- City Government
- Departments H-Z
- Water Department
- Water Quality
- Sodium hypochlorite (Bleach)
- Sodium Bicarbonate
- Sodium Carbonate
- Sodium Polyphosphate
- Monosodium Phosphate
Sodium Hypochlorite (Bleach)
This is added to Chicopee’s drinking water for disinfection. It is important to note that disinfection is the elimination of pathogenic disease causing organisms only, where sterilization is the complete elimination of all living organisms. Chlorine levels in the treatment plant finish water are approximately 1.0 to 1.4 mg/L free chlorine.
Less chlorine is needed during the colder months of the year to maintain a residual at the further extremities of the system. Our year-round target is 0.2 mg/L free chlorine at the furthest points in the system. Usage ranges from 15 to 25 gallons of sodium hypochlorite per day, depending primarily on water temperature and usage.
Chicopee’s water also receives disinfection with Sodium Hypochlorite (bleach) at the Ware Disinfection Facility in Ware, Massachusetts before it reaches Chicopee. The dose leaving the facility has ranged from 1.2 to 1.6 mg/L over the past few years. This water flows through the Chicopee Valley Aqueduct (CVA) to Chicopee, Wilbraham, and Fire District 1 of South Hadley. When the water reaches Chicopee, the chlorine residual is approximately 0.5 to 0.6 mg/L free chlorine before it is increased to a level that will assure disinfection of the City's distribution system.
Sodium Bicarbonate (Baking Soda) NaHCO3
This is added to Chicopee’s drinking water primarily to increase the water’s alkalinity, therefore reducing its corrosivity. Alkalinity is a measurement of the buffering capacity (resistance in pH change) of water. Sodium Bicarbonate will increase the pH of the water as well, though much more is needed to increase it as compared to Sodium Carbonate. Usage is approx. 800 - 1,500 pounds per day depending on time of year, flow, etc. Sodium Bicarbonate addition is adjusted so that there is an alkalinity after treatment of 25 - 30 mg/L. The water before treatment has an alkalinity of about 5 mg/L.
Sodium Carbonate (Soda Ash) Na2CO3
This is added to Chicopee’s drinking water to increase the water’s pH. It will also increase the water’s alkalinity though if only sodium carbonate was used, our targeted pH would be reached far before our intended alkalinity. The raw water pH is approx. 7.0 and after treatment with Sodium Carbonate and Sodium Bicarbonate the finish water pH is approx. 8.0. This pH adjustment along with an increase in alkalinity reduces the water’s corrosivity. Usage is approximate 10 - 25 pounds per day.
This chemical is primarily used to reduce red water problems caused by iron water mains. It does not remove the iron from the water, but stops it from oxidizing to the visible red state (rust). Therefore, the iron is still there, but in a colorless form. This chemical process is known as sequestering.
As the water goes through the distribution system, some of this polyphosphate also reverts to orthophosphate. Usage is approximately 50 - 80 pounds per day and is adjusted to maintain a finish water phosphate dose (when combined with Monosodium Phosphate) of approximately 2.0 mg/L total phosphate and 1.0 mg/L orthophosphate.
This chemical is primarily used to reduce lead and copper in drinking water. It leaves a protective film (deposition of phosphate compounds) on the inside surface of pipes providing a barrier between the water and the pipe, therefore reducing corrosion. This type of corrosion control is called passivation.Usage is approximately 50 - 80 pounds per day and is adjusted to maintain a finish water phosphate dose (when combined with Sodium Hexametaphosphate) of approx. 2.0 mg/L total phosphate and 1.0 mg/L orthophosphate.
Note: The blending of these 2 phosphates has been found to reduce copper corrosion better than either type can individually.