report series d: groundwater...
TRANSCRIPT
Since 2004, the Pebble Par tnership has worked with a number of Alaska-based consultants to manage an ongoing program
of groundwater hydrology data collection and analysis at key locations throughout the Pebble Project area. Groundwater is
water found beneath surface in overburden pore spaces and in the fractures of bedrock formations.
Companies contributing to Pebble Project groundwater hydrology (or hydrogeology) studies between 2004 and 2007 include:
• Water Management Consultants Inc.; • Paug Vik Development Corp.;
• SLR Alaska; • Bristol Environmental & Engineering Services Corp.; and
• HDR Alaska; • CH2M Hill Inc.
Groundwater hydrology studies are designed to characterize the groundwater regime in the Pebble Project area, including
water quantity, flow rates and flow directions. The study also includes an evaluation of the interaction between groundwater
and surface water.
Pre-Permitting Environmental/ Socio-Economic Data Report Series
Report Series D: Groundwater Hydrology
1,310,000
1,310,000
1,320,000
1,320,000
1,330,000
1,330,000
1,340,000
1,340,000
1,350,000
1,350,000
1,360,000
1,360,000
1,370,000
1,370,000
1,380,000
1,380,000
1,390,000
1,390,000
1,400,000
1,400,000
1,410,000
1,410,000
1,420,000
1,420,000
1,430,000
1,430,000
1,440,000
1,440,000
1,450,000
1,450,000
2,09
0,00
02,
100,
000
2,11
0,00
02,
120,
000
2,13
0,00
02,
140,
000
2,15
0,00
02,
160,
000
2,17
0,00
02,
180,
000
2,19
0,00
02,
200,
000
\\Manu\projects\Pebble\reporting\2008 Pebble Data Report\Site Plan.mxd
Legend
Canada
ARCTIC OCEAN
PebbleProject Area
GULF OF A LASKA
Russia
BERING SEA
0 10,000 20,000 30,000Feet
Alaska State Plane Zone 5 (units feet)1983 North American Datum
Date: June 16, 2008
Author: WMC-LC
1:150,515Scale
Project No: 7126
Version: 1
General Deposit LocationWetland Piezometer (WL)Monitoring Well (MW)Piezometer (P, GH, I, M)Pumping Well (PW)
WatershedNorth Fork Koktuli RiverSouth Fork Koktuli RiverUpper Talarik Creek
Pre-permitting Environmental/Socioeconomic
Data Report Series
Report Series D: Groundwater Hydrology
Site Plan
0 3,000 6,000 9,000Meters
LakesRivers50-ft Contour Interval
Pebble Project groundwater hydrology data collection occurred at 259 monitoring wells and piezometers at 196 sites throughout the South Fork Koktuli River, North Fork Koktuli River and Upper Talarik Creek watersheds.
levels are recorded hourly in some wells. Piezometers are constructed in the same way as monitoring wells but are used to
measure only groundwater levels.
Elements of the Pebble Project groundwater hydrology study include:
• characterization of the subsurface geology to identify fine-grained materials (silts and clays) versus coarse
grained materials (such as sands and gravels);
• 94 rising and falling head tests to measure hydraulic conductivity or the rate at which soil or rock allows
water to flow;
• seven pumping tests where one well is pumped and several near-by wells are monitored for changes in
water level;
• hourly and monthly groundwater elevation monitoring;
• a seep inventory of groundwater discharges to surface (including location and size classification) and flow-
rate monitoring at selected seeps throughout the study area.
The information being released as par t of the Pebble Par tnership’s Pre-Permitting Environmental & Socio-Economic Data
Repor t Series in June 2008 includes data and associated figures gathered between 2004 to early 2007 and is organized into
the following data groups:
• well, piezometer and drillhole locations; • pumping tests;
• monthly groundwater elevations; • seep inventory;
• hourly groundwater elevations; • seep flow rates.
• response tests;
Additional hydrogeology investigations are planned for 2008.
The data from the 2008 field program will be available in 2009.
Complete copies of the groundwater
hydrology data reports released as
part of the Pebble Partnership’s
Pre-Permitting Environmental &
Socio-Economic Data report
Series are available online at
www.pebblepartnership.com.
The study area for Pebble’s
groundwater hydrology program
includes the North Fork Koktuli River
watershed, the South Fork Koktuli
River watershed and Upper Talarik
Creek watershed. The study included
the installation of 259 monitoring
wells and piezometers at 196 sites
throughout these watersheds.
Monitoring wells are utilized to collect
groundwater samples and monitor
groundwater levels. Groundwater
Drainage
South Fork Koktuli
North Fork Koktuli
Upper Talarik Creek
TOTAL
Piezometersand
MonitoringWells
160
65
34
259
Piezometerand
MonitoringWell Sites
113
42
20
175
MonitoringWells
24
8
6
38
MonitoringWell Sites
12
5
4
21
Table 1: Summary of Monitoring Wells and Piezometers by Drainage
Hydrogeology studies provide valuable input to the Par tnership’s engineering team, in par t by identifying potential
changes to the groundwater regime resulting from construction, operation and closure of future mine development.
A comprehensive understanding of groundwater conditions will allow project engineers to design a project that minimizes
groundwater impacts and incorporates measures to mitigate residual effects.
Groundwater characterization is being under taken at multiple locations throughout the project area to identify optimal
locations for various mine facilities, including the mill, tailings storage area and other mine components. Project facility design
and location will also be substantially influenced by related environmental considerations – including effects on surface
water, fish habitat and wetlands.
Program Overview: Study Area