Project Improvements
The new West Parish Treatment Plant will retain many of the same treatment steps as the existing plant, while introducing new technology and processes. Below are some of the key upgrades that will bring 21st century water treatment to the Springfield region.
New Backwash Facility
In November 2023 a new Backwash Facility was completed. A “backwash” refers to a process to clean dual-media filters (or “rapid sand” filters). The new facility replaced backwash pumps dating from 1974 that had become obsolete and difficult to repair. In addition, the facility contains a new “clearwell,” which holds filtered water used in the backwash process. The old clearwell dated from 1925.
Redundancy was incorporated into the backwash pumps and the new clearwell to allow for regular maintenance. The new Backwash Facility will also allow for continuous water treatment during construction, which will take place on the site of the old clearwell.
Elimination of Slow Sand Filters
Slow sand filters are large underground chambers where water is filtered through sand. They were the predominant treatment process when West Parish Filters was originally built in 1909 until the early 1970s. When West Parish was upgraded with more advanced “rapid sand” filters in 1974, the slow sand filters remained to supplement filtration during periods of high demand.
Slow sand filters built in 1925 will be demolished to make way for the new treatment plant, but components of them will remain – both their sand and the concrete will be utilized incorporated into fill for the new plant. In addition, the manual handwheel gate valve operators and copper shutters from the slow sadn regulator house will be on display in the administration area as a reminder of the site’s history. Four remaining slow sand filter chambers dating from the 1950s will remain on-site but unused.
Dissolved Air Flotation
A new treatment step will be added to the new West Parish Water Treatment Plant called “dissolved air flotation ” (DAF). This step will help resolve issues with disinfection byproducts by removing more dissolved organic material (“organics”) from the water prior to filtration. DAF removes organics by floating them to the top using tiny air bubbles, where the organics can then be skimmed off. This “clarified” water will then flow to the filters.
Rapid Sand Filter Upgrades & Expansion
Rapid sand filters can filter a much larger volume of water in less time than slow sand filters. Rapid sand filters, or “dual media” filters, contain anthracite layered over sand. The filters remove organic particles and pathogens from the water, improving its color, taste, and odor. The new plant will have 10 rapid sand filter chambers, an increase of four from the existing plant. The new Backwash Facility will be utilized for regular “backwashes” (or cleaning) of the rapid sand filters.
New Disinfection Approach
The existing plant uses chlorine gas to disinfect water, a common process utilized throughout the United States and developed world for decades. The new West Parish Water Treatment Plant will use liquid sodium hypochlorite (chlorine), which will achieve the same disinfection in a much safer way.
Solids Handling
The DAF and filtration processes produce accumulated solids that require management and disposal. At the existing plant, backwash water from when the rapid sand filters are cleaned is currently discharged to Cook Brook and directed to lagoons where solids settle and accumulate, and must be periodically cleaned out. In the new West Parish Water Treatment Plant, most solids will be generated through the DAF process. These solids will be “dewatered” using centrifuges, and transported for disposal off-site. The separated water will be recycled to the start of the plant.
New Admin Building and Lab
The existing West Parish Filters Water Treatment Plant was designed not only for 1970s technology, but a 1970s workforce. The administration area of the new West Parish Water Treatment Plant will incorporate accessibility and modern features to support today’s productivity needs. A new flexible space to accommodate educational programs and activities will also welcome visitors to learn about their drinking water. The laboratory will also be upgraded with modern equipment and more space to facilitate the processing and analysis of over 50,000 tests a year.
HVAC Efficiencies
The heating and ventilation system for the new building will conserve energy by using cold-climate heat pumps for heating process areas, heat-recovery variable refrigerant flow systems for administration areas, and free cooling for process areas using process water as a heat sink. This approach will reduce energy consumption by 50% and greenhouse gas emissions by over 70%.
