Condition of the Large Tank


This photo was taken before the seeping area was patched.

The 127,000 gallon tank is generally in very good shape. It was inspected by the manufacturer, Mount Baker Silo, and a licensed structural engineer who tested the  integrity of the concrete and verified the rebar was installed per spec. There is seepage along many of the joints, which is typical of this type of construction. There is one area about 24' up on the South side where soil was mixed in with the concrete. Over the years this area has had excessive leakage. Several attempts to patch the inside and outside.


 View from inside the tank looking at the layers of patches. (click on the picture for higher resolution)
More pictures of the inside of the tank.

Conclusion and Plan

  1. With routine maintenance we expect several decades of operation from the tank.
  2. Continue to monitor the condition of the tank in general and the known weak areas.
  3. Prepare the small tank for regular operation.
  4. Develop a plan to meet the chlorine contact time (CT) requirements, and have the plan approved by the state dept of health before putting the small tank in operation.
  5. If the seepage increases again:
    1.  Test approved alternate CT plan
    2. Clean and disinfect the small tank
    3. Bring the small tank online
    4. Drain and dry the large tank,
    5. Pressure wash the inside of the large tank
    6. Sand blast the interior areas to be repaired
    7. Roto hammer suspect joints and cracks to enable solid repair
    8. Seal areas of concern
    9. Refill, disinfect and bring back online in an approved manner.
New storage for increased capacity is a different issue, and should be funded primarily by the new members.