APPCOR13302

• Permit No: C1996084
• IBM Index Class Name: Application Correspondence
• Doc Date: 2/12/1996
• Doc Name: BASELINE STUDIES & PERMIT APPLICATION PREPARATION FOR LORENCITO COAL PROJECT LAS ANIMAS CNTY COLO
• Media Type: D
• Archive: No

WATER RESOURCES STUDY PLAN
PURPOSE AND OBJECTIVES
The purpose of the baseline hydrology
work plan is to establish surface water,
spring and seep, and ground water
monitoring locations, schedules, and
procedures to obtain necessary environmental
baseline information that will provide
technical basis for the description of the
existing hydrologic environment on or near
the Lorencito Coal property site. The
description and subsequent impact evaluation
will be submitted as pazt of the permit
application to the CDMG for the
development of the project. This information
is required by Rule 2.04.7 of the CDMG
regulations.
The program defines the surface and
ground water hydrology of the proposed life
of mine area concentrating on the five year
permit area.
HYDROLOGIC OVERVIEW
The water resources study plan will
characterize the quantity of water in the
surface and ground water regime. Water
quality will be characterized to establish
baseline conditions. Current water uses will
be documented.
The Lorencito project is located on
tributaries to the Purgatoire River. Surface
water monitoring will establish the period
and range of flows on watersheds which aze
projected for disturbance.
There aze six aquifers of interest for this
project; the alluvial aquifer, the overburden,
the Ciruela coal, the interburden, the
Primero Coal, and the underburden aquifer.
The major surface water features to be
evaluated include Lorencito Canyon and side
canyons and the potential spring and seep
sites in the area.
The hydrologic impact evaluation will
examine short- and long-term impacts to
surface and ground waters of the area.
Short-term impacts to surface waters will
include potential changes in sediment
loading, water quality, and changes in storm
hydrographs and flows. Short-term impacts
to ground waters will include dewatering of
the coal aquifer and potential dewatering of
the overburden aquifer for the underground
mines. The surface mine may interrupt the
recharge and discharge zones of the coal
aquifer and modify the water chemistry.
Predictions of impacts to the hydrologic
balance will yield supplemental information
useful in the design of the mining operation.
For example, estimates of aquifer drawdown
will yield volume required for the
establishment of mine water dischazge ponds.
Long-term impacu to surface waters will
predominantly be associated with changes in
water chemistry and salinity loading,
particularly in conjunction with the refuse
disposal area and the surface mine. A small
backfilled spoil aquifer may develop at the
surface mine which will modify flows as well
as water quality in the downstream
drainages. Long-term impacts to
groundwater will be addressed by discussions
about the re-establishment of the
potentiometric surface and the water quality
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