Recycling Water, Saving Dollars

Co-ops and condos may be flushing money down the toilet. For as long as anyone can remember water and sewer charges in New York have been relatively low, while consumption and discharge volumes have been high. All that is about to change. By April 1, the New York City Department of Environmental Protection (DEP) will submit to the city’s Water Board new proposed rates that will provide significant incentives for building owners and managers to reduce both water consumption and sewage discharge.

Low-flush toilets and restrictive showerheads will help a little, but there are now options for much more comprehensive solutions. Several new residential buildings in the city have been designed with multiple piping systems that collect wastewater for treatment and recycling on site. Graywater is effluent from sinks, tubs, and laundries. It is generally low in germs and low in biomass, but usually high in soap. Blackwater is from toilets, and is obviously high in germs and biomass, and low in surfactants. A combined stream, as found in the vast majority of residential wastewater pipes, is considered blackwater.

Currently, there are not yet any co-ops or condos in New York that have retrofitted these systems. The cost-savings will be significant, but are not yet there. But the coming changes in water and sewer rates, as well as the market advantage of having an environmentally friendly building, make it the business of every building board to consider its wastewater options. Systems could be retrofitted in stages. Also, several adjacent buildings could install a joint system, or a building could connect to the system of a business nearby. In either case, capital, construction, and operating costs would be reduced by an important margin.

“The mayor has made green buildings a mission,” says Charles Sturcken, director of public and intergovernmental affairs for the city’s Department of Environmental Regulations. “We are looking at numbers that make it worth people’s while [to reduce water and sewer loads].” After the Water Board publishes the proposed rates in April, there will be a public comment period. The final rates will be adopted on May 1, and take effect July 1.

“A graywater or blackwater system is a phenomenal way to reduce water use,” says Christopher Ward, DEP commissioner. “The department is modifying prices for water and sewer use, and we are seeing plumbing code changes.” Ward adds, “the water-in, [water-]diverted, [water-]used, and [water-]saved calculations are fairly straightforward, but we need to validate the calculations. We are putting together a pilot project on the proposed new rate structure.” DEP has given allowances in the past for buildings that reduce water and sewer loads, but that has been done on an individual basis. The current sewer charge is set at 159 percent of the water charge.

The simplest system would treat wastewater and use it for irrigation, cooling systems, or laundry. It is also possible for reclaimed water to be reused in the residential units. Most of those options have been tried in one form or another, at various residential buildings around the country. Costs of water treatment systems vary widely. Equipment is rated by gallons per day of capacity. Most urban buildings can expect to pay from $20 to $30 per gallon per day.

But lower Manhattan does have the swimsuit model of green buildings: the Solaire, which opened July 2003 at Battery Park City and, as of early January, was 95 percent rented. The Albanese Organization is developer and co-owner of the property and brought together some of the top water-reuse firms in the country for the project. “I don’t see water reuse as a viable retrofit if that were the only alteration,” says Russell Albanese, president. “But in conjunction with other work, there would be an economy of scale.” The Solaire uses a blackwater system, which Albanese calls “a tried-and-true system. The system uses natural biological [treatment] in a relatively small space. It is up and running well.”

Cosentini Associates were consulting engineers for mechanical, electrical, and plumbing at Solaire. Scott Ceasar, vice president with Cosentini, says retrofitting a water reuse system would be easiest for an industrial-to-residential gut and rebuild, but for extant structures, he is a fan of stormwater recovery. “From rooftop to tank, it requires only slight treatment, and can knock off irrigation costs. That means a payback in less than 2.5 years.”

The real stumbling block to residential water reuse has not been co-ops and condos, but rather individuals. “The fear is not professionally managed buildings,” says Edward Clerico, vice president/strategy for Applied Water Management of Hillsborough, N.J., which designs, installs, and manages treatment equipment. “The fear has been the handy-dandy homeowner who would hook up something wrong. Actually, direct water reuse systems have been very popular in shopping centers and schools. The Solaire broke the hurdle on direct residential reuse.”

Clerico says the next important frontier for residential water reuse is for laundries – a perfect application for condos and co-ops. A graywater laundry system would significantly reduce both potable water draw and wastewater load. It would also eliminate the need for installing much new piping. The laundry is also likely to come out cleaner, because treated water is usually free of minerals that make wash water hard.

There is little or no cost for collection systems, says Herschell Winfrey, manager of engineering for standard systems at Zenon Environmental, based in Ontario, which designs systems. “The collection systems are the same as have been in use for a hundred years. The task with retrofitting [a water reuse system] is finding somewhere to put it. An average-sized residential building needs about 24 feet by 40 feet. After that, you’ve got the plumbing. Irrigation and cooling systems are easier piping. And laundry would be an ideal reuse. We have quite a few commercial laundries. The first one was in 1994, so that is a decade of operational experience.”