I came across this post from 2005 on an old website that has been inactive for years.  While there is no direct attribution, I believe the author was a gentleman who was politically active in town for years and had a significant background in related technical fields.  His point is that while we take the existence and future utility of our wastewater effluent storage pond for granted, it is a potential hazard when it is near full.

This is particularly relevant to our present situation where the RIB system is being operated at such a low capacity that the storage pond is likely to once again be near capacity sometime next spring.  It’s a shame because the NHDES has said that they are willing to work with Wolfeboro to remediate the RIB site, and Wright Pierce produced a plan that NHDES recommended be implemented.  Even if the site were stabilized and made compliant at the currently permitted 340,000 gallons per day, it would be possible to maintain the pond at minimal levels throughout the year.

Thursday, March 16, 2006

Wolfeboro NH ~ Wastewater Storage Dam ~ Failure Risk

March & April is the critical time of the year when the Wolfeboro Wastewater Treatment Facility Reservoir approaches its capacity of 95 million gallons. This Reservoir is a Class B Dam of “significant hazard potential” (according to the Army Corp of Engineers). The hazard or risk is signifacant due to the many thermodynamic and hydraulic cycles this Dam has experienced throughout its history and due to the fact that this Dam could be subjected to severe seismic activity.

Because this is a Class B Dam, an Emergency Action Plan is required in the event of a catastrophic failure. This Plan was commissioned by the previous Public Works Director and Town Manager in 1998. However, the Plan is deficient in that it does not represent a worst case scenario resulting from failure due to seismic activity concurrent with a full Reservoir. In that situation, the total volume of cascading water and slurry mixture descending upon the Town could be more than 3 times the volume delineated in the EAP because seismic activity can cause liquification of soils.

Furthermore, the recent departures of Town Manager Skowron and Public Works Director Bilafer have created key vacancies in the EAP Notification Call List. Those positions are now being filled by “interim” personnel.

This raises several very pertinent questions:
1. Who is the Emergency Management Director if this Dam were to fail?
2. Will the Town or the State be in charge of emergency response?
3. Who will be in charge of the Emergency Operations Center?
4. Who will be the On-Scene Commander?
5. Has the “interim” Town Manager familiarized himself with the Emergency Action Plan?
6. Has the “interim” Public Works Director familiarized himself with the EAP?
7. Has the Notification Call List been updated as required by NHDES Rules?
8. Has an emergency notification drill been held as required by NHDES Rules?
9. Has the EAP been tested to determine how effected people will be evacuated?
10. Is there a designated shelter for evacuated people?
11. Have alternate response and travel routes been designated in the event of road damage?

These are just a few of the questions that need to be addressed and answered. The people who live and/or work below this dam (“In Harms Way”) may have some other questions of their own.

On 15 March 2006, there was an earthen dam failure in Hawaii and at least 1 person was killed and many others remain unaccounted for. There are earthen dam failures in the USA every year. There have been prior failures in New Hampshire and there will probably be more in the future.