Eco-friendly Purple Pipes Added to Village Sewer/Water Pipe Project
The following text by H. Groschel-Becker is from a March 29, 2007 news article posted on the Village website.
The Miami-Dade County Water and Sewer Department (WASD) and the Village of Key Biscayne will be partners in the first alternative water supply project in Miami-Dade County. "Purple pipes" to provide reclaimed water for irrigation in public areas will be installed in conjunction with new sanitary sewers and replacement mains for potable water. Treated wastewater will be transported in a new water main to Key Biscayne once the proposed reuse plant at the Central District Treatment Plant on Virginia Key is in service. The Links at Crandon Park public golf course at the north end of the island also will be irrigated with reclaimed water.
"The reuse or purple pipes will be funded completely by a grant from the South Florida Water Management District," said [then-]Village Manager Jacqueline Menendez. "That means the estimated $4.8 million expense will not be covered by Key Biscayne residents." A January 10, 2007 letter from John H. Renfrow, [them-]WASD Director, to the South Florida Water Management District (SFWMD) further explains that the Village was selected for the pilot program because its sewer/water pipe project was already designed and in the permitting process with WASD and other County agencies.
The bidding process for the first phase of construction began on March 15, 2007 with construction scheduled to start in late spring 2007. PBS&J, the Village's engineering design firm for the sewer/water pipe project, received approval from Village Council on March 13, 2007, to develop design and construction documents for the purple pipe component. According to Jose Lopez, the Village's Owner Representative for the overall project, and recently retired Chief of the Water and Sewer Division at Miami-Dade County Department of Environmental Resources Management (DERM), PBS&J's schedule includes permitting approval by DERM by June 1, 2007. Therefore, the reuse element should not delay the start of the overall project.
The project represents a commitment by the County and the Village to the efficient use of South Florida's water resources as well as financial resources. Valuable groundwater from the Biscayne Aquifer will be used as potable water and not wasted on non-potable uses. All consumers in the County may ultimately save money, said [then-]Village Public Works Director Armando Nuñez, who added, "Village-wide savings in irrigation costs could be as much as $50,000 per year once the system is fully operational".
What is Reclaimed Water and Why Is It Transported in Purple Pipes?
Reclaimed water is treated domestic wastewater that can be used for irrigation and other non-potable applications. It is transported in light purple pipes to distinguish it from pipes carrying potable water (Figure 1, right. Caption: Potable plastic water pipes are usually white. Piping for reclaimed water is always purple to distinguish it as non-potable water (PPFA, 2007)).
Wastewater from toilets, sinks, showers, baths, dishwashers and clothes washers from residences and commercial properties on sewer in the Village of Key Biscayne travels through sanitary sewer pipes to the Virginia Key sewage treatment plant. After at least four phases of treatment, the water is discharged into the Atlantic Ocean via a 3.5-mile-long submerged pipe. Once the proposed Central District reuse facility is built, the WASD/Village project will reuse this water to irrigate public land.
The use of reclaimed water for non-potable purposes will help conserve increasingly precious groundwater that is pumped from the Biscayne Aquifer underneath the Southeast Florida mainland. According to the WASD , which provides service to "about 2 million customers", "[a]pproximately 330 million gallons of water are drawn everyday from the Biscayne Aquifer for consumer use" (WASD, 2005). Each gallon of reclaimed water used saves a gallon of drinking water.
Where Will the Village's Purple Pipes Be Installed?
The first phase of purple pipe installation will be concurrent with Phase 1 of the sewer/water pipe project (Figure 2, right. Caption: Map of the 3-zone sanitary sewer and water pipe replacement project planned for the Village of Key Biscayne.). Ultimately, 40,000 linear feet of reuse pipe will be placed to serve public swales, medians and traffic circles west of Crandon Boulevard within sewer project Zones 1 and 2/3 and the Village Green. Village Public Works Director Nuñez reports that WASD will lay the purple pipe near the new potable water lines in the same excavation area. Reclaimed water will enter the Village through a main pipe traveling along the pathway to Calusa Park between St. Agnes and the Harbor Plaza Shopping Center.
Significance of the WASD/Village Project
A fresh water supply crisis is looming in South Florida and other parts of the state. Groundwater resources are insufficiently replenished during years of dry season drought and of below normal precipitation in the wet season. The needs of a growing population and the loss of open land for groundwater recharge to building development place further pressures on the fragile underground aquifer system.
According to the Environmental Protection Agency (EPA), two of every three gallons of wastewater generated by Miami-Dade County consumers are piped into the ocean after treatment (EPA, 2002). The remaining gallon is pumped into deep-seated underground rock formations below the mainland. In contrast, water managers in Pinellas County, on the Florida Gulf Coast, reclaim all wastewater during the dry season. For every three gallons generated by consumers, three gallons are used after treatment to water golf courses, parks and lawns. Deep well disposal is used as a backup method of during the wet season.
The 2005 State of Florida Legislature enacted Senate Bills 360 and 444 in response to the potable water crisis. These bills are unique in that they represent the first "direct statutory link between the state's five water management districts' regional water supply plans and local government comprehensive plans throughout the state" (SFWMD, 2005). Local governments are eligible for state or district funding to implement alternative water supply projects within each district's regional plan. They also must "prepare and adopt a minimum 10-year water supply facility work plan into their comprehensive plans within 18 months following approval of an update to ... [t]he SFWMD regional water supply plan ... currently scheduled to be approved during fiscal year 2006."
Miami-Dade County officials have until May 2007 to present their plan for alternative sources of water to the SFWMD. If the plan is not delivered on time, a building moratorium could be enacted since SFWMD would freeze the county's daily water pumping capacity at 413 million gallons a day (Kalis, 2006). However, SFWMD officials recently said that a building stoppage is not likely to be enforced as long as the County shows it is making progress and is committed to integrating planning with state-mandated water-use goals (Dolan, 2007). Mr. Jose Keichi Fuentes, director of the agency's Miami-Dade Regional Service Center, added, "The county needs to identify how they want to come up with 100 million more gallons of water that will be needed every day to support growth over the next 20 years."
The Key Biscayne municipal wastewater reclamation project will likely be the first of many similar projects throughout the County. Reuse can be a significant component of the County's longer-term plan, according to WASD Director Renfrow; reusing 25% of the County's wastewater would take 10 years to implement at an estimated cost of $600 million to $1 billion (Kalis, 2006). Infrastructure associated with two reverse osmosis plants and ocean water desalinization, other alternative water sources under consideration, would add another $3 billion to $4 billion to the total cost. The SFWMD and State of Florida Department of Environmental Protection will provide some funding, but increases in County water and sewer fees will be needed.
Examples of Other Florida Communities Using Purple Pipes
Reclaimed water is used in the Jacksonville area and northeast Florida to cut back on usage of potable water, reduce pollution, and improve the health of the St. Johns River (Figure 3, right. Caption: Installation of pipe for reclaimed water in August 2006; Nocatee Parkway near Jacksonville (Palka, 2006)). Irrigation with treated wastewater will reduce the flow of nutrients into the river by 73% (Palka, 2006). The purple pipe program will be expanded in the next ten years to serve residential, commercial and recreational areas. Authorities predict that about 40 percent of the St. John's Water Management District's treated water, up from 10 percent now, will be reused.
The City of Pompano Beach, a pioneer in reclamation efforts in Broward County, began planning how to use alternate sources of water in 1979 (City of Pompano Beach, 2007). Paramount concerns of the City were how to (1) provide a supply of fresh drinking water for residents, (2) fight saltwater intrusion into the subsurface aquifer that stores the drinking water, (3) protect the environment, and (4) irrigate property during periods of drought.
Purple pipes, sprinkler heads and water meter boxes are now commonplace in Pompano Beach and distribute treated water from the City's reclamation facilities (Figure 4, right. Caption: City of Pompano Beach wastewater reclamation facility showing purple pumps, pipes and other reuse equipment (City of Pompano Beach, 2007)). An added benefit of the purple pipe program is cost savings. The cost for reclaimed water is 0.48 cents per 1,000 gallons as compared to a minimum cost of $1.61 to $2.72 per 1,000 gallons of drinking water.
City of Pompano Beach Utilities Department, 2007.
Dolan, Dan, 2007. Water officials offer reprieve if county shows progress. Article posted week of January 4, 2007.
EPA, 2002. Executive Summary: Relative Risk Assessment of Management Options for Treated Wastewater in South Florida (PDF).
U.S. Environmental Protection Agency Region 4 website.
Kalis, Eric, 2006. New plants could ward off water shortage, county officials say. Article posted week of October 6, 2006.
MacPherson, Bob, 2005. Nurturing a 'precious commodity'. Tampa Bay Newspapers. Article published on Friday, Sept. 2, 2005.
Palka, Mary Kelli, 2006. Reclamation project will benefit river, Florida Times-Union Online. Article published August 28, 2006.
PPFA, 2007. Sustainability: Plastic Piping Systems and Conservation. Plastic Pipe and Fitting Association.
SFWMD, 2005. Linking Land and Water Planning - 10-Year Water Supply Facility Work Plans (SPLASH10YEARWORKPLAN05.PDF). South Florida Water Management District, October 2005.