New Jersey Transit
Initial Proposal
Proposal to USEPA for XL Pilot Program
by
Steven Jurow, Manager
Environmental Services Unit
NJ Transit Corporation
October 9, 1996
Issue
New Jersey maintains one of the strictest water pollution discharge control
regulations in the nation, imposing self-monitoring obligations, levying
mandatory fines on permittees for failure to maintain compliance
with the terms of their discharge permits, and delegating this enforcement
obligation to privately operated treatment plants which must themselves
meet the same strict requirements.
Even as discharge water quality requirements have tightened,
fresh water costs have been escalating at some 10% per year over the past
twenty years in the northeast (even more rapidly in the water-scarce south
and west); increasingly stringent federal requirements governing influent
water quality are anticipated to maintain or accelerate the rate of escalation
in the cost of fresh water well into the 21st century.
These two trends combine to make industrial water consumption and pre-treatment
a challenging arena, where each drop of water must be paid for twice:
once to buy it, and once to discharge it. In earlier times, dilution was
sometimes the solution, since fresh water costs were low. But with escalating
fresh water costs, and with the improvement of off-the-shelf filtration
and treatment technologies, on-site pre-treatment and re-use of industrial
water is becoming increasingly available, not to mention socially appropriate.
Like any vehicle maintenance operation, NJ Transit consumes a great deal
of fresh water in its bus and Tail maintenance facilities, for vehicle
body, engine and garage floor cleaning of petroleum contaminants. Under
New Jersey's strict regulations, this water must be pretreated at each
location prior to discharge, if the waste stream is to meet discharge
permit requirements. To reduce the volume of fresh water that must ultimately
be treated, NJ Transit has experimented with reduced-flow feed systems
that use less water at higher pressure. While reducing the amount of water
consumed by as much as two-thirds, this has had the side effect of increasing
pollutant concentrations in the resulting waste stream, necessitating
increasingly sophisticated filtration and/or chemical removal systems
to maintain compliance with discharge permit limits.
The challenge remains how to minimize the cost and consumption of fresh
water while still meeting waste water discharge permit requirements, at
reasonable cost and employing technologies which can be operated and maintained
by garage and shop floor personnel. With an eye toward a future when fresh
water is far more costly than today, NJ Transit has experimented with
a 100% industrial waste water reclaim system employing a series of filter
technologies now readily available to industry.
Initial results have been encouraging, and NJ Transit has incorporated
into its design for a new bus maintenance facility at Wayne, New Jersey,
the ability to be so equipped.
Proposal
NJ Transit has experimented at the pilot level with a cascading filtration
system configured to produce two qualities of re-use water, and to virtually
eliminate the need for fresh water for industrial cleaning activities.
The system employs Micro- and ultra-filtration, followed by activated
carbon and, finally, diffusion by reverse osmosis, to produce both a medium
quality wash water and a fresh-water equivalent rinse water. The system
configuration is shown in schematic in Figure 1. The system's anticipated
benefits in production are:
1. Reduction in the demand for fresh (city) water by 80%, to only that
needed to make up evaporative losses from the shop floor and vehicle bodies,
or to replace periodic purging of increasingly saline (salty) middle-quality
wash water.
2. Softening of water through reverse osmosis, reducing soap requirements
for all washing activities by approximately 90%.
3. Conservation of steam degreasing system boiler coils by the elimination
through reverse osmosis of hardness components (dissolved minerals) that
eventually foul this equipment.
4. Conservation of wash equipment components typically decayed by the
addition of water softening treatments that generally (ozone or chemical
softeners) assault the relevant metals, and which, through elimination
of dissolved minerals in the reverse osmosis step, are no longer needed.
5. Discharge of salty water only, well within even the strictest discharge
permit limitations for oils, suspended solids, and even metals, which
are removed by the reverse osmosis step.
Request for Funding Support
We intend to install a system of this design at our Wayne bus maintenance
facility now in construction, and scheduled to open in Summer 1997. The
costs of the system are approximately $150,000, installed, about twice
those of a simpler, ultra-filtration system that does not permit re-use
of the water, does not remove dissolved metals, and does not conserve
soap, wash system components, or boiler coils.
The system is unique in its use of reverse osmosis technology in support
of industrial cleaning activities rather than the more standard potable
water supply function. In addition, the system will demonstrate that with
modest initial capital investment relative to the available alternatives,
and employing what are now largely off-the-shelf technologies well understood
in the water supply and treatment profession, industrial water users have
real options to materially reduce their fresh water requirements while
easily meeting ever more stringent discharge water quality requirements.
The system NJ Transit installs at its Wayne bus maintenance facility should
produce data useful in determining the system's value in general application
across the vehicle maintenance industry, particularly bus, truck, and
major equipment maintenance facilities where such cleaning chores are
a routine function. We intend to collect water quality and water flow
volume data at each of the intermediate filter points, to better understand
what removal efficiencies are achieved at each stage of the process, and
whether further refinements can be made to either simplify or reduce the
cost of the system while still maintaining its effectiveness.
As the system is roughly twice the cost of what was budgeted for the facility's
waste water pre-treatment function, additional federal support would be
helpful in bringing this system on line more quickly, and with a view
toward demonstrating its value and application more broadly across equivalent
industrial uses.