A residential community for active adults in Columbus, NJ, finds drought solutions through water reuse.
By Lori Lovely
Homestead at Mansfield, a residential community for active adults in Columbus, NJ, became the site of the Garden State’s first residential application of reclaimed water for beneficial reuse last August when the Applied Water Management Group (AWMG) of American Water installed a reuse system on the property. “It’s the first project of its type in New Jersey,” emphasizes Spencer Pierini, an engineer with American Water, who preformed design work on the system. The project will provide reclaimed water to the lawns and common areas of the community, thereby reducing strain on the state’s water supply.
“Because we get droughts, we worried about maintaining our water supply,” explains Joe Lawrence, president of the Homestead at Mansfield Homeowners Association (HOA). “Normally, we use the ponds for irrigation, but with over 1,000 homes now, when we have a drought, it’s not enough.”
An estimated 140,000 to 160,000 gallons of water pass through toilets, showers, and sinks in the community. Alleviating the ponds (that feed the underground system of sprinklers) by pumping in clean reuse water could ease the burden on potable water supplies when rain and runoff don’t keep the ponds full. As a supplement for stormwater irrigation resources, the system has the power to alleviate pressure on the potable water supply during droughts by supplying up to 250,000 gallons a day. The community will never have to shut down its irrigation system because of water shortages.
Intended to supplement the existing supply of irrigation water, Pierini stresses the fact that this system is intended to supplement rather than replace the current supply of irrigation water. “It’s backup only. It is not intended to be used as the sole source of irrigation water on a continuous basis.”
Timing
Having a supplemental source for irrigation during drought periods might seem like a luxury, but Andrea Brosky, with the Homestead at Mansfield HOA, says it’s been an issue for 10 years. “We’ve had two droughts in recent years. There’s not enough water to irrigate 1,200 homes.”
Pierini says it was a matter of timing, explaining that the HOA approached the AWMG after the purchase of the facility, while it was in the process of upgrading the treatment plant. After experiencing drought, he says, the HOA “decided to proactively search for ways to combat future water shortages to prevent the use of the potable water supply for nonpotable situations and ease the strain on the aquifer. It was a special circumstance.”
Lawrence approached the AWMG about reusing wastewater for community irrigation, commissioning the organization to determine the feasibility of integrating reuse design requirements into the existing wastewater and irrigation infrastructure. A former business administrator for Bordentown, NJ, when it built a sewage plant, he had some familiarity with the process. “I did my homework before I approached them.”
The AWMG, a subsidiary company of American Water, is a water and wastewater utility company that acquired the community’s existing wastewater facility in 1999 after the previous owner was unable to identify and correct ongoing problems. The company continues to provide regulated sewer service to the community. The 20-year-old treatment plant had decayed and was in need of major upgrades, according to Pierini.
Upgrades to the wastewater treatment system were developed in conjunction with the New Jersey Department of Environmental Protection (DEP) to improve water quality. Moving-bed sand filters were installed, the chlorine contact tank was retrofitted, and the lining to the storage/treatment lagoons was replaced. Waste Water Treatment Fund (WWTF) upgrades are still being performed on the plant in order to ensure compliance with all applicable state environmental permit limits, Pierini adds.
Ultimately, the former chief executive officer of the AWMG, Mark Strauss, made the decision in partnership with the Homestead at Mansfield HOA. “It really came down to being able to do a positive thing for the community served by the WWTF,” Pierini elaborates, “as well as being able to demonstrate commitment to company and state goals in terms of responsible environmental and water resource management.” He indicates that the company has “always taken the perspective that we are stewards of our environment” and that it tries to implement reuse whenever there’s a need and economic feasibility.
Making Water Fit to Reuse
Wastewater from the sprawling 295-acre community enters a series of secluded lagoons at the back of the facility, where primary settling, aeration, and biological processes occur. Lagoon liners act as the first major filter. Self-cleaning, continuously moving sand filters are the second. Water is then pumped from the lagoons to one or both sand filters, where it receives an injection of polyaluminum chloride and assorted polymers. The polyaluminum chloride enables coagulation of solids to be filtered out; the charge is changed to allow the particles to bond so they can be removed through filtration. Filtered effluent (minus the solids) undergoes chlorine disinfection and chlorine removal to rid it of leftover ammonia and bacteria. As Pierini points out, the system is not allowed to discharge chlorine-laced water.
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Photo: Buchanan |
| Onsite water treatment systems like this one could become the solution for communities nationwide. |
A diversion chamber constructed by the AWMG then redirects the wastewater to an adjacent stormwater detention pond, Lake Amy. The water level in Lake Amy is constantly monitored to provide a stormwater buffer. Reuse water is transferred to public areas and private residences via a submersible pump. “The water runs from their plant to our lakes,” Lawrence elaborates. “We then use our pump for irrigation. That’s why the water must be pure. We rely on them to monitor the purity of the water.”
Pierini credits the upgrade of the moving-bed sand filters, which was part of the original upgrade plan, as being primarily responsible for achieving reuse water quality. “They had a bad solids problem; they didn’t meet effluence requirements. We brought the solids down to an acceptable level.” The only way to meet the requirements, he says, was to install a series of automated monitoring systems specifically for reuse systems to analyze solids and corresponding nephelometric turbidity units. A free chlorine-monitoring probe was also installed to check the 15-minute chlorine contact time to ensure the proper residual chlorine level is met. If any condition is not satisfied, Pierini explains, the system automatically shuts down until it can be checked, thereby preventing discharge of water that doesn’t meet the prescribed requirements.
Since excess wastewater is discharged into a nearby creek, it’s essential that it’s properly treated. The treated water contains fewer bacteria than the stormwater runoff normally in the pond. To make sure it stays that way, the AWMG regularly tests to ensure compliance with the state DEP requirements.
Prior to implementation of the reuse system, all water-quality testing was performed manually. The treated wastewater was directed to the AWMG’s permitted outfall, which discharges to a tributary of Assiscunk Creek.
Getting the system in place was no easy task. Pierini cites “a multitude of difficulties” during installation but insists that most of them were from an operational perspective. The major operational issue he describes involves Lakes Amy and Anna, the two main ponds serving the irrigation system. “The irrigation network is served by two stations. Lake Anna has outfall that’s nonpermitted; it spills over to other surface water. We can’t operate a pump station while using reuse water. We only operate a pump at Lake Amy. We recommended improving the depth—the amount of water over the intake—to reduce the pressure; otherwise, we’d have to update. We evaluated raising the invert and the level of the pond, but we needed a permit to build a dam. We did studies, but it would be exorbitantly costly. It was going to be $50,000 just to get a dam permit. So, we had to reduce the level of the lakes by digging out the bottom. We have to keep a 6-inch buffer below the outfall.”
The state has to be notified of any operational changes, Pierini says. Since installation, the only change to the system involves installation of a clarifier to the moving sand bed filters. “Algal plumes occur from time to time,” Pierini explains, “so the clarifier is to reduce the solids going to the filters, which will allow the duration of continuous operation to be increased.” These upgrades are required to meet the existing environmental discharge permit but also have the added benefit of further improving the reuse-system water quality and reliability. There are no restrictions on its use, but it is nonpotable. With no plans for expansion of the system, Pierini doesn’t anticipate any further changes.
The Cost of High-Quality Water
The reuse and diversion monitoring system installed at Homestead at Mansfield cost approximately $100,000 to construct, although Lawrence claims the HOA hasn’t spent “any money yet; American Water has been paying.” Actually, a grant from the New Jersey 1981 Water Supply State Bond Fund assisted with the cost of the unit. The bond fund consists of money left over from previous projects, Pierini explains, and is allocated for water projects involving water conservation and water sustainability. He estimates the fund has about $35 million available.
Awarded by the New Jersey DEP, it covered the cost to install the water diversion system that pumps the reuse-quality effluent to Lake Amy and to install the water-quality monitoring system to ensure that the reuse water meets DEP standards for the reuse of reclaimed water. “The reuse diversion system was mostly covered by the grant,” Pierini says. “The cost of the system won’t be spread to the consumer.”
The main components are “in line with most of our other projects,” Pierini claims, noting that in most cases, the company uses membrane bioreactor systems because they are simpler, are more consistent, and have a smaller footprint. Additionally, they’re becoming more affordable. “We try to use them as much as possible. They’re better, and they’re getting cheaper.”
In addition to a small investment, he says, the costs to maintain the system have been minimal. The system requires quarterly testing but “not a lot of labor hours. Turbidity always has to be monitored; we report to the state.”
Because there is no water savings during normal operation of the irrigation system, there’s no payoff for incorporating the system. The real value, according to Pierini, is generated by alleviating some of the strain on potable water supplies and the aquifer that serves the area during drought conditions.
Brosky notes that Homestead at Mansfield hasn’t needed to use it yet, but it anticipates no issues. Pierini adds that the system has “only been operational for a few summer months” because “fortunately, the community received enough rain to sustain its irrigation needs without the reuse system.” With an average annual rainfall of 45 inches, there’s no telling when it might be needed. “It’s dormant right now but is ready to use with a little prep time.”
The system is intended as a supplementary source of water, but Pierini divulges that “we’re not going to prevent them from using it whenever they want.” As a matter of fact, Lawrence authoritatively declares, “If we want to use water from the sewer plant, we’ll simply open the valve anytime we want.” He indicates the community plans to use it on a regular basis.
Although it’s the community’s right to use the water as it sees fit, Pierini cautions against overuse, out of concern for other environmental issues. Because the community discharges to Assiscunk Creek, it could potentially affect the ecology. “Let’s put it this way: If several plants that normally discharge into the creek suddenly stopped, water levels would drop. There’s a finite amount of water. That’s why we maintain a 6-inch buffer. If water levels fall below that, the system shuts down. It’s a safeguard.” That’s also why the DEP monitors the situation for any negative impact. “They want to ensure that the aquifer is protected and an environmental balance is maintained.”
Pierini says the true value of the system won’t be realized until the next drought, but “indications show that all water-quality standards for reuse will be met.” Nevertheless, he deems the project a success by virtue of the HOA’s “foresight,” adding that “green lawns instead of brown will be the proof in the pudding.” He hopes the project will be a paradigm for the future, pointing out that it was recognized with a New Jersey Governor’s Environmental Excellence Award in 2006 for clean and plentiful water by demonstrating that it supports the state’s goals for sustainable water resource management.
“I wish we could retrofit other communities,” Pierini reveals. “Unfortunately, economics prohibits that. But I’m hoping this opens ideas to other communities.”
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Photo: Buchanan |
| Lagoons like this one act as a filter for the homes in the Homestead at Mansfield community. |
Not everyone hopes the same thing. Environmentalists believe reclaimed water opens the door to more development and potential contamination of groundwater. In an Associated Press article, Jeff Tittel, executive director of the Sierra Club’s New Jersey chapter, says use of reclaimed water on lawns could lead to a buildup of chemicals and fertilizers leaching into the aquifer, which supplies drinking water for the area.
The bigger picture, in his mind, is that reuse water could become the solution to water supply, encouraging even more development, which inevitably leads to more pavement that keeps rain from soaking into the aquifers. Instead, he suggests planting more native grasses that require less watering. He does support the use of reclaimed water for cooling power plants and flushing toilets in large buildings, adding that putting it back into the environment through lawn watering “doesn’t make as much sense.”
There’s not much cause for alarm in New Jersey because of an abundant water supply that usually makes recycling water too expensive to serve as a viable alternative. It worked for Homestead at Mansfield, thanks to the grant and the timing, but it won’t work for every application. Nevertheless, Lawrence says there’s been a lot of interest in what the HOA is doing, even though it has yet to use the system. “We’ve gotten a lot of attention—and we expect a lot more in about a month when we go online.”
Residing in Indianapolis, IN, Lori Lovely writes authoritatively on transportation and technical subjects.
OW - January/February 2008
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