Below are some common questions about Topsfield's water treatment processes and the water treatment plant project. Please call the Water Department if you have any additional questions or would like more information.
1. How is our water currently treated?
Topsfield's water receives the following treatment before entering the distriubtion system:
- Disinfection - Sodium Hypochlorite is added to disinfect the water.
- Fluoridation - Sodium Fluoride is added to prevent tooth decay.
- pH Adjustment - Potassium Hydroxide is added to reduce Lead and Copper corrosion rates.
- Sequestration - An ortho/poly-phosphate blend is added to the water to delay the creation of nuiscnace manganese particles.
These treatment processes are done through 'inline' treatment. The chemicals are added to the water by a positive displacement pump as the water leaves the source water facility. Some reactions take place quickly such as pH adjustment and fluoridation but others such as disinfection take some time to run to completion. Inline treatment does not remove any constituents from the water, we are only able to add things to the water.
2. How will a treatment plant improve water quality?
A treatment plant offers several advantages including:
- It will be able to remove constituents from the water such as manganese, bacteria and viruses.
- Manganese removal will lead to lower chlorine doses because sodium hypochlorite is consumed when it oxidizes manganese so we have to add extra chlorine to account for the loss.
- The plant will include a clearwell for additional water storage and to increase disinfectant contact time. This will allow the chloine reactions to get closer to completion before the water is pumped into the distribution system. Currently, these reactions take place in the distribution system.
3. Will a home filter system remove manganese?
A typical sediment filter removes particles 10 to 30 microns or larger but allows smaller manganese particles and dissolved manganese to pass through the filter. Reverse osmosis, greensand filters and water softeners can remove more manganese from the water.
4. Can we comply with MassDEP's requirements by installing filters in homes?
MassDEP regulations ( 310 CMR 22.23 (4) ) allow systems to install Point-of-Use or Point-of-Entry devices to meet treatment requirements under the following conditions:
- the device shall be owned, controlled, operated and maintained by the public water system
- the device shall be equipped with mechanical warning device to automatically notify customers of operation problems
- the device must be appoved by MassDEP
It is simply much easier for the Town to construct and maintain one large treatment system than 1,800 small ones.