The disposal options for spent fountain solution is dictated by
the waste water disposal options available to a printer. In most
cases, printers discharging to a POTW will be allowed to discharge it
without pretreatment requirements. Some POTWs will set a limit on the
amount that can be discharged. For example, the MWRA in Boston only
allows a printer to discharge 55 gallons of spent fountain solution per
month. Many other POTWs will regulate by setting parameters on specific
constituents like oil/grease, copper, BOD, COD, and flammability. The
printer is expected to meet these parameters.
The challenge for printers is when they discharge to a septic system or
directly to a waterway. In the case of septic systems, discharges of
industrial waste are prohibited. Direct discharges to waterways are
acceptable only if a NPDES permit is obtained and the printer performs
extensive pretreatment. Under these two scenerios, the printer is forced
to send the fountain solution off-site for treatment and disposal.
The options for sending it off-site is governed in part by RCRA
requirements. If the fountain solution is determined to be
a hazardous waste and the printer is shipping it off-site, then the
fountain solution would have to be treated by a permitted TSDF. The only
fountain solution that would be classified as hazardous would be one
containing more than 5% isopropyl alcohol. It would have a flashpoint
less than 140 degrees F. Fountain solutions containing substitutes would
not be classified as hazardous.
In order to cut the costs of off-site disposal which can range from
$2.00-3.00 per gallon, some printers have installed evaporation units to
reduce the volume sent. Other printers have installed in-line and
off-line filtration systems. These systems extend the life of the
fountain solution and some printers have reported that they have doubled the
life of their fountain solution. In one instance, a printer has installed
a centralized waste water collection and distillation system. This has
eliminated all industrial waste water discharges to their POTW.
Unfortunately, they do generate still bottoms that must be sent off-site
for treatment and disposal.
If you need any more information, please contact me.