Title : Blasting for fill rock, McMurdo< Type : Antarctic EAM NSF Org: OD / OPP Date : June 1, 1993 File : opp93008 DIVISION OF POLAR PROGRAMS OFFICE OF SAFETY, ENVIRONMENT AND HEALTH 202/357-7766 MEMORANDUM Date: October 2, 1990 From: Environmental Officer, DPP Subject: Environmental Action Memorandum (Blasting for, and Placement of, Fill Rock at McMurdo Station, Antarctica During the 1990-1991 Season) To: File S.7 (Environment) The U.S. Antarctic Program (USAP) has developed a policy, and implementing procedures, to minimize the potential environmental and aesthetic impacts associated with gathering of local fill. The policy recognizes that the collection and use of local antarctic fill materials for use in construction and other purposes poses potential environmental and aesthetic impacts and is controversial. Nonetheless, the USAP recognizes that there is a genuine need for such material in construction and other purposes and believes that the collection and use of this natural resource can be managed with the goal of minimizing such impacts. The policy's goal is being achieved through: 1) a system for considering, authorizing and reporting all instances of fill gathering (including such activities as use of explosives to facilitate fill gathering, and grading); 2) evaluation and utilization of other materials, approaches or technologies that lead to minimization of fill gathering; and, 3) collection and maintenance of information on collection of fill and associated activities at McMurdo Station. This Environmental Action Memorandum (EAM) is intended to document how the various requirements of the policy are being met in light of needs for fill materials at McMurdo Station during the 1990-1991 season. Authorizations are now required for blasting and fill gathering activities not already addressed in a project-specific environmental impact assessment or in the U.S. Antarctic Program's Programmatic Environmental Impact Statement: These include obtaining rock fill for: o Construction of McMurdo Station's submerged domestic sewage outfall quay; o Maintenance to counter erosion of McMurdo Station's potable water intake quay; and o Finalizing grading at McMurdo Station's new Science Facility. Also, documentation is required for gathering and placement of fill for such non-project-specific activities that occur on an annual basis at McMurdo Station as: o Provision of fill for utility road crossings; and o Provision of fill for road maintenance. USAP's civilian contractor was tasked with answering the following questions to aid decisionmaking on the potential significance of environmental and aesthetic impacts associated with gathering (i.e., blasting) and placement of fill materials: Question 1: Which areas will be affected (include areas of removal or placement, and where blasting and grading will occur)? Response 1: The areas to be blasted are included in McMurdo Station's Blast Site No. 2 (shown on Map 1). Specific areas where fill will be placed include: 1) the sewage outfall quay; 2) the potable water intake quay; and the site of the new Science Facility. General areas of fill placement will be at utility road crossings and on road surfaces. Question 2: What is the nature of disturbance that the areas have experienced in the past? Response 2: The areas to be blasted have been scraped in past years for gathering of fill. The areas near the sewage outfall and water intake quays both have been disturbed by placement of rock and fines fill during construction of the quays; also, the marine environment near the outfall quay receives inputs of sewage-related nutrients and sediments (the environmental impacts of these inputs as well as of actions to mitigate the impacts were assessed previously). The area around the new Science Facility is a site of continuing construction; and, the impacts of this project have been assessed previously. Finally, fill is placed annually at utility road crossings and on road surfaces around McMurdo Station. Question 3: What indications are there that antarctic wildlife may inhabit the affected sites? Response 3: Antarctic wildlife do not normally inhabit or traverse the site of the proposed blasting which has been previously scraped; and, such wildlife are not found at terrestrial sites of fill placement. Antarctic marine biota (i.e., primarily, phyto- and zoo-plankton, benthic and pelagic organisms) are present, however, in McMurdo's nearshore waters-- and at the sites of fill placement for quay construction and maintenance. Potential impacts to these organisms was assessed in the environmental impact assessment on wastewater noted above. Question 4: What alternatives to the collection and placement of local fill have been considered? Response 4: The civilian contractor has considered importation of fill materials. Import of such materials was found to be prohibitively costly and logistically infeasible. An old rock fill quarry located at Observation Hill was noted to contain good rock; but, this area was not chosen due to potential environmental and safety risks. Blast Site No. 1 (see Map 1) contains suitable fill material; however, its proximity to fuel lines poses safety risks. Areas at Arrival Heights, near the station, were explored but suitable rock material was not found. An area near the termination of the Pram Point fuel line contained suitable rock; collection of that material would require coordination with the New Zealand Antarctic Research Program's Scott Base and would require moving collected material greater distances than from the Blast Site No. 2 area. Question 5: How much fill material would have to be collected? What will this fill material be used for specifically? Response 5: Approximately 4,000 cubic yards. That is, ~2,500 yards3 at the outfall quay and ~500 yards3 at the intake quay; ~100 yards3 to fill gabions at the outfall quay; and, ~900 yards3 for such miscellaneous, annual projects as fill for utility road crossings and road maintenance, and for final grading at the new Science Facility. Question 6: Describe the work plan for blasting operations. Response 6: Three explosive shots will be accomplished to establish a working face on the parent material. Each shot will cover an area 80' x 6' deep (~142 yards3) using 106 pounds of ICI AN95-65mm explosive, 250 feet of detcord, 9 surface delays, and one electric cap. An area will be excavated from Blast Site No. 2, back toward Blast Site No. 1. On the working face, six shots each of area 80' x 24' x 8' will be made, using 425 pounds of AN95-65mm explosive, 3,600 feet of detcord, 250 surface delays, and 6 electrical caps. Holes will be 8 feet deep with 8 foot spacing and 6 feet of burden. Upon completion of quarry operations, approximately six shots (similar to those for establishing the working face) will be required to remove the face, slope the area, and reduce future hazards to pedestrian and equipment traffic. Then the site will be graded (re-landscaped) to its original aspect to blend with the surrounding area. No waste materials will be left at the site. FINDING: There is no question that operations required for the collection (i.e., blasting of bare rock surfaces) and placement of fill will engender genuine environmental and aesthetic impacts to the chosen area; however, the blasting and collection are not new uses of that land parcel, and do not change the traditional use of the site. Blasting and removal of rock from the location does not pose a risk to any significant assemblages of antarctic wildlife. Such wildlife as rock surface-inhabiting mosses and lichens do not exist at the site. Collection of this fill material will help to continue operational and maintenance aspects of the U.S. Antarctic Program without posing a significant or undue impact to the antarctic environment. The policy and procedures now established for the consideration, justification and documentation of fill gathering activities will help USAP to minimize the need for, and potential impacts of, these activities. The Operations Research Analyst, DPP, shall compile pertinent information on this activity in a "local fill collection database" to inform future authorizations and decisionmaking as instructed by Safety, Environment and Health Program Policy Memorandum 90-2 (October 1, 1990). Approval is granted for collection of fill materials, according to the plans outlined by the civilian contractor (and as digested in this Environmental Action Memorandum). Sidney Draggan cc: Safety, Environment and Health Officer, DPP Acting Manager, Polar Operations Section, DPP Facilities Engineering Projects Manager, DPP Head, Safety, Environment and Health Implementation Team, DPP Environmental Engineer, DPP Operations Research Analyst, DPP