Re: National Stakeholders' Forum on MNA Report

[Tony Chenhansa <tonyc@cpeo.org>]

Forwarded from CPEO's Military Newsgroup

From: "Whitten, Rodney, Mr, SanFAFCEE"
<Rodney.Whitten@SANFAFCEE.brooks.af.mil>
Organization:  AFCEE
***************

Believe this statement is misleading

              "CZ requires a showing before monitored natural
attentuation is
              permitted: either that source removal has been
              accomplished and cleanup has reached asymptotic levels
              or that a cleanup is impracticable or that the "burden" of

              cleanup is disproportionate" to the benefits.".

Monitored Natural Attenuation is allowed as an active remedy without
using
section III.H of 92-49 (CZ).  For example, Natural Attenuation has been
the
final cleanup method of thousands of gas station leaks as well as many
other
sites.  CZ would be utilized only if convention cleanup (source removal,
pump
and treat, SVE, Bioventing and natural attenuation) has not been
effective at
reaching the water quality objectives (WQOs).  Most likely the trigger
for CZ
would be the amount of time (because of quanity of mass and geologic
conditions) that it would take for NA to be reach WQOs in the case of
petroleum discharges.  Geologic conditions and long-lived contaminants
could
be another.  A containment zone could be combined with a down gradient
pump &
treat system, if necessary for plume containment, for a contaminant that
is
not accessible (ie fractured bedrock), but will continue to leach over
the
years.

Rod Whitten