FINAL_OCDPW_Pump Station Design Manual_2025-06-30.pdf

Ontario County Department of Public Works

Pump Station Design Manual June 2025 i

Ontario County Pump Station Design Manual

Prepared By: Prepared For:

Arcadis of New York, Inc. Mr. Timothy G. McElligott, PE 100 Chestnut Street, Suite 1020 Deputy Commissioner Rochester, NY 14604 Ontario County Department of Public Works United States 2962 County Road 48 Phone: 585 385 0090 Canandaigua, NY 14424 Fax: 585 546 1973

Our Ref:

30229712 / 02095027 ii

Contents Acronyms and Abbreviations ................................................................................................................................ vi Executive Summary........................................................................................................................................... ES-1 1 General

1.1 Applicability

1.2 Organization of Manual

1.3 Design Standards

1.4 Application Submittal Requirements

1.5 Project Procedures

1.5.1 30% Preliminary Design

1.5.2 60% Design

1.5.3 90% Design

1.5.4 Construction Documents

1.6 Agencies, Codes and Permits

1.6.1 Permits

1.6.2 Property Acquisitions and Easements

1.6.3 State Environmental Quality Review Act

1.6.4 State Historic Preservation Office Review

1.6.5 Utility Coordination

2 Pump Design and Operating Criteria

2.1 Wastewater Characteristics

2.2 Allowable Pump Station and Pumping Equipment Types

2.3 Design Flow Criteria

2.3.1 Service Area Definition

2.3.2 Design Flow Development

Average Daily Wastewater Flow Rate Peak Hourly Wastewater Flow Rate Alternative Design Flows

2.4 Hydraulic Analysis and Pump Selection

2.4.1 Pumps

2.4.2 Force Main

2.4.3 Wet Well

2.5 Downstream Capacity

iii

3 Civil and Mechanical Criteria

3.1 Property Ownership Requirements

3.2 Site Development Requirements

3.2.1 Floodplain

3.2.2 Setback and Buffers

3.2.3 Access Roads/Driveways

3.2.4 Water Service

3.2.5 Site Layout

3.2.6 Architecture and Landscape

3.2.7 Odor Control

3.2.8 Site Security and Fencing

3.3 Wet Well Requirements

3.3.1 General Requirements

3.3.2 Submersible Pump Stations

3.3.3 Wet/Dry Pit Stations

3.3.4 Design Criteria

3.3.5 Testing

3.4 Pump, Piping, and Valve Requirements

3.4.1 Process Pumps

3.4.2 Sump Pumps

3.4.3 Piping

3.4.4 Valves

3.4.5 Valve and Flow Meter Vaults

3.4.6 Bypass

3.5 Ancillary Equipment and Pump Station Accessories

3.5.1 Flow Metering Requirements

3.5.2 Ventilation and Noise Control

3.5.3 Access

3.5.4 Interior Lighting

3.5.5 Hatches

3.5.6 Equipment Removal Provisions

Hoists Pump Guide Rail System iv

4 Force Main Criteria

4.1 General

4.2 Pipe Materials

4.2.1 Ductile Iron

Internal Lining Requirements External Coating Requirements

4.2.2 HDPE

Pipe and Fittings Heat Fusion of Pipe Joints

4.3 Thrust Blocks

4.4 Tracer Wire and Location Stations

4.5 Diameter

4.6 Air-Release/Vacuum Valve Installations

4.7 Force Main Discharge and Receiving Manholes

4.8 Right-of-Way Requirements

5 Electrical, Instrumentation and Control Criteria

5.1 General Conditions

5.2 Hazardous Classification Areas

5.3 Electrical Labeling

5.4 Power Requirements

5.4.1 Sizing

5.4.2 Selection

5.4.3 Equipment Requirements

5.4.4 Standby Power

5.5 Grounding

5.5.1 System Grounding

5.5.2 Equipment Grounding

5.5.3 Instrumentation Grounding

5.6 Instrumentation and Controls (I&C)

5.6.1 Control Philosophy

5.6.2 PLC-Driven Pump

5.6.3 Pump Operation

5.6.4 Indicator Lights

5.6.5 Control Devices

5.6.6 Commissioning of Pump Station System

v

5.7 Power System Studies

6 Quality Assurance and Quality Control

6.1 Preconstruction Meeting

6.1.1 Preparation

6.1.2 Submittals Required Prior to Meeting

6.1.3 Required Attendees

6.1.4 Agenda

6.2 Inspection by County Staff, Department of Public Works, Bureau of Wastewater Management . 36

6.2.1 Activities Requiring Inspection and Observation

6.2.2 Documentation and Reporting

6.2.3 Non-Compliance and Corrective Actions

6.2.4 Final Inspection and Acceptance

6.3 Project Closeout

6.3.1 Substantial Completion

6.3.2 Final Payment Obligations

Appendices Appendix A - Minimum Codes and Standards List

Appendix B - Basis of Design Engineering Report Outline

Appendix C - Subsurface Exploration and Geotechnical Report Requirements

Appendix D - Design Submittal Requirements and Checklists

Appendix E - Example Drawing List

Appendix F - Ontario County Equipment Manufacturer and Materials Lists

Appendix G - Pump Station Configuration Decision Matrix

Appendix H - Certificate of Substantial Completion

Appendix I - Final Payment Obligations vi

Acronyms and Abbreviations AASHTO Association of State Highway Transportation Officials

AOR Allowable Operating Range

ASTM American Society for Testing and Materials

AWWA American Water Works Association

BWM Bureau of Wastewater Management

CLCSD Canandaigua Lake County Sewer District

CRIS Cultural Resource Information System

DI Ductile Iron

DIP Ductile Iron Pipe

EFC Environmental Facilities Corporation

EDUs Equivalent Dwelling Units

FEMA Federal Emergency Management Agency

FPS Feet Per Second

GPM Gallons per minute

HDPE High-Density Polyethylene

HI Hydraulic Institute

HLCCSD Honeoye Lake County Consolidated Sewer District

HOA Hand-Off-Auto

IEEE Institute of Electrical and Electronics Engineers

MCCs Motor Control Centers

NEC National Electric Code

NEMA National Electrical Manufacturers Association

NFPA National Fire Protection Association

NPSH Net pressure suction head

NRHP National Register of Historic Places

NTP Notice to Proceed

NYCRR New York Codes, Rules and Regulations

NYSBC New York State Building Code

NYSEC New York State Energy Code

OCDPW Ontario County Department of Public Works

OSHA Occupational Safety and Health Administration vii

P&ID Process and Instrumentation Diagram

PLC Programmable Logic Controllers

PS Pump Station

PVC Polyvinyl Chloride

QC Quality Control

ROW Rights-of-Way

SCADA Supervisory Control and Data Acquisition

SEQR State Environmental Quality Review Act

SHPO State Historic Preservation Office

Standards Ontario County’s Pump Station Design Standards

TDH Total Dynamic Head

TR-16 Guides for the Design of Wastewater Treatment Works

VFDs Variable Frequency Drives

ES-1

Executive Summary County of Ontario Local Law 5-1999 created the Bureau of Wastewater Management and designated its administrative head to be the Commissioner of Public Works, hereinafter referred to as “the Commissioner”. The Bureau of Wastewater Management is responsible for the maintenance and repair of all sewer facilities owned and operated by Ontario County which encompass the Canandaigua Lake County Sewer District (CLCSD), Route 332 Extension of CLCSD and Honeoye Lake County Consolidated Sewer District (HLCCSD).

CLCSD was established in 1974 and encompasses portions of the towns of Canandaigua, Gorham and Hopewell and is approximately 9.1± square miles (mi2) in size. CLCSD operates and maintains wastewater collection, pumping, and metering facilities in the district and Ontario County has a Municipal Cooperation Agreement with the city of Canandaigua for the treatment and conveyance of wastewater for all of CLCSD and any extensions thereof.

Route 332 Extension of CLCSD was established in 1988 and encompasses portions of the town of Canandaigua and is approximately 1.2± mi2 in size. Route 332 Extension of CLCSD operates and maintains wastewater collection and pumping facilities in the district and Ontario County has a Municipal Cooperation Agreement with the city of Canandaigua for the treatment and conveyance of wastewater from said district.

HLCCSD was established in 1975, and Extension No. 1 Honeoye Lake County Sewer District was established in 1976. HLCCSD and Extension No.1 were consolidated in 1990. HLCCSD encompasses portions of the towns of Canadice and Richmond and is approximately 2.1± mi2 in size. HLCCSD operates and maintains wastewater collection, pumping, and wastewater treatment facilities in the district.

The purpose of this manual is to establish the Ontario County’s Pump Station Design Standards (Standards) for the Ontario County Bureau of Wastewater Management, hereinafter referred to as “the County”. These Standards have been developed to provide continuous and uninterrupted sewer service to protect public health and the environment, reduce the risk of wastewater collection system failures and backups, and minimize the operations and maintenance cost of the County’s pump stations. This manual presents contemporary design considerations for newly constructed pump stations owned and operated by the County. This manual does not replace or supersede any codes, standards, or local, State, or Federal rules and regulations. It is to be used in conjunction with, not in lieu of, relevant codes and standards. The Standards cover pump station capacity requirements and configuration, the selection and design of pumping equipment, piping system layout and hydraulic considerations, electrical and instrumentation systems design, and other pump station appurtenances.

While this manual presents relevant information and design standards for newly constructed pump stations to become owned and operated by the County, it is not intended to serve as a formal basis of design for such stations, nor shall it be interpreted as such. This manual is neither a master document on pump station design, nor is it meant to provide a “cut and paste” approach to such design. This document is intended to be used by the practicing design professional. As such, it focuses on current design standards and practices for individuals that have a general understanding and knowledge of the basic principles of pump station design. It shall be the sole responsibility of the pump station designer and engineer of record to follow all laws, regulations, and codes. The designer will be expected to prepare and seal all necessary design calculations, reports, drawings, and specifications for each site. These Standards shall apply to all projects where the County shall become the Owner of newly constructed pump stations.

1 General This section defines the applicability and organization of the manual along with design standards and procedures.

1.1 Applicability

Pump stations will only be allowed for developments greater than or equal to 100 equivalent dwelling units (EDUs) which cannot feasibly be served by an existing gravity sanitary sewer. All other developments shall be served by gravity sewer. The Commissioner reserves the right to request pertinent studies and impose additional requirements deemed necessary for the public interest. Additionally, the requirements set forth in this manual are subject to the review and approval of the Commissioner, and subject to the requirements of all applicable codes, ordinances and laws.

This manual shall not apply to existing pump stations currently owned and operated by the County.

1.2 Organization of Manual

This design manual is separated into six sections as follows:

1. General

2. Pump Design and Operating Criteria

3. Civil and Mechanical Criteria

4. Force Main Criteria

5. Electrical, Instrumentation and Control Criteria

6. Quality Assurance and Quality Control

1.3 Design Standards

The design professional shall comply with all relevant codes and standards, including but not limited to:

• Recommended Standards for Wastewater Facilities, Policies for the Design, Review, and Approval of Plans and Specifications for Wastewater Collection and Treatment Facilities (Ten States Standards)

• Guides for the Design of Wastewater Treatment Works (TR-16)

• National Electric Code (NEC)

• National Fire Protection Association (NFPA)

• New York State Building Code (NYSBC)

• New York State Energy Code (NYSEC)

• Other local codes, ordinances, and regulations

Where a conflict arises between the Standards described herein and other relevant standards, codes, laws, and/or regulations, the more stringent requirement as determined by the County shall apply. The County cannot waive any requirements set forth by the State or Federal Government. The design professional shall clearly identify all elements of their design that do not meet these minimum design standards and requirements.

Refer to Appendix A Minimum Codes and Standards List.

1.4 Application Submittal Requirements

The design submittal process shall proceed as follows:

1. The design professional, on behalf of the project sponsor, shall notify the County’s Department of Public Works (OCDPW) Deputy Commissioner and Supervisor of the Bureau of Wastewater Management regarding their intent to construct a new wastewater pumping station. The notification is to include a summary with the following minimum information:

a. Project sponsor’s contact information

b. Discussion of available downstream capacity

c. Description of Offsite Public Sewer Improvements and/or Connections.

d. Volume of Wastewater Generated by this Project.

e. Estimated Peaking Factor

f. Existing Downstream Sanitary Sewer Diameter.

g. Facility ID of Receiving Manhole.

2. A meeting will then be held with County staff to discuss information presented in notification. No subsequent phase of the project shall progress without the written approval of the County.

3. The County will evaluate the information received. Once the information is agreed upon, a Preliminary Design Phase Notice-to-Proceed (NTP) will be issued by the County.

4. After County’s issuance of the Preliminary Design Phase (PDP) NTP, the design professional shall submit the 30% preliminary design deliverable in accordance with the following Project Procedures. A minimum of 30-days shall be provided to the County to review and provide comments on design deliverable.

5. Once the 30% preliminary design is considered complete by the County, a Detailed Design Phase (DDP) NTP will be issued by the County and the design professional shall commence the 60% design deliverable and then a 90% design deliverable in accordance with the following Project Procedures. A minimum of 30-days shall be provided to the County to review and provide comments on each design deliverable. The 90% design deliverable shall include draft property acquisition documents, suitable for filing at County Clerk’s office and Contract Documents signed and sealed by a licensed professional in the State of New York. The 90% design deliverable shall be used to begin the permit review process with all permitting agencies.

6. Once the 90% design deliverable is considered complete by the County, the final Contract Documents shall be signed and sealed by a licensed professional engineer in the State of New York. The final property acquisition documents, suitable for filing at County Clerk’s office, shall accompany the final Contract Documents and shall be signed and sealed by a licensed professional surveyor in the State of New York. After County’s review and approval of the final Contract Documents, property acquisition documents, and copies of all permitting agencies approvals, the County will issue the Construction Phase Authorization (CPA) NTP.

7. Upon receipt of the CPA, the project sponsor may bid the pump station using the approved final Contract Documents.

8. Construction may not proceed until the County issues the Sewer Extension Permit and all of the following documents are provided to the County:

a. Sewer District Extension Map, Plan & Report (if not already in an established district extension);

b. Copies of all required agency permits (NYS DEC, NYS DOH, building, highway work, environmental, etc.)

c. Letter of Credit;

d. Plans & Specifications, including any addenda;

e. Copies of all property acquisitions and easements filed at County Clerk’s office;

f. Approved shop drawings;

g. Contractor’s proof of insurance per County requirements;

h. Contractor’s site-specific Health and Safety Plan;

i. List of all utility accounts;

j. Special Contracts/Agreements; and

k. Other necessary documents

After County’s review and approval of the above referenced documents, the County will issue the Sewer Extension Permit and the project sponsor can begin construction.

1.5 Project Procedures

The design phase shall include a 30%, 60%, and 90% design deliverables at a minimum prior to issuing signed and sealed documents for construction (Construction Documents). The following items shall be included as part of the design deliverables.

1.5.1 30% Preliminary Design The following items shall be submitted as part of the 30% Preliminary Design deliverable:

• Basis of Design Report following the latest version of the New York State Environmental Facilities Corporation (EFC) Engineering Report Outline. Refer to Appendix B for the most current version of the outline.

• 30% design drawings including the main features of the proposed improvements.

• Preliminary opinion of probable construction cost.

• Project’s complete State Environmental Quality Review.

• Code review and requirements of authorities having jurisdiction (AHJ). Design professional shall provide a draft code path for project.

• Finalize geotechnical investigation. Refer to Appendix C – Subsurface Exploration and Geotechnical Report Requirements.

• Finalize site surveying work.

• Develop site layouts. Refer to Appendix D – Design Submittal Requirements and Checklists

• Table of Contents for Project Specifications.

A Basis of Design Report shall be submitted to the County for approval. The report shall follow the latest New York State EFC Engineering Report Outline. The 30% preliminary design deliverable shall include, at a minimum, a conceptual site layout, force main alignment, design calculations, preliminary pump station control narrative, equipment sizing, phasing, identification of all required easements, building code review requirements, licenses, rights-of-way (ROWs), etc. Additionally, the Basis of Design Report shall provide an anticipated drawing list, broken out by discipline, and a table of contents for project specifications that will be developed for the project. An example tentative drawing list is included in Appendix E. The design professional shall clearly identify all assumptions.

Once completed, the Basis of Design Report shall be signed and sealed by a registered professional engineer in the State of New York and an electronic copy in PDF format along with four hard (4) copies submitted to the County for review and approval. The design professional shall obtain, a DDP NTP from the County, prior to progressing to the 60% design stage.

1.5.2 60% Design The 60% design deliverable shall include at a minimum the following:

• Produce a set of well-coordinated drawings that clearly communicate the design intent/approach for all disciplines.

• Design suitable for detailed review to identify conflicts and refine the opinion of probable construction cost.

• Draft version of the technical specification section of the Project Specifications.

• Updated opinion of probable construction cost.

The plans shall represent approximately a 60% completion level of detail in all disciplines. At a minimum, these plans shall include the following:

• Site plans and landscaping plans

• Civil and electrical site plans

• Civil, structural, mechanical, and electrical details

• Architectural plans, sections, and details (as applicable)

• Grading and drainage plan

• Force main plan, alignment, and profile

• Completed wet well plan and sections

• Single line diagrams

• Control schematics and telemetry

• Completed Process and Instrumentation Diagram (P&ID) as applicable

• Approved code path from the AHJ

The specifications shall follow the 50 Division Master Format developed by the Construction Specifications Institute (CSI) and shall reflect the County’s Equipment Manufacturer List and Material List included as Appendix F. The 60% design deliverable shall be marked as to its stage of development and an electronic copy in PDF format along with four hard (4) copies of drawings and specifications submitted to the County for review.

1.5.3 90% Design Once the 60% preliminary plans, specifications, and opinion of probable construction cost are approved by the County, the 90% design plans and specifications can be prepared by the design professional. The 90% design deliverable shall include at a minimum the following:

• Produce complete drawings and specifications that have passed internal Quality Control (QC) and coordination.

• Design suitable for final review by the County, permit applicable and complete opinion of probable construction cost.

The plans shall be complete including all required site, civil, process/mechanical, electrical, instrumentation and control, architectural, and structural plans, sections, and details. Any proposed deviations to material items within the standard specifications shall be specifically noted and presented to the County for approval at this stage. All Notes to County comments shall be addressed and replaced by appropriate responses.

Key criteria from the Basis of Design Report shall be included on the General Notes sheet of the 90% design drawings. These criteria include, but are not limited to, wet well dimensions and volume, pump capacity and horsepower, force main length and diameter, generator size, etc. This information shall be provided for all phases shown on the drawings. The content of this General Notes sheet, as well as the entire drawing set, will then be discussed in detail with the County and is subject to its review and approval.

The 90% design deliverable shall be marked as to its stage of development and an electronic copy in PDF format along with four hard (4) copies of drawings and specifications submitted to the County for review.

1.5.4 Construction Documents

Final construction documents may be completed and submitted for approval once all previous review comments have been resolved. These plans and specifications shall be signed and sealed by a registered professional engineer in the State of New York and an electronic copy in PDF format along with four hard (4) copies submitted to the County. After County’s review and approval of the final Contract Documents, property acquisition documents, and copies of all permitting agencies approvals, the County will issue the Construction Phase Authorization (CPA) NTP. Upon receipt of the CPA, the project sponsor may bid the pump station using the approved Contract Documents. The design professional is responsible for notifying the County of any proposed changes prior to implementation.

AHJ will issue the building permit for all projects.

1.6 Agencies, Codes and Permits

The design of pump stations in Ontario County shall comply with relevant industry codes and standards, refer to Appendix A for minimum codes and standards to be reviewed during the design of a pump station. The current version of these documents effective at the time of issuance of the PDP shall be used as a reference by the design professional. The permitting agencies reviewing typical projects will include, but not be limited to, municipality with land use control jurisdiction, County DPW, city of Canandaigua DPW, New York State (NYS) Department of Environmental Conservation, NYS Department of Health, and Ontario County Codes.

1.6.1 Permits

The design professional shall attend meetings with the appropriate agencies, along with the County, to initiate informal discussions and determine special permitting requirements that need to be incorporated into the design.

The design professional shall be responsible for completing any and all permit application and notification packages and for submitting them to various agencies for processing. The County shall be copied on all submission to various permitting agencies. The efforts of the design professional will include providing all technical assistance and background studies necessary to meet the requirements of the permitting agencies.

1.6.2 Property Acquisitions and Easements

All property acquisitions and easements must be completed and recorded with Ontario County Clerk before construction can proceed. It is the sole responsibility of the design professional to prepare site surveys, site maps, and legal descriptions and maps of the property acquisitions for filing at the County Clerk’s office.

The acquisition of property rights for pump stations and all associated piping constructed by project sponsors, including ROW and permanent easements, shall be obtained by the project sponsor at their sole cost and expense.

It shall be the project sponsor's responsibility to prepare the required documents in a manner that is acceptable to the County. Deeds and conveyance documents shall be finalized and submitted to the County prior to the start of construction. County Clerk filing information for all acquired property rights shall be provided on the as-built drawings.

1.6.3 State Environmental Quality Review Act

The State Environmental Quality Review Act (SEQR) is a New York State law that requires all state and local government agencies to consider environmental impacts equally with social and economic factors when making decisions on projects or activities. In most cases, the municipality with land use control jurisdiction will complete the SEQR process for the development and proposed pump station. In the instance where a governmental agency or a private entity (project sponsor) wishes to construct a pump station for dedication to the County, refer to https://dec.ny.gov/regulatory/permits-licenses/seqr.

The project sponsor shall coordinate the completion of the SEQR process with the County, as part of the 30% design phase.

1.6.4 State Historic Preservation Office Review

The New York State Historic Preservation Office (SHPO) is responsible for identifying, protecting, and preserving historic and cultural resources across the state. The SHPO review process applies to all projects that involve federal or state funding, licensing, permits, or approvals; or that have the potential to impact historical properties, cultural resources, or archeological sites. Historic properties are defined as those listed on or eligible for listing on the State or National Register of Historic Places (NRHP). For projects involving New York State funding, permits, or approvals, SEQR mandates that agencies assess potential impacts on historic and cultural resources. The State Historic Preservation Act requires consultation with SHPO to identify and evaluate impacts on properties listed or eligible for listing on the State Register of Historic Places. When applicable, the design professional shall submit project information to SHPO through the Cultural Resource Information System (CRIS):

https://cris.parks.ny.gov/Login.aspx?ReturnUrl=%2f.

The design professional shall comply with the review and recommendations provided by SHPO and incorporate said recommendations into the design documents.

1.6.5 Utility Coordination

Utility coordination for proposed pump stations and force mains shall be the sole responsibility of the design professional. The design professional shall establish all necessary utility contacts and shall provide a list of the contacts in the Basis of Design Report.

The design professional shall also be responsible for coordinating the design with impacted utilities, performing review of conflicts with utilities, and establishing and/or confirming the availability of utilities and service requirements. Any conflicts between the utility record drawings and field verification shall be brought to the attention of the utility and the County.

The project sponsor shall establish all necessary utility accounts and shall provide a list of the accounts, prior to the start of construction. Prior to final acceptance of the pump station by the County, the project sponsor shall provide formal written documentation that all subject utility accounts have been transferred to the County.

https://dec.ny.gov/regulatory/permits-licenses/seqr https://cris.parks.ny.gov/Login.aspx?ReturnUrl=%2f

2 Pump Design and Operating Criteria This section outlines the design and operating criteria to be utilized by the design professional for selection of the type, size, and quantity of pumps required for a pump station.

2.1 Wastewater Characteristics

Due to the inherent nature of raw wastewater, all pumps shall be non-clog type suitable for continuous operation for conveying raw, unscreened wastewater. Pumps handling raw wastewater shall be capable of passing solid spheres of at least 3-inches in diameter.

2.2 Allowable Pump Station and Pumping Equipment

Types

The County has begun to standardize around a limited number of pump station configurations to minimize the operations and maintenance costs and provide consistency concerning spare parts and materials. Refer to Appendix G – Pump Station Configuration Decision Matrix. This standardization has resulted in the following three types of pump stations configurations allowable by the County:

1. Submersible Duplex Stations: These stations shall consist of a duplex pumping system using submersible pumps installed within a precast concrete wet well. A separate below-grade pre-cast concrete valve vault shall be installed for this configuration. Triplex submersible pump stations of this configuration are not acceptable.

Electrical pedestals shall be installed at these stations to house the pump drives, automatic generator transfer switch, and control equipment within a weatherproof enclosure mounted to the pedestal. A weather break structure shall be installed around the electrical enclosure and pedestal to protect the enclosure and maintenance staff from the elements. In general, this pump stations configurations shall be utilized for applications requiring design flow rates of 500-gpm or less where the pumps are smaller, and a duplex configuration can fit in readily available precast concrete structure sizes. A method of detecting shaft seal failure shall be included in the design of submersible pump stations. Pumps shall be able to be removed without the need for personnel to enter the wet well, or the need for any piping disconnection.

2. Duplex Wet Well/Dry Well Stations: These stations shall consist of a separated wet well and dry well configuration and separate valve and flow meter vault. Dry wells shall be completely separated from the wet well and any common walls shall be gas and liquid tight such that the dry well is unclassified, and a non-permit required confined space. In general, this configuration shall be utilized for design flow rates between 500 and 1,000-gpm where larger motors require more significant cranes than a light-truck mounted hoist to remove them for service and/or inspection. Additionally, installing pumps within a dry well shall allow for routine pump maintenance to be performed in-place. Electrical pedestals and weather break structure shall be installed at these stations similar to the Submersible Duplex Station configuration.

3. Triplex Wet Well/Dry Well Stations with Superstructure: Triplex pump stations shall generally be utilized when design flow rates exceed 1,000-gpm, where higher peaking factors require a lead-lag configuration to meet average and peak flow requirements while maintaining redundancy. Superstructures shall generally be required for pump stations with motors larger than 50-HP when the size of required electrical equipment exceeds the dimensions of readily available weatherproof enclosures. Superstructures shall be designed and incorporated into the station’s wet well/dry well configuration. Dry wells and their superstructures shall be completely separated from the wet well and any common walls shall be liquid and gas tight.

No other pump station configurations shall be permitted unless approved in writing by the County prior to design.

Duplex and triplex pump stations shall pump in parallel, and pumping is series shall not be permitted. Pumps powered by electric motors shall be the only type allowable. Pumps with diesel, natural gas, petroleum, hydraulic drives, or pumps requiring seal water shall not be permitted. Provisions shall be made for removal of pumps, motors, and all other mechanical and electrical equipment. Removal of pumps and motors shall not impede the operation of the remaining pumps.

A sump pump shall be provided in all dry wells to remove any leakage or draining. The sump pump discharge shall be installed above the high water well within the wet well. Floors and walkway surfaces shall be sufficiently sloped to a common drainage point.

The County has identified specific manufacturers which shall be used by the design professional and incorporated into the design documents. The list of pre-approved equipment manufacturers is provided in Appendix F – Ontario County Equipment Manufacturer List. Deviations from these pre-approved equipment manufacturers shall not be permitted unless authorized by the County in writing.

2.3 Design Flow Criteria

The design professional shall size pumps based on the service area for the quantity of flow at startup as well as anticipated growth within the service area during the anticipated useful service life of the pumps (assumed to be 20-year minimum). The service conditions shall consider both the peak flow and average daily flow. The design professional shall generally utilize the following approach to establish the range of design flow conditions:

2.3.1 Service Area Definition

The design professional shall establish the design flow for each pump station based on the full or projected development and wastewater composition of the service area, including the full development flow from the entire contributing service area at peak flow. At a minimum, the design professional shall determine the following as part of the pump station design, to be included in the Basis of Design report as part of the 30% design deliverable:

• Extents of the service area boundary at initial pump station startup and full development buildout

• Current and proposed land use with the service area

The design professional shall use an area-wide approach including areas within the gravity sewer drainage area that could be served by the pump station in the future. If applicable, the design professional shall document how the pump station will comply with the recommendations of the approved master plan for the service area. If an approved master plan exists for the service area, it shall be incorporated into the analysis of the design flow rates.

2.3.2 Design Flow Development

Once the design professional has established and documented the service area within the Basis of Design report, the full range of design flows for the pump station shall be calculated to determine the appropriate pump station configuration, size, and number of pumps. The design professional shall provide calculations within the Basis of Design report used to determine the average flow rate and peak hourly flow rate at both initial startup and full-service area buildout conditions.

Additionally, the design professional shall calculate the remaining pump station capacity following completion of a proposed development. These calculations shall be used to detail when upgrades would be required (if applicable) for the full-service area buildout conditions

Average Daily Wastewater Flow Rate Average daily flows for primarily residential service areas shall be calculated based on metered water consumption data if available, or the estimated population of the proposed service area. Once the service area and corresponding land uses are established, the zoning determined, and any large facilities identified, the design professional shall complete an estimation of the number of residences, and the total area of commercially/industrially zoned land use can be used to determine the total average daily flow expected to be generated by the service area. This flow rate shall be presented in gallons per minute (gpm) within the Basis of Design report and technical specifications. However, if the development will be constructed in phases, the flows for each phase shall be determined. If applicable, the pump station shall be designed to allow for future expansion of the service area.

The sizing of the pumps shall generally be based on an average daily flow of 100-gallons per capita per day, plus additional wastewater flow from industrial, institutional, and commercial facilitates in accordance with Ten States Standards.

Peak Hourly Wastewater Flow Rate The peak hourly flows shall be calculated using average daily flow rates for the proposed service area and peaking factors in accordance with Ten States Standards and TR-16.

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 =

(18 + √𝑃𝑃)

(4 + √𝑃𝑃)

Where P is equal to the population of the service area in thousands. It shall be noted that this equation covers normal stormwater inflow and infiltration for new collection systems constructed with modern techniques. For existing collection systems where conditions of the gravity sewer may be unfavorable, the design professional shall make provision for an additional allowance.

Alternative Design Flows For pump station serving commercial and/or industrial service areas, alternative means to estimate design flow rates may be required. Institutional, commercial and industrial flows shall be determined by a study of the type of establishment. The design professional shall also consider that wastewater composition can vary based on the percentage of design flow generated by non-domestic dischargers.

2.4 Hydraulic Analysis and Pump Selection

A hydraulic analysis shall be performed by the design professional for the proposed pump station. This analysis shall be used to determine the type and size of equipment required for pump operation. For the hydraulic analysis, the pumping system is hereby defined as the pumps, force main, valves, and fittings.

2.4.1 Pumps

Pumps shall be selected to provide at least 75% efficiency at the design average flow and be selected to operate within 70 to 120-percent of the Best Efficiency Point (BEP) in terms of percent flow. Pumps shall be sized and selected so that all design operating points are on the manufacturer’s published pump curves and shall always operate within the Allowable Operating Range (AOR). Pumps shall operate in parallel. A minimum of two pumps shall be installed at all pump stations. Simplex pump stations are not acceptable. Duplex pump stations shall be sized such that each pump is capable of handling the peak design flow. Where three (3) or more pumps are provided, the pump station shall be capable of handling peak design flow with one (1) pump out of service.

When applicable, the design professional shall consider strategies for varying flow rates between the time of initial startup of the pump station and full build-out of the service area. At each phase of additional development within the service area, pumps shall be sized for efficient operation at average design flows and provide sufficient capacity to handle peak flows. The peak capacity of the pumps shall be by increased by 5% to account for wear of the pump’s impeller and volute, unless otherwise recommended by the pump manufacturer or approved by the County.

For pumps to be installed with variable frequency drives (VFDs) for variable speed applications, the design professional shall factor the pump operation at reduced speeds into the hydraulic analysis and establish minimum speed limitations and the minimum flow rate at which the pump can continuously pump wastewater. Curves shall be provided for 100, 90, 80, 70, and 60-percent of the full speed. All pump motors shall be non-overloading and not exceed the rated horsepower of the motor at any point along the operating curve of the pump.

2.4.2 Force Main

The force main(s) shall be sized to achieve a velocity between 2 and 8-feet per second (fps) for both the initial startup and full buildout of the service area. The design professional shall use either the Darcy-Weisbach and/or the Hazen-Williams equations to determine the head loss versus length of the force main across the design flow rates. Static, dynamic, and minor losses shall be considered for the hydraulic analysis. The design professional shall take into consideration that force mains will have higher “C” factors when initially installed. The impact of a higher “C” factor shall be incorporated into the hydraulic analysis when determining maximum power requirements and pump cycle times.

The design professional shall provide an analysis for water hammer during design if the total dynamic head (TDH) is great than 50-ft, design velocities are greater than 4-fps, or the force main is greater than 8-inches in diameter and longer than 1,000-ft. The analysis of water hammer shall include calculating critical time, determining maximum increase in pressure, and selection of a method of control. To the extent feasible, the design professional shall eliminate high points within the force main to reduce the risk of water hammer. When not feasible, provisions including but not limited to check valves, air/vacuum relief valves, automatic control valves, and surge relief valves shall be required.

2.4.3 Wet Well

The design professional shall size the wet well to provide efficient operation and sufficient capacity at both initial startup and full buildout of the service area. The required storage volume in the wet well shall consider the method of pump operation: constant or variable speed. Regardless of the selected method, detention time of wastewater within the wet well at average design flow conditions shall not exceed 30-minutes. The wet well shall be sized such that the pumps have 2-cycles per hour at a minimum, but do not exceed 8-pump cycles per hour (per pump). Pumps shall be designed for automatic pump alternation to create even wear and runtime for each pump. The total volume of the wet well shall be limited to the wet well itself and shall not include upstream or downstream gravity sewers, force mains, or manholes.

The ”pump off” level shall be selected based on the manufacturer’s recommendations to maintain sufficient pump submergence. The “pump on” level shall be no higher than 1-ft below the invert elevation of the lowest influent pipe to avoid backups. Alarms shall be provided to alert County personnel when the water level decreases below the “pump off” level or rises above the set high water level within the wet well in conformance with Section 5.6.

2.5 Downstream Capacity

The design professional shall conduct an analysis of the hydraulic impacts of the proposed pump station on existing downstream gravity sewer, force mains, and/or existing pump stations to determine if the existing system has sufficient capacity to handle the proposed increase in flow or if downstream modifications are required. If the design professional determines that downstream improvements are required to accommodate the increased flow, this shall be explicitly stated within the Basis of Design report as part of the 30% design deliverable. A meeting will be held with the County and design professional to determine next steps.

3 Civil and Mechanical Criteria This section defines the specific design requirements for each pump station site and associated superstructure, if applicable, based on the pump equipment selection.

3.1 Property Ownership Requirements

The design professional shall provide the County with sufficient property required for the operation and maintenance of the pump station, including a paved access road. The pump station, including a necessary buffer for access and maintenance and a paved access road, shall be constructed on a separately deeded parcel, and such parcel shall be dedicated to the County upon completion of construction, startup, and commissioning.

3.2 Site Development Requirements

Pump stations shall not create nuisance conditions (noise, odor, light, visual, drainage, traffic, etc.) for adjacent properties, and site improvements shall be provided for all-weather access, security, and maintenance. The purpose of this section of this manual is to define all the site plan, permit, and inspection requirements for the projects This section provides requirements for a wastewater pump station parcel including considerations by the design professional for property line setbacks, traffic considerations, noise, odor, and light mitigation for adjacent properties.

3.2.1 Floodplain

Pump station structures and electrical and mechanical equipment shall be protected from physical damage by the 100-year flood. All entrances and/or un-sealable openings of a station shall be above the 100-year flood elevation.

These flood elevations shall be determined from the best available information from sources such as the Federal Emergency Management Agency (FEMA). Regulation of local, state, and federal agencies regarding flood plain obstruction shall be considered.

3.2.2 Setback and Buffers

Setbacks and buffers for the pump station shall be provided in accordance with zoning code standards and to provide sufficient space for operation and maintenance of the pump station. Future expansions of pump stations setback and buffers shall be reviewed with design professional and the County. Show all setbacks and buffers clearly on drawings.

3.2.3 Access Roads/Driveways

Driveways shall be paved asphalt or concrete and designed so that vehicles are not required to back onto public or private streets or roadways. Driveways shall be designed to allow service truck with equipment (i.e. portable generator or pump) sufficient room to completely pull off street/roadway while opening the site gate to gain entrance.

The driveway shall be sloped to facilitate drainage away from the pump station.

To enhance safety and functionality, bollards shall be incorporated into the site design. Either removable or permanent bollards may be installed at the site depending on the situation and site location. The type of bollards installed shall be determined by the design professional for review by the County.

Removable bollards shall be provided where accessibility is required for operation and maintenance. Removable bollards shall be a minimum diameter of 4-inches and include a galvanized schedule 40 steel casing pipe, end cap, lifting eye, and galvanized steel twist lock socket base. Permanent bollards shall be a minimum 4-inch diameter and include a schedule 40 steel pipe filled with concrete. Concrete foundation for the bollards shall be reinforced, 18-inches in diameter, and extend 6-feet below grade. Provide a plastic removable bollard cover for bollards with a color selected by the County.

3.2.4 Water Service

The design professional shall provide source of potable quality water for the pump station capable of providing a minimum of 25-gpm at 40-psi. The potable water shall be used for area washdown, equipment maintenance activities, restrooms and in some instances an eyewash station and/or emergency shower. Water may also be needed for mechanical seals and other process needs. A reduced backflow preventer or other approved device shall be installed on the water service entering the station. Any potable water supply shall not be directly connected to wastewater equipment, piping systems, fixtures. The design professional shall coordinate with the appropriate water utility and obtain all easements required to install the water supply system for the pump station.

3.2.5 Site Layout

Pump stations and all ancillary equipment must be readily accessible to personnel and service vehicles during all-weather conditions. Pump stations shall be located off rights-of-way. Layout of the structures and equipment shall balance functionality and existing utilities with aesthetics and neighboring properties. Additionally, the layout shall account for sufficient space to allow for successful operation and maintenance of the pump station and associated equipment.

3.2.6 Architecture and Landscape

Design professional shall provide landscaping for the pump station to match similar pump station facilities within the County and compatible with the visual appeal of the surrounding neighborhood and environment. Landscaping trees, bushes, and other accessories shall be reviewed and approved by the County. Grading of the pump station site shall uphold a positive drainage away from site structures without negatively impacting the surrounding properties. All power lines for electrical services inside the property lines shall be buried, and overhead power lines shall only be located outside of the pump station’s property line boundary.

3.2.7 Odor Control

Consider the use of odor control devices when the pump station is near a residence, sensitive, or other populated area. For small stations (<300 gpm), a vent with an activated carbon filter or a small exterior drum scrubber on a concrete pad is anticipated at a minimum. For larger stations, chemical addition or a biofilter shall be considered for odor abatement and proper design steps shall be completed to adequate size the odor control system to satisfactory reduce odor emittance from the pump station.

If chemical addition or a biofilter odor control system is required, the design professional shall estimate the annual operating and maintenance cost of the system. The design professional shall make an effort to select an odor control system that meets the design requirements while minimizing the required operating and maintenance cost burden on the County.

3.2.8 Site Security and Fencing

The following general site provisions shall be provided for all pump stations:

• All entry points into pump station structures, vaults, panels, etc. shall be lockable.

• Pump station shall be provided with adequate outdoor and indoor LED lighting to facilitate normal and emergency operation and maintenance activities during daylight and non-daylight hours.

• Safety placards for all pump station structures and equipment, as required by Federal, State, local agencies shall be provided and be readily visible.

• Provide adequate conduit/raceways to power supply, Supervisory Control and Data Acquisition (SCADA), and camera site locations in the electrical building/room as determined by the County.

Where site security is a concern, pump station sites shall be fenced to secure the site, and the fencing shall be a minimum of 8-feet in height. A 20-foot-wide swing gate assembly shall be provided to be secured with a lock and chain at all access points. Gate shall swing in and have self-locking holds/stops.