2007 City of Gilbert Water Report

  At our Gilbert Water Plant, we add hydrated lime to soften our drinking water. The process we used is called the precipitation softening method which is the removal of hardness constituent's by chemical means. The water that comes out of our wells contain various amounts of dissolved minerals. These minerals are iron, which is soluble in well water, clouds up on exposure to air and deposits yellowish or reddish-brown sediment that stains most everything it contacts. As little as a fraction of a part per million can cause trouble. The other mineral manganese, although much rarer than iron, is also troublesome even in smaller concentrations. Blackish sediment may indicate this problem. These minerals are usually compounds of calcium and magnesium, which are the principle constituents of water "hardness". The hydrated lime added to the water precipitates the calcium carbonate and magnesium hardness into manganese hydroxide. To explain the process of softening further would take many more pages, but I just wanted to give you a general understanding here. I would also like to point out that iron and manganese in your water does not cause any adverse health affects even though they may be making the water look, taste, or smell bad.
  There are four other chemicals that add to the water. We have a coagulant called Manifloc 990-N, which is an activated silica. It helps precipitate the colloided particles resulting from the softening reaction.
  The addition of lime makes the pH of the water go up. We add small amounts of sulfuric acid to stabilize the pH to a more neutral point. The sulfuric acid helps also to keep the sand filters from forming large mass deposits called cluster balls.
  We add fluoride, as you know to protect our children's teeth; it has no effect on our teeth anymore as adults. Fluoride addition is required by law.
  Every six to eight years we have our wells jetted out and chlorinated to keep the well screens clean of debris.
  In the fall of 200 and early 2001 we had two new wells drilled in the vicinity of well three. They are both around 80 feet in depth.
  In 2002 we had the electrical lines installed to the water plant starting in 2003 we placed two 15 hp submersible pumps in the new wells. During this year 2003 we plan to connect the electrical system to the computer and chemical feed system. With this down, the two new wells can be placed on line. A well protection plan will be developed on both wells and will also include well three.
  Wells one and two will eventually have to be abandoned. Even though wells one and two have given a good quality of water throughout the years, their capacity has gone down considerably during the past ten years. With the new laws and statues passed by the state, it would be to costly for the City to repair these wells to their normal capacity.
  In the year 2003 we changed the filter media on two filters and will finish changing the media on filter three this year. In October of 2003 we started five and three will be our primary wells and wells one and two will be our secondary wells. Staring, also in October was the City's Well Protection Project Plan. Our first meeting was on February 18, 2004 with the Water Commission, Council, and State Representative present.
  The City Well Protection Plant has been extended to the year 2011. Shortage of State personnel and more data is needed for completion.
In 2006 the City replaced high service pump and motor on pump number two. Input from Minnesota Power and City Engineer recommended the motor be replaced to 480 volts and all other control's that adapted to our system. In the future the City will save money by replacing high service pump one to 480 volts.
  If you have any questions, please call Richard Homola, Water Superintendent at 218-748-2228. 

** This report is being sent directly to each customer. Anyone requesting a copy of this report may pick one up at City Hall located at 16 South Broadway, Gilbert, MN 55741.