ATS, Inc. was contracted to treat for colloidal clay turbidity problems associated with the drilling and development of a community drinking water well. Well depth is 1,100 feet and turbidity levels were expected to measure over 1,000 NTU.
Chitosan Enhanced Sand Filtration was selected as a safe, cost effective method. Developing the well required the air lifting of water at 250 psi and pre-treated with Chitosan. Pumping volumes were 360 gallons per minute for up to ten continuous hours, and actual maximum turbidity levels were measured at over 3000 NT. The pre treat water was pumped into two twenty five foot 6000 gallon tanks connected 90 degrees to one another. This allowed 30 minutes of settling time prior to pumping into the main holding tank. Water pumped from the main tank into the sand filter was discharged at levels below 10 NTU on a flow through basis. Total flow through time was approximately 50 minutes from airlift to discharge. Maximum daily volumes were at 210,000 gallons and the total pumped volume exceeded 2.1 million gallons. Discharge water was tested for residual Chitosan Polymer daily, with each test results showing negative polymer discharge.