the plastic covering that would expose untreated wood to marine borers. For load-bearing piling
this would not likely be required.
2. Environmental Risk. Where a project involves the installation of a large volume of
treated wood in an area of low water volume and limited flushing action or where there is any
reason for environmental concern, a site specific evaluation should be completed to assure an
acceptable level of environmental risk. Such a proactive stance may preclude adverse action on
the part of potential environmental regulators. The cost of such an evaluation should be added on
to any economic analysis when comparing the costs of different materials. Consideration should
be given to the use of software developed for the Western Wood Preservers Institute (WWPI)
that is designed to establish the level of environmental risk in a variety of situations.
The WWPI, in response to environmental challenges to its products has sponsored
research designed primarily to promote the responsible use of treated wood. To that end, risk
modeling research that estimates the actual quantities and fate of preservatives in the marine
environment at specific locations has been completed. The idea being that in some locations, the
actual environmental risks are small and do not warrant restrictions, while in other locations, the
use of treated wood has a higher environmental risk and should be restricted. In some cases, it
appears that local regulators are taking action against perceived risks not actual risks.
3. Treatment Certification. Use third party inspections in all cases to certify
compliance with treatment standards as required by NAVFAC guide specifications. All
preservative-treated wood, but especially creosote products shall be inspected visually to ensure
that there are no excessive residual materials or preservative deposits. If the material is not clean
and dry it must be rejected because of environmental concerns.
During inspections at treatment facilities, one can assure proper fixation of salt treatments.
Arsenical salts are "fixed" or attached in its insoluble form to the wood. If this is not properly
done then the salt can leach out of the wood adversely effecting performance and creating
unacceptable environmental risk. Improper "fixation" cannot be detected by visual inspections.
For chromated copper arsenate (CCA) treatments, the Chromotropic Acid test (AWPA Standard
A3-11) is an acceptable method used for evaluating fixation during treatment. For ammoniacal
copper zinc arsenate (ACZA) and ammoniacal copper arsenate (ACA) proper treatment
procedures that assures that the ammonia has evaporated are the only means of assuring that
proper "fixation" has occurred.
Unfortunately, proper fixation cannot be reliably determined by inspection at the end use
site. Some means of assuring acceptable leachability of newly procured arsenical-treated wood at
the end use site would be desirable.
Creosote is not "fixed" or attached to the wood. It enters into wood spaces and can
"bleed" or migrate out of the wood if mishandled or improperly treated. Visual inspection can
determine if this has occurred. A means of assuring excessive "bleeding" of creosote does not
occur after installation would also be environmentally sound.
4. Installation and Maintenance. Care in the handling and use of treated wood can help
to ensure personnel safety and environmentally acceptable, long-lasting products. Where the
cutting or boring of treated wood cannot possibly be avoided, field treatments must be prescribed