Citizen's Committee

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CAPACITY ASSURANCE PROGRAM
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What Is the Capacity Assurance Program, or CAP?

• The Capacity Assurance Program shall evaluate
  the impact of new sewer service connections, or
  increased flows from existing sewer service
  connections, to the sewer system to ensure
  adequate system capacity is available to accept
  such flows.

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Why Implement a CAP?

• To satisfy a requirement of the EPA
  Administrative Order
• To maintain compliance with NCDENR Collection
  System Permit
• To further our commitment to be good
  environmental stewards

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CAP Implementation Schedule

• 3/2/08 Submit Draft of CAP to EPA
• 5/1/08 EPA Review Complete
• 9/1/08 Re-submit CAP to EPA for final approval
• 11/1/08 Final Approval of CAP
• 1/1/09 Implementation of CAP

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What Components of the Wastewater System are
Included in the CAP?

• Collection System all gravity flow pipes from
  street mains to large diameter trunk sewers
• Transmission System all sewage pump stations and
  force mains
• Treatment all wastewater treatment facilities

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What Projects Are Subject to the CAP?

• Private developments with a water tap size 1.5
  larger
• New residential developments
• Satellite flow agreements
• New sewage pump stations
• Annexation areas

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What Projects Are NOT Subject to the CAP?

• New sewer connections w/ a water tap 1 and
  smaller (single family homes)
• Street Mains sewer extensions
• Essential services such as healthcare facilities,
  government facilities, necessary septic tank
  elimination

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Capacity Review Thresholds

• Minor Connections are less than 50,000gpd and/or
  less than 10 of available basin capacity
• Major Connections are more than 50,000gpd or more
  than 10 of the available basin capacity
• Thresholds determine level of evaluation

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CAP Integration with Existing Business Processes

• CAP will interface with New Services Section,
  Donated Projects Group, Sewer Rehabilitation
  Group, and CIP Design Construction Section
• Applicant specific information will be conveyed
  and tracked in an information management system
• Direct interaction with the customer will be
  limited, occurring only when a capacity
  limitation is discovered

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System Evaluation Data Sources

• SSO Database
• Network of approximately 50 permanent flow
  monitors
• Pump station records
• WWTP data
• Wastewater hydraulic model

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Core Concepts for System Evaluation

• System performance updated annually, using
  previous 2 years of data.
• 2-Year wet weather event as the defining level of
  service
• Any portions of the system that dont meet the
  criteria will be capacity limited upstream of
  that point

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Criteria for Collection System

• No SSOs caused by surcharge
• Maximum surcharge level in manholes of 1.5 feet
  below the rim elevation
• Criteria must be met during a 2-YR or less
  frequent wet weather event

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Criteria for Transmission System

• Pump station must be able to transmit peak flows
  during a 2-YR or less frequent wet weather event
• Criteria must be met using firm pump station
  capacity

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Capacity Accounting

• Pump stations, flow monitors, and WWTPs will be
  treated as nodes, each with an available capacity
  that will be updated annually.
• Capacity accounting database will track flows
  from a proposed project against the available
  capacity.
• Capacity credits will be tracked on a node basis
  for system improvements.
• Approved connections will be tracked until
  project is activated and flow is tributary to the
  system.

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Capacity Limited Basin Options

• Discontinue new extensions in the basin (not
  including 1 and smaller water taps such as
  individual single family homes)
• Offset flows from new connections with reductions
  in wet weather flows from II removal
• Allow new connections provided that a capital or
  OM project is underway

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SYSTEM PERFORMANCE
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Permanent Flow Monitoring Network
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Pump Stations
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Surcharge SSOs
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Key Points

• EPA approval of system evaluation criteria
• System performance reviewed annually and capacity
  limited areas will change over time
• EPA approval of options to allow growth to
  continue in capacity limited areas

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Criteria for Treatment

• Permitted flows will be tracked against WWTP
  permitted capacities
• WWTP must not have performance issues during 2-YR
  or less wet weather flows

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CMU Facts Figures for 2007

• 3,850 Miles of Water Distribution Mains
• 242 mgd of Water Treatment Capacity at 3 WTPs
• 3,865 Miles of Sewer Mains
• 118 mgd of Wastewater Treatment Capacity at 5
  WWTPs
• 80 Wastewater Pump Stations
• Approximately 230,000 Service Connections