Facility Plan Guidance for Wastewater Treatment Facilities - PUB2416

This document provides engineering consultants a reference guide of requirements and recommendations for an approvable facility plan for wastewater treatment facility construction projects. Review Code of State Regulations 10 CSR 20-6.010(4)(B) for a list of projects that are exempt from submitting facility plans. Projects receiving funding under 10 CSR 20-4 refer to Wastewater Financial Opportunities, Clean Water State Revolving Fund Project Facility Plan Guidance - PUB2418 and 10 CSR 20-4.

The purpose of a facility plan is to identify and evaluate treatment needs at a facility, make the best use of limited funding and ensure the client (i.e., the permittee) can make an informed decision. Facility planning leads to greater efficiency and cost-savings by providing a logical evaluation of available options and possible alternatives to address the facility’s current and future needs. Department review of a facility plan before detailed design leads to a smoother and faster construction permitting process and fewer design revisions.

Each facility plan must obtain Department agreement before design and construction permit application, plans and specifications, summary of design and associated fee(s) submittal. Look at 10 CSR 20-6.010(4) and 10 CSR 20-8.110(2)(A) for more information. Submitting a facility plan does not remove any compliance requirements specified in the Missouri State Operating Permit or through an enforcement agreement.

You may submit a facility plan for review by using the Facility Plan or Engineering Report Review Request MO 780-2617 form. Facility plans must be prepared, signed, sealed and dated by a professional engineer registered in Missouri, 10 CSR 20-6.010(4)(A)1 and 10 CSR 20-8.110(2). Provide an electronic version, as a searchable pdf, by email to DNR.WPPEngineerSection@dnr.mo.gov (up to 10 MB file size), on a compact disc or USB drive, or provide a link to the consultant’s cloud-based shared drive. 

Facility plan requirements are provided in Section 1.3 of the Wastewater Guidelines and Standards Document - PUB2754, 10 CSR 20-6.010(4) and 10 CSR 20-8.110(5). The level of detail required in a facility plan varies according to the size, scope and complexity of the proposal. Include enough detail to demonstrate the proposed project addresses the needs of the facility, meets the minimum design standards in 10 CSR 20-8 and meets all other applicable requirements.

Projects to construct a new discharge or to increase a facility design flow require a Water Quality and Antidegradation review. Complete the review before the facility plan to ensure the facility plan evaluates solutions that provide appropriate treatment. Review the Missouri Antidegradation Implementation Procedure, 10 CSR 20-6.010(3) and (4)(A)5.A. and 10 CSR 20-7.031(3) for additional information. 

Basic Outline of a Facility Plan

 See 10 CSR 20-8.110 and Section 1.3 of the Wastewater Guidelines and Standards Document - PUB2754 for requirements and recommendations. 

• Cover page with all facility and contact information [10 CSR 20-8.110 (4)(A) and (5)]
• Table of Contents
• Identify and evaluate wastewater treatment facility challenge(s), such as a compliance schedule, an increase in flow or pollutant load or effluent limit violations [10 CSR 20-8.110 (4)(B)]
• Assemble basic information
  • Planning and service area location [10 CSR 20-8.110 (5)(A)]
  • Population projection and planning period (20 years) [10 CSR 20-8.110 (5)(B)]
  • Hydraulic Capacity and Organic Waste Load [10 CSR 20-8.110 (3) & (5)(C)]
• Examine alternatives, including initial development and evaluations [10 CSR 20-8.110 (5) (D) & (E)]
  • Alternatives must include a no-discharge option and a regionalization option [10 CSR 20-8.110 (5)(E)3.- 4. and 10 CSR 20-6.010(4)(A)5.B. - C.]
  • Provide sufficient information to document the reason an alternative is not feasible.
  • Include the information outlined in 10 CSR 20-8.200(2) when the project includes wastewater irrigation or subsurface soil dispersal [10 CSR 20-8.110(5)(E)5. and 10 CSR 20-6.010(4)(A)5.D.]
• Detailed site evaluation [10 CSR 20-8.110(5)(E)6.)
  • Include a completed geohydrologic evaluation for earthen basins and irrigation [10 CSR 20-6.010(4)(A)5.D., 10 CSR 20-8.110(5)(E)6.G. and 10 CSR 20-8.200(2)(B)]
  • Include a discussion of soils and a soil morphology analysis as needed. [10 CSR 20-8.110(5)(E)6.I.-J. and (7) and 10 CSR 20-8.200(2)(C)]
• Design criteria and assumptions [10 CSR 20-8.110(5)(E)7.]
• Maps, diagrams and preliminary layouts [10 CSR 20-8.110(5)(E)8.-9.]
• Preliminary cost estimates for all alternatives (20-year present worth of capital construction costs and annual operation and maintenance costs) with enough detail to make an informed decision [10 CSR 20-8.110(5)(E)16.]
• Recommended project alternative [10 CSR 20-8.110(5)(F)]
  • Present the recommended project from the alternatives considered.
  • Include financing considerations.
  • Outline expected project schedule, including any enforcement or permitting schedules of compliance dates.

Special Considerations and Often Missed Requirements

• Ensure there is a valid continuing authority that owns, operates or has area-wide management authority, such as a municipality, sewer district or person (as defined by 644.016(15), RSMo) actively registered with the Missouri Secretary of State Business Entity Search. [10 CSR 20-6.010(2)]
• Consider how the project affects environmental justice, affordability and underrepresented populations when discussing the planning and service area.
• Provide engineering criteria and assumptions used in the preliminary design for each alternative. Provide the basis for unit operation and preliminary unit process sizing. Discuss hydraulic and organic loadings (design average and design peak hour), flow rates and velocities, detention times, concentrations, recycle flows and locations, chemical additive control, physical controls and flow metering, removal efficiencies, effluent concentrations, energy requirements and flexibility, as needed. 
• Existing wastewater treatment facilities - Provide a detailed description of each process unit to remain, taking into account the age and condition of each unit. Include a plan for the method and level of treatment during construction (including solids processing, storage and disposal) and the general plan for maintaining compliance with effluent limitations and the facility’s Missouri State Operating Permit. [10 CSR 20-8.110(5)(E)15., (9)(A)5. and (10)(C)] 
• Include a brief inventory of any existing collection system, especially regarding how any inflow or infiltration will affect the wastewater treatment facility .
• For new systems - Identify the source used to establish design flows. (Table 1-1 of the Wastewater Guidelines and Standards Document - PUB2754, Department of Health or other technical manual) [10 CSR 20-6.010(4)(A)2.]
• Provide justification when regionalization is not feasible. [10 CSR 20-6.010(2)(C)]
• Submit sufficient documentation to justify if a non-discharging option is not feasible.
• Provide a completed geohydrologic evaluation for projects involving a new wastewater treatment facility, new or relocated outfall, new or major modification to an earthen basin and new permit features (e.g., wastewater irrigation sites, subsurface soil absorption or dispersal sites). The geohydrologic evaluation from the Missouri Geologic Survey is a free service through the Geologic Evaluation Data Gateway Exchange (GeoEDGE). This may take some time, so request this early.
• Comment on how geologic information may affect the project (e.g., drinking water wells, sinkholes, losing streams). Consult the department's Geosciences Technical Resource Assessment Tool (GeoSTRAT) GIS web application for a quick reference to readily available geologic and geotechnical data. The minimum distance between a wastewater treatment facility and any potable water source must be at least 300 feet. The minimum distance between sewers and any existing or proposed public water supply well or other water supply sources or structures must be at least 50 feet, according to 10 CSR 20-8.120(5)(B) and 10 CSR 23-3.010.  
• Submit a soil morphology analysis conducted by a qualified soil scientist or engineer for all subsurface soil systems and surface irrigation systems applying over 24 inches per year. Soils reports must comply with 10 CSR 20-8.110(7). Discuss the soil’s long-term hydraulic acceptance rate, any limiting layers (e.g., depth to bedrock, restrictive horizons, seasonal high water table) and how the minimum vertical separation will be obtained. Refer to 10 CSR 20-8.110(5)(E)6.J., 10 CSR 20-8.110(7) and 10 CSR 20-8.200 (2)(C), (7), (8) and (9). It is recommended that the soil scientist fill out the Summary of Soils Report for Land Application of Treated Wastewater MO 780-2696 for any submitted soils report.
• The land area that is normally wetted by wastewater application must be located outside of flood-prone areas having a flood frequency greater than once every 10 years. [10 CSR 20-8.200(6)(B)]
• Non-discharging lagoon system designs must include the 10-year rainfall minus evaporation for the selected design period and the existing sludge volume. Review No-discharge Alternative Evaluation - PUB2665, Conversion to a No-Discharge Irrigation System from a Discharging Lagoon System - PUB2669 and Wastewater Irrigation - Frequently Asked Questions - PUB2668.
• Discuss flood protection. Protect facility structures and both electrical and mechanical equipment from physical damage during a 100-year flood. Visit the Federal Emergency Management Agency's Flood Map Service Center for flood hazard information. [10 CSR 20-8.110(5)(E)6.E. and 10 CSR 20-8.140(2)(B)]
• Documents all require separation distances. [10 CSR 20-8.110(5)(E)6.A. and 10 CSR 20-8.140(2)(C)] Additional setback distances are listed in 10 CSR 20-8.200(6)(B) and 10 CSR 20-8.300(4).
• Identify all regionalization opportunities. The Missouri Accessible Permitting Information Tool (MAPiT) provides information related to wastewater permitting and can help discover possible regionalization opportunities.
• Discuss emergency operation measures as outlined in 10 CSR 20-8.130 and 10 CSR 20-8.140, including alternate sources of electric power or pumping capability to allow continuing operation during power, equipment or infrastructure failures (e.g., pipe breaks).
• Clearly identify new or innovative technology, if proposed. Provide a contingency plan in the event that such new or innovative technology fails to meet the expected performance. Review 644.051.12,, RSMo, Innovative Technologies and Approval Process for Innovative Technology - PUB2453. [10 CSR 20-8.110 (5)(E)12. and (6)]
• Provide a discussion of nutrient removal capabilities and similar issues, including the footprint available for expansion or treatment facility modifications necessary for nutrient removal. [10 CSR 20-8.110(5)(E)6.D. & 13., 10 CSR 20-8.140(2)(C)3. and 
• 10 CSR 20-8.200(2)]
• Include any changes or impacts to operations and maintenance costs, special equipment and operator certification. Review Appendix 2: Operation and Maintenance Manual of the Wastewater Guidelines and Standards Document - PUB2754. 
• If the proposal includes closing an existing wastewater treatment facility or part of an existing facility, submit a closure plan to the appropriate regional office for review and approval. For more information on closure plans and their requirements, review Standard Conditions Part III of the current Missouri State Operating Permit, Wastewater Treatment Plant Closure - PUB2568 and Facility Closure Request Form MO 780-2512.