Greening Mass Transit & Metro Regions: The Final Report - MTA

Water Management
Water resources management, conservation, and protection
"As one of the world's leading
transportation authorities and one of New
York City's major water users, the MTA is
uniquely positioned to set a global standard
for innovative water resource management.
By significantly reducing its use of potable
water, guarding against future flooding risks,
and making beneficial use of ground and
storm water to run its operations, the MTA
can become a sustainability leader while
addressing the challenges of a warming
climate and saving the authority and its
customers money."
– Alex Matthiessen, Hudson Riverkeeper
and president, Riverkeeper
Chair, Water Management Group
While the public is unlikely to associate the MTA with water
issues, water management plays a distinct role in the
authority’s sustainability efforts. Given the scale of its
operations, the MTA is a major consumer of the metropolitan
area’s potable water. Its daily operations also include pumping
out groundwater to keep its track and tunnels dry. In addition,
many MTA properties and rights-of-way border wetlands and
waterways that serve vital ecological functions and that
should be protected. The MTA must also manage wastewater
and runoff from its properties and operations during intense
storms, when flooding can both disrupt service and endanger
local water quality by overwhelming sewer systems.
At present, MTA operations are estimated to use roughly
2.6 billion gallons of potable water per year, of which a large
share, estimated between 1.2 and 1.4 billion gallons, is used
in the flow process to cool NYCT subway system transformers.
Washing vehicles also accounts for a significant share
of the MTA’s overall water use. The Commission looked at
ways to reduce the MTA’s potable water consumption,
including expanded use of greywater and rainwater for
nonpotable needs such as washing vehicles. A preliminary
study undertaken by the Commission indicates that, in
addition to incremental conservation measures, there are
Left: A rainwater collection system on the roof of the Corona Maintenance Shop
in Queens drains rainwater into a 40,000-gallon underground storage tank that
supplies water to a subway car washer.
a number of plausible options for significant reduction in
the MTA’s use of potable water. Depending on which mix
of programs and technologies proves feasible, the MTA
should be able to reduce its use of potable water by up
to 75 percent by 2020.
Research conducted by the Commission concluded that
many transportation agencies place a relatively low emphasis
on water-reduction targets. By significantly reducing its
water consumption, the MTA would be viewed as an
industry leader in sustainability. Globally, water is increasingly
understood as a precious but diminishing resource,
vital for life and economic prosperity.
An important first step will be to implement consistent,
systemwide water-metering and submetering at MTA facilities,
which the Commission has cited as a top priority in its
Interim Report. Conservation measures would then include a
range of strategies, from staggered vehicle wash schedules
to harvested rainwater and water-saving fixtures in public
stations. Water management also plays a large role in facilities
design. Among the green features of the MTA’s LEEDcertified
Corona Maintenance Facility is a 40,000-gallon
rainwater capture system to supply water for washing
subway cars. Several other MTA facilities operate vehicle
wash systems using recycled greywater to reduce strain
on potable water systems, while water-control innovations
such as green roofs are part of the design of MTA facilities.
One of the more intriguing water management ideas involves
the use of groundwater. The MTA currently pumps some
8 million gallons of groundwater per day out of its subway
tunnels on a dry day and up to 13 million gallons per day
during storms. Once regarded as a nuisance, groundwater
has a number of potential uses. From a global perspective,
this water should be seen as a valuable resource latent in
MTA properties. Possible uses include thermal exchange
heating and cooling in MTA facilities or nearby buildings.
The Commission is currently identifying potential uses near
current groundwater pump sites.
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