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					Draft Environmental Impact Statement for Resumption of        DRAFT
Year-Round Firing Opportunities at Fort Richardson, AK




            United States Army Garrison ­

                        Alaska


                         Eagle River Flats
         National Pollutant Discharge Elimination System
                        Permit Application

                                     2007 Monitoring Report




                                         November 30, 2007




                                                              E-199
Draft Environmental Impact Statement for Resumption of                                           DRAFT
Year-Round Firing Opportunities at Fort Richardson, AK




                                Eagle River Flats NPDES Permit Application
                                      2007/Fifth Year Monitoring Report

                                                         Table of Contents



          A. INTRODUCTION                                                                   1

          B. CHANGES IMPLEMENTED IN THE 2007 SAMPLING PLAN                                  3

          C. SITE CONDITIONS REQUIRED FOR SELECTION OF SAMPLE DATES                         .4

          D. LABORATORY RECEiPT                                                             6

          E. ANALYTICAL METHODS                                                             6

          F.   DATA RESULTS                                                                  6

          G. STATISTICAL COMPARISON - HYPOTHESIS TESTING                                    8

          H. CONCLUSIONS FROM THE ANALYTICAL DATA                                           10

          I. RESULTS OF HYPOTHESIS TESTING                                                  10

          J. CONCLUSIONS OF THE FOURTH YEAR MONITORING PROGRAM                              10

          K. WORKS CITED                                                                    12


          APPENDIX A                 KNIK ARM WATER SAMPLING; ANCHORAGE, AK; MAY 2007


          APPENDIX B                 DATA TABLES


          APPENDIX C                 L1DAR MAPS




          Eagle River Flats NPDES Pennit Application                         page 2 of 12
          2007 - Fifth Year Monitoring Report





E-200
Draft Environmental Impact Statement for Resumption of                                                           DRAFT
Year-Round Firing Opportunities at Fort Richardson, AK




                      Eagle River Flats NPDES Permit Application
                            2007/Fifth Year Monitoring Report



A. INTRODUCTION

        BACKGROUND
        This report has been prepared in conformance with attachment F, Sampling and
Analysis Plan (SAP), of the Eagle River Flats (ERF) NPDES Permit Application. The
application was filed with USEPA Region 10 Water Permits section in April 2002 and
approved by USEPA in October 2002. The SAP outlines the collection and analysis of
water samples and the evaluation of the analytical data from those samples. The permit
application specifies that the Army will conduct a five-year sampling regime to
determine whether certain chemical constituents of military munitions are being
discharged from ERF. The purpose of the sampling regime is to perform statistical
hypothesis testing on the resultant data which, in this case, will compare the data
population of ERF offshore water samples with a background data population of Goose
Bay offshore water samples. If, at the end of the five year sampling, it is determined by
hypothesis testing that the chemical constituents tested are being discharged from ERF,
the Army will undertake to determine if, and to what extent, the elevated Shoreline
Sample values are causing adverse impacts to the environment of Knik Arm. At such
time as the determination to undertake this further study is made, USARAK will submit a
draft study plan to USEPA for review and comment.

         NECESSARY TIDAL CONDITIONS
         The SAP specifies that sampling will occur when the tidal flats of Eagle River and
Goose Bay are inundated. This condition is met only a few days per year. The 32 foot
tide datum was considered the necessary minimum tide level required to plan the
sampling events 1. Most frequently, it occurs during high spring (April/May) tides and in
late summer or early autumnal tides (August/September) in excess of approximately 32
feet above mean sea level (MSL). The areal extent of inundation of ERF as a function
of tidal elevation can be seen pictorially in Appendix C, L1DAR Maps. Appendix C
includes five maps of ERF created by L1DAR (Light Detection and Ranging) imaging.
L1DAR mapping enables the user to detect much finer elevation increments than would
be possible with photogrammetry. L1DAR images can measure elevation increments as
little as one foot. The maps show the approximate 2 extent of inundation at one-foot tide
elevation increments from 29 feet to 33 feet, inclusive. It is clear that the selection of a

I Flooding tides occur over short periods of (usually) two to four days. The maximum predicted flooding tide

elevation in this period is preferred for the sampling of the ERF.
2 The LIDAR images are approximate to the extentlhat they cannot show the moving progression of inundation as

the tidal wave flows southeast from the coastal beach toward the bluffs surrounding the ERF ... and back.


Eagle River Flats NPDES Penuit Application                                            page I ofl2
2007 - Fifth Year Monitoring Report




                                                                                                                 E-201
Draft Environmental Impact Statement for Resumption of                                                                          DRAFT
Year-Round Firing Opportunities at Fort Richardson, AK




          minimum tidal elevation of 32 feet above MSL has been validated by the LlDAR
          imaging.

                In most cases, the high spring tides are considered optimal for sample collection.
          There are essentially two reasons to support this timing:

          •	 The ERF Impact Area is currently used for artillery and mortar training only during
             the winter season when certain minimum ice depth conditions are met. Samples
             collected during the next following inundating tides (after ice conditions have abated)
             will tend to maximize the potential to detect (accumulated) contaminants from
             military munitions (if any) that may be carried off ERF Impact Area into Knik Arm;

          •	 Spring snowmelt runoff greatly increases the discharge volume of Eagle River. The
             increased freshwater discharge from Eagle River augments the volume of salt water
             tidal inundation and increases the effective level of inundation of ERF Impact Area.
             While this additional (fresh) water volume is absent during the autumnal tide cycle,
             the basic tidal inundation level is usually the determining factor.

                 SELECTION OF SAMPLING DATES
                 The selection of sampling dates is also dependent on the level of ice cover on
          the ERF. Winter training with point-detonating fuzed artillery ammunition is limited to
          those ~eriods when ice thickness on the ponds of ERF is equal to or more than five
          inches as measured at three points on the ERF Impact Area. Firing ceases (usually
          early spring) when this condition is no longer met. Ice thickness normally decreases to
          less than five inches between late March and mid-April.              Before ice thickness
          decreases, ERF is mostly covered by ice and snow up to several feet thick. Munitions
          fragments and chemical constituents impacting on the ERF will tend to be entrained and
          immobilized in the ice during recurrent freeze/thaw cycles.        Inundating tides during
          freezing conditions prior to the late March through mid-April time frame will tend to cover
          such munitions fragments and constituents with more ice rather than entrain and
          dissolve them. Hence, there is reason to delay sampling until after surface ice
          conditions have abated

                 Sampling is restricted by safety considerations. Long-term Cook Inlet and Knik
          Arm ice cover data show that, until early April, ice cover is 25% - 50%4. Crew and boat
          safety requires essentially ice~free conditions in Knik Arm 5 . These conditions (above)
          were not met until May 15 - 18, 2007 when sampling was conducted.




          3 This condition is two inches for mortar rounds.

          4 Mulherin, Nathan, William B. Tucker Ill, Orson P Smith, William J. Lee. Marine Ice Atlas for Cook Inlet. U.S.

          Army Corps of Engineers, ERDe and National Oceanographic and Atmospheric Administration, May 200 I.

          S As noted herein, there is approximately a two-hour window within which the water samples can be collected.

          Time that would be spent navigating through sea ice (even if that were not a boat safety issue) would decrease the

          time available for sampling.


          Eagle River Flats NPDES Permit Application                                                page 2 of 12
          2007 - Fifth Year Monitoring Report




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Draft Environmental Impact Statement for Resumption of                                                                 DRAFT
Year-Round Firing Opportunities at Fort Richardson, AK




B. CHANGES IMPLEMENTED IN THE 2007 SAMPLING PLAN

        Total Number of Samples
        A review of the procedures and results of the 2004 sampling event indicated that
the changes introduced in the 2004 event did improve the amount, value, and usability
of the sampling data. During the planning of the 2005, 2006, and 2007 events, it was
decided to replicate the procedures used in 2004. The evaluation made by the field
sampling personnel from the Cold Regions Research and Engineering Laboratory
(CRREL) confirmed that sufficient time was available 6 during the tidal discharge cycle to
collect all of the planned number of samples provided that wind, weather, and visibility
conditions did not adversely impact crew safety. The duration of the tidal discharge
limits the number of samples that can be collected. This duration of the sampling period
is limited in two ways.        It includes, essentially, the amount of time from the
approximately one-half hour past the peak of the high tide (when the ebbing tide is truly
running out) to the time the main surface? of the wetlands reappears. The other
limitation is the depth of water under the boat. As the tide ebbs, there is a danger of the
boat becoming grounded and stranding the crew. Boat operation in such hazardous
conditions is not acceptable. This time window, then, is approximately two hours. The
experience and efficiency gained by the sampling crew with each year's sampling
allows the maximum number of samples to be collected.

       Other considerations including weather, wind velocity and direction, prevailing ice
conditions, sea state, changing current conditions and direction, and changing
bathymetry8 could effect the allowed sampling time and 1he safety of the boat crew. In
2006, sea and weather conditions were favorable and the crew was able to complete all
planned sampling within the acceptable time frame.

         Focused Drainage Channel Sampling

        • Eagle River Flats/Eagle Bay
       As was done in the 2004, 2005, and 2006, the 2007 sampling event included
focused sampling of the five larger drainage channels and Eagle River. It was
determined in 2003 that a significant volume of the outgoing tide is discharged through
these channels. The topography of Eagle River Flats differs from that at Goose Bay in
that there is a beach head-wall that is two to three feet higher than the wetlands behind
it. The head-wall runs over approximately 2h to % of the ERF beach front. The head-
wall forms a minor barrier to tidal sheet flow off ERF. The mass and momentum of the
tidal outflow around this head-wall cuts the drainage channels. These channels have
proven to be semi-permanent and navigable for short distances for small, shallow-
draught boats ... such as the one used in the sampling.




6 Depending, of course, on optimum sea and weather conditions.

7 Numerous pemtanent and semi-pennanent ponds seldom drain completely or in a short time.

S Bathymetry can be effected by the high deposition rate of glacial till from the water column and the scouring and

re-depositional effects of high tidal current velocities.


Eagle River Flats NPDES Penn it Application                                               page 3 of 12
2007 - Fifth Year Monitoring Report




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