Re: [CPEO-MEF] 30 Year Feasibility Timeframe

[petestrauss1@attbi.com]

Steve:

I have two possible theories for a legal rationale for a 30 year time frame.

First, in RCRA the post-closure monitoring fund and plan for landfills is 30
years, although many landfills will have to be monitored longer than that.
I suspect that this is a convenient carry-over from that regulation.

Second, in risk assessments, 30 years is used for the exposure time in
residential exposure scenarios.  I think this is less likely.

Lete me know what you find out.

Peter Strauss
----- Original Message -----
From: <themissinglink@eznetinc.com>
To: "cpeo-military" <cpeo-military@igc.topica.com>
Sent: Monday, April 14, 2003 9:27 AM
Subject: [CPEO-MEF] 30 Year Feasibility Timeframe


> Can someone tell me the legal reasoning behind the 30 year time frame for
> these base closure environmental assessments?  At Yucca Mountain the
geology
> was assessed over a period of tens and hundreds of thousands of years
which
> seems appropriate given the duration of the toxicity.
>
> My issue is that Landfill 7, at the former Fort Sheridan, was created in a
> ravine along the bluffs of the North Shore along Lake Michigan.  The
bluffs
> are eroding at a rate of 20-25cm per year during the 130 year time frame
> studied by the USGS.  That is about 100 feet of bluff recession which will
> surely affect Landfill 7 over the next 100 years since the waste is right
at
> the edge of the bluff.  Even if the waste is set back the 150 feet of the
> bluff lateral distance(which is not a sure thing given the incomplete Army
> data on the landfill boundaries), the rest of the bluff will recess
leaving
> Landfill 7 as a jut in the lake.  This is assuming that the engineering
> controls are really going to be effective at stopping erosion along a
single
> point when no such stretch of bluff has ever been shown to be impervious
no
> matter what erosion controls have been put in place as referenced below.
>
> I found this interesting :
> http://pubs.usgs.gov/of/of94-255/docfiles/overview.doc
>
> "Between 1872 and 1987,  rates of bluff retreat from Wilmette to Waukegan
> vary from 10 to 75 cm/yr between discrete segments of bluffs [figure_3].
> The average rate of retreat for the entire area, however,  does not vary
> significantly between 1872-1937 and 1937-1987 and ranges from 20-25 cm/yr.
> No obvious correlation appears to exist between lake levels, rainfall,
> abundance of groins, and retreat rate.   Local variations in retreat rate
> do, however, correlate closely with lithologic variations.  Bluffs that
> contain lake-plain sand and silt have higher retreat rates than clay-till
> bluffs.  However, the bluffs  have little curvature across these
boundaries
> indicating that the variations average out over time, producing long- term
> parallel bluff retreat. (Jibson and Staude)."
>
> Also, from http://jglr.org/1994/num1/20_1_135-152.pdf
>
> Rates and Processes of Bluff Recession Along the Lake Michigan Shoreline
in
> Illinois-1994
>
> Randall W. Jibson and Jackson K. Odum
>
> U.S. Geological Survey
> Box 25046, MS 966, Denver Federal Center
> Denver, Colorado 80225
>
> Discussion and Conclusion
>
> ".........What are the human consequences of the 20-25cm/yr bluff
recession
> rates in this area?  Development in most of the area consists of
> medium-density single-family housing(large homes of fairly large
> lots)ranging in age from new to nearly 100 yr old.  Setbacks from the
bluff
> vary from almost zero to a few tens of meters.  If the regional retreat
rate
> prevailed everywhere(which it does not), then a house would need a 20-25 m
> setback from the bluff to survive 100 yr.  Few houses have such large
> setbacks.  Even though regional retreat rates are fairly constant, Figure
9
> shows that retreat rates vary substantially from place to place for a
given
> 50-100 yr period.  The retreat that a specific part of the bluff might
> experience in any 50-100 yr period probably  depends on several factors at
> that site and at nearby parts of the bluff: (1) the type and quality of
> shore protection, (2) the rate of retreat in the previous 50-100 yr
period,
> (3) the local lithology and geotechnical properties of the bluff material,
> (4) the width of the fronting beach, and (5) the geometry of the shoreface
> in front of the bluff.  Therefore, the data and conclusions from this
study
> are relevant for regional planning rather than site-specific engineering.
> Any planning for construction near the bluffs, however, must anticipate
some
> amount of bluff recession and stipulate sufficient setback to insure the
> integrity of structure for it's anticipated life."
>
>
> This would seem to indicate that the Army concept of protecting a single
> point against bluff-wide erosion is a fiction.  I guess it comes down to
> what the Army's requirement is for the stability of the engineering
controls
> after the thirty year time frame.  Is the time frame a yardstick to
measure
> geologic stability after which time the Army gets to walk away with the
> assumption that if the cap lasted thirty years then it will last forever?
> Or is the thirty years just some arbitrary number and the Army is still
> responsible to take corrective action when the erosion begins to disturb
the
> erosion controls?
>
> Steven Pollack
> www.familyjeweler.com/fortweb.htm
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> You can find archived listserve messages on the CPEO website at
>
> http://www.cpeo.org/newsgrp.html
>
> If this email has been forwarded to you and you'd like to subscribe,
please send a blank message with no subject to:
>
> cpeo-military-subscribe@igc.topica.com
>
>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~