Nutrient Discharge Rules Make Reuse Attractive
Reclaimed water projects shifting into super-hot growth category
- By Debbie Bolles
- Aug 01, 2007
Two cities that have been reusing water for more than five years are expanding their programs to serve additional customers and meet new nutrient discharge restrictions, exemplifying a national trend toward water reclamation.
One such development is a plan by the Hampton Roads Sanitation District of Virginia Beach, Va., to deliver highly treated wastewater to two U.S. Navy bases. The second is the expansion in Cary, N.C., of a piped reclaimed water distribution system to businesses and residences for irrigation.
In both cases, reclaimed water is treated domestic wastewater deemed safe and effective for non-drinking purposes. Though more controversial and less commonly known, reclaimed water is discharged into some drinking water sources in the U.S., such as by the Orange County Water District of California, which has been injecting treated wastewater into groundwater since 1976. Another example comes from the Upper Occoquan Sewage Authority of North Virginia, which discharges reused water into the Occuquan Reservoir.
Nutrient Caps Drive Water Reclamation
A lack of state-level regulations for reclaimed water use has hindered its expansion. The U.S. Environmental Protection Agency provides only voluntary guidelines on the subject. That trend appears to be shifting, however. In Virginia, that state’s agency is currently working on rules related to reclaimed or recycled water, with an estimated adoption date later this year.
“Water supply issues are driving regulations in a lot of states. In this state, what’s really driving it is nutrient caps on discharges,” said Valerie Rourke, water reuse coordinator for the Virginia Department of Environmental Quality (DEQ).
In 2005, the Virginia General Assembly passed legislation setting up a nutrient trading program and requiring operators of wastewater treatment plants by 2011 to reduce the flow of nutrients into Chesapeake Bay. The DEQ started working on regulations pertaining to reclaimed water about two years ago, covering such issues as standards for reclaimed water, appropriate uses, and which users much obtain state permits.
Hampton Roads, which operates under a Virginia Pollutant Discharge Elimination System permit, began selling reclaimed water in 2002 to a Giant Industries refinery in Yorktown, Va. The York River Treatment Plant diverts 500,000 gallons of reclaimed water daily, following treatment, to the nearby refinery. This reclaimed water is used for cooling and other industrial purposes.
“We just saw water reuse as the future, so we started there. That was the first industrial reuse project in Virginia,” said Karen Harr, chief of water reuse for the Hampton Roads Sanitation District.
Success of that initiative led the district to explore other water reuse partnerships. This past spring, the district broke ground for a new water reclamation piping system to deliver highly treated wastewater from the district’s Atlantic Treatment Plant in Virginia Beach. By this fall, the system should be operational, delivering 14 million gallons per day of treated wastewater to the U.S. Navy Dam Neck Base in Virginia Beach. This supply will be used in base heating and cooling. The Navy paid an estimated $500,000 for the project.
A second partnership with the Navy is in negotiation stages and would involve piping reclaimed water to the Norfolk Naval Station, where it will be made into steam for heating and cooling. In that arrangement, Hampton Roads would divert 1 million gallons of reclaimed water daily from its Army Base Treatment Plant in Norfolk.
“We are trying to do what we consider to be the right thing environmentally. If we can defer or delay upgrades to our treatment plants, that saves ratepayers from rate increases,” Harr said .
Cary, N.C. Expands Piped
Water Reclamation System
In Cary, N.C., a reclaimed water distribution system pumps up to 5 million gallons of reclaimed water per day to both homes and businesses for irrigation and cooling. The purple piping system is separate from pipes carrying drinking water to Cary customers. The program also has a bulk water permit that allows approved contractors to pick up the bulk water from either of two water reclamation facilities. Some of the approved uses for the water are: irrigation, dust control, road bed aggregate compaction, and other permitted non-discharge uses.
"The main foundational system was completed in 2001, and it was set up so it could be easily expanded. We since that time we have expanded in very small increments," said Rob Bonne, utilities director for the town of Cary, N.C.
In the northwest part of town, the town plans to build a connection from Cary’s water reclamation system to the Triangle Water Reclamation Facility owned by Durham County. This will provide reclaimed water to customers in part of Research Triangle Park and to the town of Cary’s Thomas Brooks Park, the site of a USA Baseball national training center.
Once the water reclamation line is expanded to that part of town – estimated by 2015 – the connection to Durham County’s system will end. As of March, Cary’s reclaimed water system served more than 500 residential and commercial customers encompassing 17 miles of piping throughout the town.
Residents or businesses interested in using the reclaimed water and that have access to the distribution line must apply to the town to begin using the water, which is sold at a lower rate than that of regular drinking water. The fixed rate is $3.28 per 1,000 gallons of reclaimed water compared with $5.33 per 1,000 gallons for irrigation service from drinking water. Users of the reclaimed water must complete a 15-minute training program.
"One of the advantages of using reclaimed water is we’re recycling wastewater treatment plant effluent, which has some nutrients in it. When those nutrients go on the grass for irrigation, they don’t end up in the river," said Bonne, referring to the Neuse River, where treated wastewater eventually goes.
As communities become more conservation-oriented or take steps to avert water shortages and wastewater discharge impacts, reclamation has become increasingly popular. As in Virginia, financial benefits are a key factor.
"We see a trend in the state of North Carolina in reclaimed water, especially with communities that are constrained by limited water plant production capacity or a limited amount of nutrients they can discharge from their wastewater plants. The ones that are constrained are really accelerating their reclaimed water programs," said Bonne.
Drought-stricken regions, such as California, Texas and Florida, have led the industry with development of water reclamation projects. But as seen with these Virginia and North Carolina projects, expanded use of reclaimed water is becoming a national trend.
This article originally appeared in the 08/01/2007 issue of Environmental Protection.
Debbie Bolles is managing editor of Water & Wastewater News.