Wet Weather Overflow at Lift Station 6
Kessler Heights is a 1.2 MGD extended-aeration plant serving 4,100 connections, with 14 lift stations. Rain began at 22:00 and 2.4 inches fell in six hours. At 04:10 the Station 6 high-level alarm (wet well 12 feet, alarm at 10 feet 6 inches) reaches the answering service; the crew is dispatched at 04:20. Station 6 has two 350 gpm pumps. The lead pump is running; the lag pump failed to start on a variable-frequency-drive fault. Instantaneous inflow peaks near 900 gpm. At 04:25 sewage began escaping from the wet well hatch and running about 60 feet to a storm ditch that discharges to Fall Creek, a Class C trout stream, roughly 900 feet downstream. The crew restores pumping at 05:05 by manually starting the lag pump on bypass and estimates that 6,000 gallons were released. The station has no emergency storage and no permanent generator.
1. Rank the crew's immediate actions from arrival to overflow stopped, and explain why each is ordered as it is.
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The controlling objective is to stop the release, because every action that does not reduce flow extends the discharge and enlarges the notification and remediation burden.
- Stop the overflow first. Manually start the lag pump on bypass, then bring a portable pump or vacuum truck if the two station pumps cannot keep up with 900 gpm. This is the action that ends the event, and it comes before paperwork.
- Protect people and the scene while pumping is being restored. Barricade the area, keep responders out of the wet well, and treat the spill area as contaminated. Nobody enters the wet well during an active overflow.
- Contain what has already escaped. Berm, dike, or dam the ditch, or deploy a vacuum truck to intercept flow before it reaches Fall Creek, and prevent further discharge from the hatch area.
- Notify as soon as the release is stopped or clearly being controlled, within the regulatory timelines for the state's sewage reporting requirements. Notification is not deferred until cleanup is complete.
- Document in real time. Start and stop times, estimated volume and how it was estimated, the receiving water, the cause, and photographs. This record is the basis for the report and for the corrective action plan.
The ranking is not administrative preference. Delaying notification to finish cleanup, or delaying pumping to make calls, both make the outcome worse.
2. What notification obligations does this event trigger, and what does the record need to contain?
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A release of raw sewage to a stream triggers overlapping obligations, and the operator should not try to satisfy them from memory in the middle of a storm.
Regulatory notifications. Under New York's sewage pollution reporting framework, the publicly owned treatment works must notify the Department of Environmental Conservation and the local health department promptly after becoming aware of the discharge (the statute uses a short, hours-scale deadline), and must provide public notification on a similarly short timeline, with a longer deadline available in some impaired-water situations. The same event is reportable under the SPDES permit, and the 24-hour oral notification provision for noncompliance that may endanger health or the environment is likely to apply because the discharge reached a trout stream. Confirm the exact current deadlines and contact list in the permit and in the agency's spill reporting guidance rather than relying on a remembered number.
What the record must contain:
- Location of the release and the receiving water, with the discharge point identified.
- Start and stop times, and the estimated volume, with the estimating method stated (pump curve, drawdown, duration times rate).
- Cause, including the VFD fault and the high inflow.
- Actions taken and when.
- Whether the release is ongoing, and whether drinking water supplies are affected.
- The person making the notification and the agency contact reached.
Written follow-up and the discharge monitoring report will both depend on this record, so accuracy beats a round number.
3. What should the post-event review cover, and which fixes deserve funding priority?
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This overflow was not caused by the rain alone; it was caused by the coincidence of high inflow, a single failed drive, and no storage or backup power.
Immediate causes to review:
- Why the lag pump's VFD fault went undetected, and whether the station has a pump-failure alarm that is separate from the high-level alarm. A high-level alarm that only tells you the wet well is full tells you too late.
- Alarm response: 04:10 to 04:20 dispatch is reasonable, but the answering service path and the after-hours call list should be tested.
- Whether the crew had a written overflow response procedure and portable equipment available.
Systemic causes to review:
- Inflow and infiltration. A 900 gpm peak against 700 gpm of installed pumping capacity at a station serving part of a 1.2 MGD system indicates rainfall-derived inflow. Smoke testing and manhole inspection of the Station 6 tributary area should follow.
- Capacity and redundancy. The station has no emergency storage and no permanent generator. Either wet-weather storage or a portable generator connection is the highest-value capital fix, because it buys response time in exactly this scenario.
Priority. Emergency power and storage come first; they convert a recurring permit and public health event into a manageable alarm. Alarm reliability and response procedures follow, then the I/I rehabilitation program, which is slower and more expensive but is the only fix that reduces the peak itself.