Brief summation of listed presentations:
G. Sherrell - Dry Dock Pollutants, short term and long term solutions
Puget Sound Naval Shipyard is in the
process of significant waste reduction and source encapsulation programs. Sherrell identified short and long term goals of their program.Short Term methods to reduce drydock pollutants
- sweeping - poor results, particles too small
- vacuuming - works only if the floor is dry
- fancy collection and dispersal - very very expensive
- source containment and encapsulation.
Sherrell explained "source containment and encapsulation is the key to reduction of short term drydock pollutants. One of the drydock's best technologies is an enclosed hydroblasting unit that blasts the ships' hull
with no contaminants escape to outside air and 100% recycling of water.
Long Term method to reduce drydock pollutants
Watershed Approach
- Change "end-of-pipe" mentality. Promote legislation changes to regulate based on environmental risk analysis of the entire watershed. The Watershed Approach brings the entire picture of all pollutant effects and sources into the picture. Allow watershed trade-offs to shipyard in exchange for valuable environmental benefits to another portion of the community.
Contact: Jerry Sherrell -
sherrellg@psns.navy.mil
B. Kura - Minimization and Treatment of Shipyard Wastewater
Key concept Kura presents is the critical problem of
the variability of the wastewater stream. Because source pollutants are widely variable, treatment is difficult. Reducing source pollutants (in operations) is the key to keeping treatment and treatment costs to a
minimum.
Many treatment options are available, but keeping the sources of pollutants down by changing operational methods is the best option. Overall cost reduction will be achieved when we consider the expense of
treatment. Less treatment equals less cost and more environmental benefit.
Doug Randall - Environmental Enclosure systems in Canada Navy drydock
Faced with new environmental directives
to cut down airborne and waterborne discharges at drydocks, Randall determined to find cost effective methods without sacrificing environmental goals.
Designed enclosed syncro-lift using simple and available technologies
such as enforced tarping and plywood supported by strut system. Also developed water tight blocks for hydroblasting with recapture of water.
Combated severe climate issues of Halifax harbor, particularly high winds against
the supported ship in the dock. System passed storm with 80 knot winds - no problems to enclosure or ship. Total refit cost of capture and enclosure system approximately CAD$200,000.00
Contact Doug Randall:
drandall@fmfcs.hlfx.dnd.ca
Katherin Ford - Zero discharge Wastewater Treatment Plant
Puget sound is a large Naval shipyard facility developing
wastewater treatment changes, as mentioned above. Ford's goal was to eliminate excess hazardous sludge by reducing the amount of dissolved metals in the treatment stream.
Ford used technologies to precipitate or pull out
metals of little concern to better deal with main concern metal, dissolved copper.
Puget Sound established a system of selective recovery of certain contaminant metals. The current modified system can treat 30,000
gals in 24 hour batch process. Ford is working on issues of chromium and other difficult metals.
Contact: Katherin Ford:
fordkh@nfesc.navy.mil
