Considered the nation’s first green residential high-rise, the Solaire in Manhattan, New York City, has garnered attention from around the world since it opened in 2003. The 293-unit in Battery Park City has received LEED Gold certification because of its broad range of environmentally-friendly amenities. In addition to solar energy, roof gardens and centrally-filtered air, the Solaire boasts another unique green feature — the nation’s first residential wastewater reuse system in an urban high-rise.

Nestled in the basement of the apartment building is its own, self-contained wastewater treatment plant. The system treats and recycles the building’s sewage for reuse in toilet flushing and HVAC cooling. It also supplies reclaimed water to a neighboring apartment building and provides subsurface irrigation to adjacent Teardrop Park. Designed by American Water’s Applied Water Management Group, the system relies on a state-of-the-art membrane bioreactor that uses microorganisms to breakdown waste. The mini-plant can treat and recycle as much as 25,000 gallons per day (gpd) — but the entire treatment system, including storage tanks that hold the treated water, occupies an area just greater than 2,000 square feet.

The Applied Water Management Group handled all aspects of the wastewater treatment system, including design, installation oversight and project management, as well as ongoing maintenance and operations. The project required the team to apply creative planning in order to build a “smart” treatment system that could respond to changing needs. For example, the system produces and supplies only the amount of water that is needed for daily building usage. If demand is low, it processes less water; if demand increases, the system has the ability to increase the capacity of wastewater it treats. Excess wastewater flows through a feed tank to the public sewers. Valves are installed on the building sewer lines to bypass the treatment system and send all wastewater to the street sewer, if it’s not needed for recycling at the Solaire.

Process

1. An aerated feed tank is the intercept point to divert flow to the plant and street. Wastewater is pumped from this tank to the next treatment unit,
2. A collection tank and trash trap removes plastic and other solids including grease.
3. Wastewater then enters the bioreactor, which contains active bacteria used to consume or digest the biodegradable waste products in the wastewater. The bioreactor contains two chambers: the anoxic, which operates with very low air; and the aerobic, which is completely aerated. Different kinds of bacteria thrive in each environment; pumps then draw the mixture through spaghetti-like membranes that filter the mixture, separating the treated water from the bacteria.
4. Treated, filtered water passes through an ultraviolet disinfection system that kills any pathogens still present in the treated wastewater.
5. An ozone generator removes any traces of color and remaining pathogens.
6. Water flows to storage tanks, which serve as reservoirs for treated water. The water is ultimately reused to flush toilets and as makeup water for the building’s cooling towers.

Engineers designed the reuse system to be highly automated with remote alarm and monitoring capabilities. A programmable controller takes readings of flow rates and oxygen levels to monitor overall system performance. An operator is assigned to check the system twice a week.

In addition, the water reuse system includes a separate mechanism that collects rainwater and stores it in a 10,000-gallon tank, also in the basement of the Solaire. The water is run through a sand filter and chlorinated to meet New York City requirements. The stormwater is then processed through a reverse osmosis unit (to remove any harmful salts) and used to irrigate two planted, green roofs on the 19th and 28th floors, reducing the need for city-supplied potable water.

Results

The Solaire has delivered outstanding results on all of its green initiatives. As a building, it consumes 35 percent less energy than a similar building designed to New York State’s code requirements. It consumes 50 percent less water than comparably sized New York City apartment buildings. Its innovative water reuse solution reduces the amount of potable water that is taken from the city’s water supply, while saving the energy needed to pump wastewater into a city treatment facility.

The use of multiple treatment features enabled the Solaire to obtain all of the necessary LEED Water Efficiency Credits to qualify for financial incentives offered by the New York City Department of Environmental Protection Comprehensive Water Reuse Program. By reducing potable water consumption by at least 25 percent, the building became eligible for a corresponding 25 percent reduction in water and sewer charges. Implementation of the reuse system and water conservation measures, along with compliance with Battery Park City Authority’s Green Guidelines, allowed the Solaire to qualify for New York State Green Building tax credits.

The Solaire stands as a leading model of environmentally sustainable living — one that continues to inspire additional projects. American Water is expanding its creative water reuse approach with four similar projects in the Battery Park neighborhood.

The Solaire was the winner of ED+C’s Excellence in Design: Multi-Use Residential category in 2004.

The Solaire

LOCATION: NEW YORK

TYPE OF PROJECT: DESIGN-BUILD-OPERATE, RESIDENTIAL HIGH-RISE

INITIAL SERVICE DATE: 2003

SIZE: 293-UNIT BUILDING

POPULATION SERVED: 750

WASTEWATER TREATMENT SYSTEM SIZE: 25,000 GPD TOTAL; 9,000 GPD FOR FLUSHING, 11,500 GPD FOR COOLING TOWER MAKE-UP, 6,000 GPD FOR IRRIGATION

PROJECT TEAM (WASTEWATER TREATMENT SYSTEM): AMERICAN WATER’S APPLIED WATER MANAGEMENT GROUP

Green Building Materials

• Concrete block containing fly ash.
• Shelve board containing saw dust.
• Photovoltaic panels made with recycled computer chips.
• Hardwood floors and cabinets that are FSC certified.
• Low-VOC paints and adhesives.
• ENERGY STAR appliances.
• Non-toxic and recycled material-base rugs.
• Compact fluorescent lamps.