they meet regulatory requirements. Special and induced impacts such as development. The reasons for rejecting any alternatives shall be presented in addition to any significant environmental benefits precluded by rejection of an alternative. The analysis should consider, when relevant to the project:
Flow and waste reduction measures, including infiltration/inflow reduction;
Alternative locations, capacities, and construction phasing of facilities;
Alternative waste management techniques, including treatment and discharge, wastewater reuse and land application;
Alternative methods for disposal of sludge and other residual waste, including process options and final disposal options;
Improving effluent quality through more efficient operation and maintenance;
(d) Environmental impacts of the proposed action.
Primary and secondary impacts of the proposed action shall be described, giving special attention to unavoidable impacts, steps to mitigate adverse impacts, any irreversible or irretrievable commitments of resources to the project and the relationship between local short term uses of the environment and the maintenance and enhancement of long term productivity. The significance of land use impacts shall be evaluated, based on current population of the planning area; design year population for the service area; percentage of the service area currently vacant; and plans for staging facilities. Special attention should be given to induced changes in population patterns and growth, particularly if a project involves some degree of regionalization.
(e) Steps to minimize adverse effects.
This section shall describe structural and nonstructural measures, if any, in the facilities plan to mitigate or eliminate significant adverse effects on the human and natural environments. Structural provisions include but are not limited to changes in facility design, size, and location; nonstructural provisions include but are not limited to staging facilities as well as developing and enforcing land use regulations and environmentally protective regulations.
Sources of information used to describe the existing environment and to assess future environmental impacts should be documented. In addition to the department, these sources should include regional, state and federal agencies with responsibility or interest in the types of impacts listed in par. (a)
. In particular, the following agencies should be consulted:
Local, and regional land use planning agencies and areawide waste treatment management planning agencies for assessments of land use trends and population projections, especially those affecting size, timing, and location of facilities;
The HUD regional office if a project involves a flood risk area identified under the Flood Disaster Protection Act of 1973 (Pub.
The state coastal zone management agency, if a coastal zone is affected;
The secretary of the interior or secretary of agriculture, if a wild and scenic river is affected;
The secretary of the interior or secretary of commerce, if a threatened or endangered species is affected;
The fish and wildlife service (department of the interior), the department of commerce, and the U.S. army corps of engineers, if a wetland is affected.
Municipalities shall hold at least one public hearing before a facilities plan is adopted. A copy of the facilities plan should be available for public review before the hearing and at the hearing, since these hearings provide an opportunity for public comment on the issues associated with the facilities plan.
Content of an infiltration/inflow analysis. NR 110.09(5)(a)
The infiltration/inflow analysis shall demonstrate whether or not excess infiltration/inflow exists in the sewer system. The analysis shall identify the presence, flow rate, and type of infiltration/inflow conditions, which exist in the sewer systems.
For determination of the possible existence of excessive infiltration/inflow, the analysis shall include an estimate of the cost of eliminating the infiltration/inflow conditions. These costs shall be compared with estimated total costs for transportation and treatment of the infiltration/inflow. This determination shall be made at several levels of infiltration/inflow removal.
If the infiltration/inflow analysis demonstrates the existence or possible existence of excessive infiltration/inflow and the specific sources of excessive infiltration/inflow have not been adequately identified, a sewer system evaluation survey shall be conducted in accordance with sub. (6)
. A detailed plan for the sewer system evaluation survey shall be included in the infiltration/inflow analysis. The plan shall outline the tasks to be performed in the survey and their estimated costs.
The department may waive the requirements of pars. (a)
if the owner can demonstrate to the department's satisfaction the obvious existence or nonexistence of excessive infiltration or inflow, or both. The information necessary for this demonstration may include infiltration and inflow estimates, per capita design flows, ratio of total flow to dry weather flow, cubic meters of infiltration per centimeter diameter per kilometer of pipe per day (gallons of infiltration per inch diameter per mile per day), bypassing, and other hydrological and geological factors. The department may require the information be expanded to meet the requirements of pars. (a)
if this demonstration is inconclusive.
Content of a sewer system evaluation survey. NR 110.09(6)(a)
The sewer system evaluation survey shall determine the location, estimated flow rate, method of rehabilitation and cost of rehabilitation versus cost of transportation and treatment for each defined source of infiltration/inflow.
The report shall summarize the results of the sewer system evaluation survey. In addition, the report shall include:
A justification for each sewer section cleaned and internally inspected; and
A proposed rehabilitation program for the sewer system to eliminate all defined excessive infiltration/inflow.
Construction plans and specifications for sewage treatment plant projects.
In addition to the requirements of ch. NR 108
and ss. NR 110.06
, the following requirements shall be adhered to for submission of plans for sewage treatment plants.
(a) Overall plan.
A plan shall be submitted which shows the sewage treatment plant in relation to the remainder of the system. Sufficient topographic features shall be included to indicate its location with respect to streams and the point of discharge of treated effluent.
A general layout plan shall be submitted which includes:
Piping details including piping arrangements for bypassing individual units;
The materials handled and the direction of flow through each pipe;
(c) Detailed plans.
Detailed construction plans shall be submitted which include:
The location, dimensions, elevations and details of all existing and proposed plant units;
The elevation of high and low water level in the receiving stream;
An adequate description of all features not covered in the specifications.
Additional facility planning requirements for land disposal system alternatives. NR 110.09(8)(a)
(a) General requirements.
In addition to the requirements of sub. (1)
, a report including a soil investigation and a hydrogeologic evaluation shall be submitted as part of the facilities plan for a land disposal discharge alternative. The report shall detail the soil types, characteristics, variability and permeability, topography, groundwater conditions and quality, and other characteristics of the disposal site. Soil boring and test pit logs and soil analyses shall be provided. Wastewater characteristics which may influence the design of the disposal system shall also be discussed. Water supply quality, local groundwater use, and potential impacts of the facility on groundwater quality shall be included.
A hydrogeological investigation shall be included as part of the facilities plan. The analysis of the hydrogeological information shall be done by a hydrogeologist, or other qualified person. The investigation shall include both regional and site-specific hydrogeological information.
NR 110.09 Note
Note: The skills and knowledge required of a hydrogeologist making submittals under this chapter include: the ability to apply hydrogeologic principles and practices to the siting, design and operation of land disposal systems; knowledge of contaminants associated with land disposal of wastewater, their transport mechanisms and fate in the environment; familiarity standards; and proficiency in the design of groundwater monitoring systems for defining the physical and chemical characteristics of groundwater flow. A soil scientist or other environmental scientist who can demonstrate the above skills and knowledge, as reflected in submittals made under this chapter, shall be deemed a “qualified person".
The following site-specific groundwater information may be required as part of the facilities plan for land disposal facilities: