Memo/Enviromental review of Proposal•
AUG 03 '8 10 :47 B.A.LIESCH ASSOC.
To: City of Hopkins
BRUCE A. LIESCH ASSOCIATES, INC.
HYDRQGEOLQGISTS • ENGINEERS ENVIRONMENTAL SCIENTISTS
3020 Harbor Lane • Minneapolis. MN 55447.612 559.1423 • FAX No 559-2202
• MEMORANDUM
From: John C. Lichter, P.E.
Bruce A. Liesch Associates, Inc.
P. 2 /4
Date: August 3, 1989
Subject: Environmental Review of Proposed Hennepin County Ash
Storage Facility - 320 Washington Avenue South, Hopkins,
MN 55343
Liesch Associates has been retained to conduct an environmental
review on this proposed project in conjunction with the zoning
application made by Hennepin County to the City of Hopkins dated
July 21, 1989.
Documents reviewed by Liesch include: the zoning application, a
permit application for construction and operation of a temporary
storage facility made to the Minnesota Pollution Control Agency
along with attachments A I to the application.
A visit to the facility was made on July 18, 1989 to assess
existing conditions on site and proposed improvements noted in the
application provided by Hennepin County. The facility proposed is
located in the central portion of Hennepin County Bureau of Public
Service storage facility located at 320 Washington Avenue South in
Hopkins, HinnPsnt,e. The site is fenced by Oeven foot high chain
link fence with controlled access at the scale house located at the
northeast corner of the site. The ash storage facility itself is
an existing salt storage facility building enclosed on the east,
north and west sides and covered with . a roof and is approximately
160' X 140' in size. The capacity of the facility is estimated to
be approximately 20,500 tons. This site is to serve as a temporary
storage facility while the ash landfill site which will serve the
facility is completed.
Construction is anticipated to occur by December, 1989. The
interior of the facility is bituminous surfaced (4 inch minimum)
and is bermed on three sides with the open end on the south end
which is approximately level. The flatter portion of the asphalt
surface is sloped towards the southwest corner where a leachate
collection system is proposed to be constructed by the County. At
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AUG Q3 '89.10 :48 B.A.LIESCH ASSOC.
Page Two
P. 3/4
this time, the south end of the building is proposed to remain open
and leachate collection system construction details have not been
provided as part of this application to, date. The only type of
waste to be received at this facility is ash residue from the HERC
facility.
There are no floor drains in the proposed storage site. Runoff
from the vicinity of the facility is diverted to a sump drain
approximately 150 feet from the southwest corner of the salt
storage building in a retention pond on the southwest portion of
the site. Topographi maps provided by the County indicate that
run on into the storage site is not likely and further, the County
is proposing to construct an asphalt berm on the south end of the
facility to prevent any possibility of run on into the storage
facility or runoff of leachate from the southwest corner of the
facility out into the environment. However, specific details of
this berm construction are not included in the current application.
The anticipated operational period of this facility is to start on
approximately August 15, 1989 and close by December 15, 1989.
Analysis of Existing Information
The information submitted to date by Hennepin County includes the
following items: the zoning application, the Minnesota Pollution
Control. Agency permit application, the facility start -up waste
acceptance schedule, the MPCA temporary ash management program, the
County's contingency action plan, the County's accident prevention
program, the emergency response plan for preparedness and
prevention, the MPCA emergency planning fact sheet, the HERC
facility description, plat maps and topographic maps in the general
facility of the site, andconstuction drawings of the facility
itself.
The review conducted by Liesch Associates assessed land, air,
water, noise and public health and welfare issues. Based on the
review conducted to date, the following issues appear to require
addition information, consideration or resolution prior to the
issuance of a conditional use permit by the City of Hopkins:
1. Site operating Schedule - xf the Medina facility comes on line
prior to December, it is possible that the facility can be
operated and closed within the proposed schedule of August
15th through December 15th, 1989. However, if waste material
continues to be hauled into the site during the month of
December at the rate of 15 to 20 truckloads per day, or even
less, it will take the County a significant amount of time to
load out ash from the site. It then appears that the closure
date of December 15th is not realistic and requires
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AUG' Q3 '89 .18.49 B.A.LIESCH ASSOC. P.4/4
Page Three
modification. Further, the City may wish to place hours of
operation restrictions or other restrictions limiting the
amount of traffic during the loadout period. This may have
the effect of extending the time needed for closure.
2. Since the southern end of this existing salt storage building
is not enclosed, it is possible that as the site filled,
during high periods of wind, fugitive dust could be omitted
from the facility. It seems.prudent to suggest that. the
County provide mitigative measures through temporary or
permanent means during weather conditions when this situation
may exist.
3. Leachate Collection - .A description of the leachate collection
berm construction and leachate retention system is not
provided. Construction details and liner. efficiency
calculations and /or evaluations should be provided. and
assessed prior to issuing the conditional use permit. Should
the proposed system not meet UPCA efficiency standards,
groundwater monitoring should be considered.
4. Contingency Planning - Although several contingency planning
documents were attached to the application, a specific
emergency coordinator and two designated alternates should be
provided in Attachment C within the application provided by
Hennepin County to HPCA. A specific point of contact for the
City of Hopkins or other regulatory bodies would then be
available.
5. If by some circumstance, the Medina facility is not ready by
December, 1989, what backup plan or contingency plan will be
County implement to close the facility during the scheduled
time?
6. Although not described specifically in the application itself
is understood from personal conversations with representatives
of Hennepin County that a sprinkling system will be used to
wet the ash periodically to prevent dusting within the
facility itself. In view of this fact and also that ash
material brought out to the site will be saturated do to the
nature of collection at the HERC facility, it is possible that
if the ash remained on site during the winter months, it will
be frozen. The question then comes to mind that how does the
County anticipate handling ash in this state and will freezing
of the ash prevent or effect the loadout schedule of ash from
the facility.
All of these items of concern have been forwarded to Hennepin
County so that they may address them at the Planning and Zoning
Commission meeting on August 8, 1989.
HD1 :HOPKINS