July 31, 2014 City Commission Meeting

Announcements

No formal announcements, upcoming events, deadlines, or important dates were mentioned during this special call meeting.

Key Discussions & Recommendations

The City Council held a work session to discuss the Wastewater Treatment Capital Improvement Plan (CIP) and Wastewater Collections Master Plan, presented by Corello Engineers and Smith Roberts and Baltiswailer. The discussion focused on critical infrastructure needs and regulatory compliance.

Wastewater Treatment Master Plan (South Plant)

• Aging Infrastructure & Regulatory Compliance: The South Wastewater Treatment Plant is old, but its process is currently working. However, it previously violated wet tests (toxicity levels) due to issues with digester solids releasing ammonia. City staff successfully addressed this, and the plant is currently in compliance.
• Critical Improvements to Avoid Major Costs: Engineers emphasized that the plant is in poor condition and difficult to maintain. To avoid a potential $30-40 million plant replacement or a $47 million pumping option to the North Plant, two immediate critical investments were recommended:
  • Headworks Improvements: A new headworks facility is crucial to protect the plant from wear caused by grit and rags. This project is estimated at $5.4 million for budgetary purposes and keeps future options open.
  • Digester Improvements: Repairing and upgrading the anaerobic digesters (mixing, heating, methane capture systems) is essential for managing biosolids, preventing ammonia release, and ensuring safety. This project is estimated at approximately $6 million.
• Regulatory Urgency: The Oklahoma Department of Environmental Quality (ODEQ) has indicated that failing three consecutive monthly wet tests could lead to permit rescission and imposition of ammonia limits, which would necessitate a costly plant replacement or pumping solution.
• Deferred Projects: Other projects, such as rotating arm replacements and influent pump station rehabilitation, can be deferred and addressed over time.

Wastewater Treatment Master Plan (North Plant)

• Better Condition, but Capacity Issues: The North Wastewater Treatment Plant is in much better condition but experiences excess flow issues during wet weather events.
• Key Upgrades:
  • Excess Flow Pump Station and Holding Basin: A high-priority project to manage and equalize flows during storms, as the current holding basin is too small. This is estimated at approximately $5 million.
  • Septage Receiving Station: Recommended for construction at the North Plant (estimated $250,000) to generate revenue and handle septage more efficiently. The South Plant currently receives septage but lacks the capacity and is more challenging to manage. The new station would be automated and designed for 20-25 years of service.

Wastewater Collection System Master Plan

• Inflow & Infiltration (I&I) Issues: The collection system experiences significant I&I, where rainwater enters the sanitary sewer system, especially on the south side of town. This reduces efficiency, increases operating costs, and can cause back flooding and compliance issues.
• System Evaluation & Recommendations:
  • Manhole Upgrades:
    • 184 manholes located within the 100-year floodplain and within one foot of the flood elevation are recommended to be raised one foot above the base flood elevation.
    • 33 manholes located in roadways (where raising is not feasible) are recommended to be sealed with watertight lids.
    • All raised and sealed manholes require interior rehabilitation (waterproofing).
  • Pipe Capacity Upgrades: Six existing 27-inch pipes, primarily upstream of the South Plant, were identified for potential upgrade to 30 or 36-inch. However, further assessment after I&I reduction is recommended.
  • Data Collection: The current hydraulic model is incomplete due to missing data. Recommendations include:
    • Collecting rim and invert elevations for all approximately 3,500 manholes (538 already surveyed).
    • Conducting Closed Circuit Television (CCTV) inspections of pipes within the floodplain to identify damaged sections.
    • Performing point repairs on identified damaged sections.
    • Implementing GPS as-builts for all future utility projects to maintain an accurate and up-to-date model.
• CIP Priority (Collection System):
  • Year 1: Data collection, manhole addressing (raising, sealing, interior rehab), CCTV, and point repairs. Estimated cost: $1.5 million.
  • Subsequent Years: After I&I is addressed and flows are re-measured, a decision will be made on the necessity of the pipe capacity upgrades (estimated $815,000).

Financial Matters 💰

The total estimated immediate capital improvements for the wastewater system (treatment and collection) are approximately $18.5 million over the next 0-5 years.

• South Wastewater Treatment Plant:
  • Headworks Improvements: $5.4 million
  • Digester Improvements: $6 million
• North Wastewater Treatment Plant:
  • Excess Flow Pump Station & Holding Basin: ~$5 million
  • Septage Receiving Station: $250,000
• Wastewater Collection System:
  • Data Collection, Manhole Upgrades, CCTV, Point Repairs: $1.5 million
  • Pipe Capacity Upgrades (if needed): $815,000

Discussion included potential funding mechanisms such as sales tax, tax increment financing (TIF), State Revolving Fund (SRF) loans, revenue bonds, and utility rate increases. A "cost of service study" was suggested to determine financing strategies. Other cities in Oklahoma have faced similar, often larger, expenditures for wastewater infrastructure.

Public Comments

No public comments were taken during this work session.

Agenda Summary Table