Posts Tagged ‘Saylorville Water Treatment Plant’May 4, 2011
In celebration of National Drinking Water Week, on May 3 the Des Moines Water Works Board of Trustees and staff hosted Des Moines and metro area community leaders at an official start-up of the new water treatment facility located on NW 26th Street.
DMWW’s third treatment plant was commissioned in response to the growing water demand in the northern portion of the Des Moines metropolitan area. The treatment process at the new facility utilizes membrane technology to soften and purify the finished water. This is DMWW’s first membrane treatment plant and the largest such facility in Iowa. The plant will have an initial capacity of 10 million gallons per day (mgd) and can be expanded to 20 mgd.
DMWW values our partnership with the following communities who have purchased capacity and invested in DMWW’s Core Network, which includes the newly commissioned Saylorville Water Treatment Plant.
- Pleasant Hill
- Polk City
- Polk County Water District #1
- Urbandale Water Utility
- Warren Rural Water
- West Des Moines Water Works
- Xenia Rural Water
Des Moines Water Works’ newest treatment plant, Saylorville Water Treatment Plant, is now operational, in manual mode, and pumping finished drinking water into the distribution system. The oxidation of iron and manganese in the pretreatment basin is working well. The oxidized iron and manganese are then removed by the ultrafiltration (UF) process. Part of the UF treated water then goes through the reverse osmosis (RO) process where hardness and other dissolved constituents like nitrate are removed. The remaining UF treated water is then blended with the RO treated water and the mixed waters flow into the finished water clearwell. Fluoride is added and chlorine is added for disinfection. The plant is being operated manually for eight hours each day until all control programming is completed and the plant can be operated from the Control Center at Fleur Drive Treatment Plant.
In response to the growing water demand in the northern portion of the Des Moines metropolitan area, Des Moines Water Works (DMWW) is in the final phase of constructing a new water treatment plant on NW 26th Street, just south of NW 66th Avenue. The plant is nearing completion and should be in service this fall.
The Saylorville water treatment plant will use technology different than the two current water treatment plants. The treatment process will include ultra filtration (UF) membranes followed by split treatment through reverse osmosis (RO) membranes. The first treatment step will be oxidation to precipitate the dissolved iron and manganese in the shallow groundwater. The water will then go through the UF membranes which will filter out all of the particulate (undissolved) material in the water.
After filtration, part of the water will go through the RO membranes and some of the water will bypass the RO membranes. The RO membranes have smaller pores than the UF membranes and are able to filter out dissolved material in the water. The primary removal targets for the RO membranes are hardness (calcium and magnesium ions) and nitrate.
The ratio of water that is sent through versus around the RO membranes will be set to match the hardness of the water treated at the two existing water treatment plants and to ensure the nitrate concentration in the finished water is below the limit for drinking water. DMWW is excited to begin utilizing membranes for water treatment to compare with the operation and maintenance of a membrane plant with the two current lime softening plants.
The treatment capacity will be 10 million gallons per day (MGD) and the plant can be expanded in steps to 20 MGD by adding additional UF and RO membrane units.
Check back with us here on the blog for more updates.
The Raccoon River was above flood stage in Water Works Park seven times in 2010. Even though record high flood levels were not reached, all that water creates a lot of work and makes us wonder what the future will bring.
In 1993 the levee surrounding Water Works’ Fleur Drive Treatment Plant was overtopped by flood waters, leaving the Des Moines without water for more than a week. Since then a number of projects have been completed to help ensure this does not happen again.
Most importantly, the levee surrounding the Fleur Drive Plant has been raised by six feet to a level four feet above the record 1993 water level. A flood gate has also been added which can be closed quickly as compared to the earthen plug that was used to close the levee in the past. These improvements have not seen water as high as 1993 but they were tested during the flooding in 2008 when more than 8 feet of water rose against the 14-foot tall flood gates. The levee and flood gates performed well and treatment plant facilities were protected.
In addition to levee and flood gate improvements the Water Works has added additional sources of supply since 1993. In 2000 the LD McMullen Water Treatment Facility went into service near Maffitt Reservoir with the ability to produce up 25 million gallons of water per day. Four aquifer storage and recovery wells have also been constructed around the metro with a combined capacity of over 10 million gallons per day. Later this year the new Saylorville Water Treatment Plant will go on line with the capacity to supply up to an additional 10 million gallons per day to the metro area. Taken together these facilities provide valuable backup to the primary Fleur Drive Water Treatment Plant.
All of these changes have helped protect the water supply but Water Works Park is still vulnerable to flooding. Just this year the high water has caused tens of thousands of dollars of damage to park roads, plantings, and other park facilities. Each time the water level goes above flood stage the cleanup effort in the park requires hundreds of man hours to complete. In addition high water resulted in the cancellation or relocation of numerous events scheduled on park grounds including concerts, cultural festivals, and family gatherings.