NAVAL AIR STATION CORPUS CHRISTI

SWMU 1, the Defense Property Disposal Office (DPDO) landfill reportedly operated between 1949 and the early 1960s. It is now an approximately 13 acre, grass-covered field located 400 feet west northwest of the CCAD landfill. The average elevation at SWMU 1 is 18 to 20 feet MSL, but the topography is characterized by approximately linear ridges generally oriented in a northeast to southwest direction. The surface soil is silty fine sand, which is frequently mounded by gopher activity. A drainage ditch, which originates on the installation golf course, defines the northwest and west boundaries of the site. SWMU 1 is further bound on the northeast by First Street, on the east and southeast by the asphalt-paved DRMO yard and on the southwest by a portion of Perimeter Road.

The DPDO landfill was reportedly used for disposal of bulk chemical waste generated by CCAD overhaul operations (helicopter maintenance). Four or five seepage pits were used for direct disposal of liquid waste. These waste materials included organic solvents, sulfuric and hydrochloric acids, paint remover and thinner, and plating waste. Estimated quantities of disposal range from 2,000 to 5,000 gallons per week. DPDO- and CCAD-generated waste was disposed of in open, shallow trenches. Exposed debris included wood, rubber, some asphalt, brick fragments, tile, broken shingles, glass, and melted aluminum. General solid waste generated by CCAD, NAS Corpus Christi, and NAS Corpus Christi housing was also disposed of in the area.

SWMU 2, the CCAD landfill, was reportedly active between 1960 and 1972, and was the primary disposal area for bulk chemical waste generated at the CCAD. SWMU 3, encompassing approximately 15 acres, is a slightly mounded field ranging in elevation from approximately 23 feet MSL in the central area, to approximately 16 feet MSL along the boundary. The site is bound on the northeast by First Street, on the southeast by a gasoline station and a former commissary, with Lexington Boulevard further to the southeast. The DRMO Yard and its frontage road form the northwest boundary, and the southwest boundary is generally marked by a gravel road, IR Site 4, and an underground water storage tank. Approximately linear ridges with relief ranging from 1 to 3 feet cover the site.

As presented in the 1984 Initial Assessment Study, aerial photographs from 1967 show several pits (approximately 50 feet in diameter) in the area. These pits were reportedly used as seepage pits for chemicals collected in bowsers at CCAD. Between 2,000 and 5,000 gallons per week of organic solvents, sulfuric and hydrochloric acids, paint remover and thinner, and plating waste were disposed of at the site. The area was also used for the disposal of general solid waste such as shingles, cans, concrete pipe, reinforcement rods, sheet metal, and scrap lumber.

SWMU 4, the Firefighting Training Area (FFTA) was operated from the 1960s until 1991. This site is adjacent to the southern portion of the CCAD landfill (SWMU 2), over a former nonhazardous waste landfill. SWMU 4 is presently described as a circular area of approximately 17,000 square feet, with a relatively bare, sandy gravel surface. The site was used for training five to six months each year. The training activities used approximately 3,000 gallons per month of waste fuel. The waste fuel, a mixture of jet fuel (JP-4) and aviation gasoline (AVGAS), was discharged to the ground and ignited for practice in extinguishing the blaze. Reportedly, in 1973 a clay liner and berm were added to the previously unlined area.

The Affected Property Assessment Report (APAR) for these three SWMUs identified four protective concentration level exceedance (PCLE) zones. These PCLE zones are the result of liquid waste disposal activities in the 1960's and 1970's. The liquid waste was primarily composed of plating and solvent waste with some waste fuel. Three of the PCLE zones result from potential discharge to surface water of chlorobenzene at concentrations greater than the ecological benchmark for chlorobenzene in surface water. One PCLE zone for groundwater ingestion of cis-1,2-dichloroethene is co-located with one of the chlorobenzene PCLE zones. Two PCLE zones for groundwater ingestion of vinyl chloride have been identified, one of which is co-located with the cis-1,2-dichloroethene PCLE zone and one independently located as the fourth PCLE zone.

The Response Action Plan (RAP) for these three SWMUs identifies the remedial actions that have been implemented in order to control and reduce contamination in the four PCLE zones. A French drain has been installed to intercept the flow of groundwater, contaminated with chlorobenzene to the surface water ditches at the northern boundary of SWMU 1. For the remainder of the site Monitored Natural Attenuation (MNA) is used to reduce the concentrations of contaminates at the site.

The term "Building 8", describes a block of approximately 40 acres, bound by Ocean Drive on the north, 4th Street on the east, Avenue D on the south and Crecy Street on the west. The actual building occupies approximately 20 acres of the site, and other associated buildings occupy approximately 5 additional acres of the site. With the exception of strips of grass along the northern half of the Cercy Street boundary and on the south side of Ocean Drive, the site is paved with concrete or asphalt. The total un-paved area is approximately one half acre.

Building 8 is leased by the CCAD, which serves under the United States Army Material Development and Readiness Command. CCAD's primary operations include performing depot-level maintenance of Army aircraft and aeronautical equipment, training military personnel in depot-level maintenance, and preparing aircraft for overseas shipment. Various industrial actives are conducted within the Building 8 complex, including parts cleaning and degreasing, bulk fuel storage, and painting.

Groundwater samples have been collected from 30 monitoring wells and three cone penetrometer test points in the shallow aquifer at Building 8. One groundwater PCLE zone was identified in the Affected Property Assessment Report. Trichloroethene was detected above the critical PCL north of Building 8. No soil PCLE zones were identified during the affected property assessment. Due to the sensitive nature of operations within Building 8, sampling through the floor of the building was not conducted; therefore the entire soil column beneath the footprint of Building 8 was declared a soil PCLE zone.

Exposure to contaminants of concern in groundwater and soil will be prevented by institutional controls and an engineered cap. Institutional controls will be implemented to limit land use to an industrial classification and prohibit use of shallow groundwater. The engineered cap is the in-place concrete floor of Building 8. The shallow aquifer meets Class 3 criteria and is not presently used for any purpose. Contaminants of concern will remain in the shallow groundwater while natural attenuation permanently decreases their concentrations. Groundwater data collected from the lower confined aquifer has confirmed that contaminants of concern are not migrating beneath the clay at the base of the shallow aquifer.

SWMU 9, the North Gate Disposal Area, is located approximately 1,600 feet west of the North Gate and 600 feet south of the Patrol Road. Reportedly pits were dug in this area during the late 1960’s and 1970’s for disposal of liquid wastes generated at Corpus Christi Army Depot (CCAD). Disposal of liquid at the site was reportedly not on a consistent basis.

During the winter of 2005 groundwater samples were collected, in support of a Site Investigation (SI). One volatile organic compound was detected at a concentration less than the Texas Risk Reduction Program (TRRP) Tier 1 Residential Protective Concentration Level (PCL) and four metals were detected at concentrations less than their TRRP Tier 1 Residential PCLs. Based upon these results the site was recommended for no further action.

The former Skeet Range is located in the southeastern corner of the installation, 1230 feet southeast of Runway 31 and 400 feet north of Oso Creek. A former drainage ditch lies to the west of the former range, while another drainage canal currently intersects the eastern end of the former range area. The area surrounding the former range is open and covered in vegetation.

The former Skeet Range was originally constructed in 1942 through 1943. Initially, the site contained one skeet range firing area composed of two large firing arcs for skeet shooting, three smaller firing arcs for trap shooting, and an armory. Wood-frame “high” and “low” skeet houses were positioned at the end of each skeet firing arc, which measured approximately 148 feet in length. The trap firing arcs present on the east side of the range were smaller in size than the skeet firing arcs (approximately 82 feet in length), and had trap houses centered in the middle of each firing arc. By January 1944, an additional skeet firing arc was added on the western side of the skeet range. All firing arcs faced to the southwest toward the installation boundary and Oso Creek. WWII-era skeet and trap ranges were typically constructed with five firing positions per firing arc.

Station records and aerial photographs indicate the skeet range was expanded in 1943 through the addition of the pistol range to the west. The two ranges were connected by a road and sidewalk. The pistol range was located 200 feet west of the skeet range and consisted of 15 firing positions facing to the southwest towards an earthen target butt positioned 50 yards from the end of the firing area. Pistol ranges were typically constructed with firing lines located 10 feet, 25 feet, and 50 feet from the target area.

The Skeet Range was generally used for small arms qualification and moving target orientation training for naval aviators, although the ranges may have also been used for recreational purposes. Ammunition used at the site likely included: 12-, 16-, and 20-gage and .410 caliber shotgun munitions; and other small caliber ammunition [e.g., .22 caliber, .38 caliber, .45 caliber, 9-millimeter (mm)] which were likely used at the range for pistol training purposes. The armory associated with the former Skeet Range is no longer present at the installation, and the date of decommissioning is not known. The former small arms magazine remains in place in an open field east of a drainage canal on property no longer owned by the installation. The Skeet range was demolished between 1958 and 1964.

Five polyaromatic hydrocarbons (PAHs) [benzo(a)anthracene; benzo(a)pyrene; benzo(b)flouranthene; dibenzo(a,h)anthacene; and indeno(1,2,3-cd)pyrene] and one metal (lead) were detected in the shallow surface soils (0 to 1 foot below ground surface) at concentrations greater than the PCL during the Site Investigation and Remedial Investigation.

The former Skeet Range at ALF Waldron is an approximately 8.6-acre area located in the northeastern portion of the installation, 520 feet northeast of the intersection of Runway 31 (still active) and Runway 26 (abandoned but still visible). The range area is bounded on the south and west by Runway 31, and by grasses, shrubs, trees, and the installation fence line to the east and north. Station drawings indicate the Skeet Range was constructed in March 1945 and was used for cadet and security personnel weaponry training and qualification, moving target orientation training of naval aviators, and potentially recreation.

The range was composed of three skeet firing arcs facing to the north, situated end-to-end. Each firing arc contained a “high” skeet house on the west side of the arc, and a “low” skeet house on the east side. The range also contained a gunnery building, east of the skeet arcs that may have housed ammunition for use at the Skeet Range. Ammunition used at the site likely included 12-, 16-, and 20-gauge and 0.410 caliber shotgun ammunition and possibly other small arms ammunition. Station drawings indicate the range was demolished sometime between June 1947 and July 1961. No records were found indicating the methods or the exact date of the range demolition; however, the installation Point-of-Contact indicated that the range was most likely brought to grade by bulldozing. The area where the Skeet Range was located is currently overgrown with vegetation, and there is no visual evidence of the former structures associated with the range (e.g., no ground scarring or concrete). Future use is not expected to change.

During the Site Investigation five PAHs (benzo(a)pyrene, benzo(a)anthracene, benzo(b)fluoranthene, dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene) were detected at concentrations greater than the TRRP Tier 1 Residential PCLs. Lead was also detected at concentrations greater than the TRRP Tier 1 Residential PCL.

The Gunnery Department Training Complex, constructed in July 1941, was located in the southwest corner of the installation, south of the installation runways. The complex contained six small arms ranges, three large earthen target berms, an armory, an instruction building and carpentry shop, and a paint and oil shed. The complex was used to train naval aviation cadets through a two-week concentrated course in aviation gunnery on the ground, as well as to provide small arms training and qualification for installation officers, enlisted men, and security forces.

The six small arms training ranges are described below.

Small Arms Range

The Small Arms Range was an approximately 2.9-acre range located on the western side of the Gunnery Department Training Complex and was used for small caliber handgun training and qualification. The range was comprised of a Pistol House, an earthen target berm, target stands, wooden plank sidewalks, and firing lines positioned 25 and 50 yards from the target stands. The range was constructed in 1941, closed in 1975 due to encroachment of local development, and demolished in 1982. The target berm was leveled across the range floor. The area is currently covered in vegetation and is not used for military purposes. Future use is not expected to change.

There is no historical or physical evidence of MEC at the Small Arms Range. Based on historical use and the duration of operations at the site, it is possible for MC, including lead, other metals, and black powder constituents, to be present in surface soils at the Small Arms Range and, possibly, the surface water and sediments of Oso Bay to the west.  During the Site Investigation nitroglycerin was detected at concentrations greater than the TRRP Tier 1 Soil to Groundwater PCL.

Fixed Target Range

The Fixed Target Range was an approximately 1.8-acre range located on the south side of the Gunnery Department Training Complex and was used for machine gun training of naval aviators.  The range was comprised of a covered shelter, eight tripod-mounted machine gun platforms, and a series of fixed targets placed in front of an earthen target berm. Browning .30 caliber machine guns mounted on the platforms were oriented for firing towards the fixed targets in a southwesterly direction. The range and target berm were constructed in 1941 and demolished sometime after 1970. The area is currently covered in vegetation and is not used for military purposes. Future use is not expected to change.

There is no historical or physical evidence of MEC at the Fixed Target Range. Based on historical use and the duration of operations at the site, it is possible for MC, including lead, other metals, and black powder constituents, to be present in surface soils at the Fixed Target Range.  During the Site Investigation two metals (lead and antimony) were detected at concentrations greater than the residential PCL.

Air Blast and Synchronized Gun (AB/SYN) Range

The AB/SYN Range was constructed in 1941 and occupied approximately 2.5 acres on the northern side of the Gunnery Department Training Complex. The range included an Air Blast House, target areas, an  earthen target berm and, possibly, mounted machine gun positions. The range appeared to be divided into an air blast range and a synchronized gun range, although exact types of training performed at the range are unknown. It is likely that Naval aviators were taught boresighting procedures at the synchronized gun portion of the range. If so, munitions used at the range may have included .30 caliber small arms. Munitions used at the air blast portion of the range are unknown. Military operations at the range ceased at an unknown date, and the entire range was demolished by 1970. The installation of a TACHAN aviation tower directly north of the range may have led to the demolition of the AB/SYN Range. The area is currently covered in vegetation and is not used for military purposes. Future use is not expected to change.

There is no physical evidence of MEC at the AB/SYN Range. Based on possible historical operations at the site, it is possible for MC, including lead, other metals, and black powder constituents, to be present in surface soils at the AB/SYN Range.  During the Site Investigation lead and benzo(a) pyrene were detected at concentrations greater than the residential PCL.

North Trap Range

The North Trap Range occupied approximately 8.5 acres on the northwest side of the Gunnery Department Training Complex and was utilized by Naval aviation cadets for moving target orientation training. The range was comprised of four wooden plank trap arcs facing to the northeast, with a trap house centered in front of each arc, and a clay target storage house behind the firing arcs. Munitions use was limited to small arms, primarily shotguns (12-, 16-, and 20-gage and .410 caliber ammunition). The range was constructed in 1941 and demolished sometime after May 1959. The area is currently covered in vegetation with no military use.  Future use is not expected to change.

There is no historical or physical evidence of MEC at the North Trap Range. Based on historical use and the duration of operations at the site, it is possible for MC, including lead, polycyclic aromatic hydrocarbons (PAHs), other metals, and black powder constituents, to be present in surface soils at the North Trap Range and, possibly, the surface water and sediments of Oso Bay to the west.  During the Site Investigation four (benzo(a)pyrene, benzo(b)fluoranthene, dibenzo(a,h)anthracene and Indeno(1,2,3-cd)pyrene) PAHs and lead were detected at concentrations greater than the residential PCL.

South Trap Range

The South Trap Range occupied approximately seven acres on the southwest side of the Gunnery Department Training Complex and was utilized by naval aviation cadets for moving target orientation training. The range was comprised of four trap arcs facing to the southwest, with a trap house and skeet house centered in front of each arc. A platform with a swivel-mounted shotgun with scope was placed on the firing arc facing to the southwest. A portion of the firing fan of the range extended over Oso Bay. Munitions use was limited to small arms, primarily shotguns (12-, 16-, and 20-gage and .410 caliber ammunition). The range was constructed in 1941 and demolished sometime after May 1959. The area is currently covered in vegetation with no military use. Future use is not expected to change.

There is no historical or physical evidence of MEC at the South Trap Range. Based on historical use and the duration of operations at the site, it is possible for MC, including lead, PAHs, other metals, and black powder constituents, to be present in surface soils at the South Trap Range and the surface water and sediments of Oso Bay to the southwest.  During the Site Investigation five (benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenzo(a,h)anthracene and Indeno(1,2,3-cd)pyrene) PAHs, arsenic, copper, and lead were detected at concentrations greater than the residential PCL.

Skeet Range

The Skeet Range was constructed in 1941 and occupied approximately 17 acres on the eastern side of the Gunnery Department Training Complex. Naval aviation cadets utilized it for moving target orientation training. The range was composed of five skeet firing arcs facing to the northeast, situated end-to-end. Each firing arc contained a “high” skeet house on the left side of the arc, a “low” skeet house on the right side, and a trap house centered in front of each arc.  Wooden fences, approximately 15 feet in height, separated each firing arc. The range also contained clay target storage houses and observation shelters. Munitions use was limited to small arms, primarily shotguns (12-, 16-, and 20-gage and .410 caliber ammunition). The range was expanded to the north in 1973 (two skeet arcs and a trap arc) and again to the east in 1982 (three skeet arcs), with the older range abandoned after each move. The current range remains operational; therefore, only the portions of the older ranges (approximately 5.7 acres) that do not overlap with the operational range are assessed in this document. The area assessed is currently covered in vegetation and is not used for military purposes.  Future use is not expected to change.

There is no historical or physical evidence of MEC at the Skeet Range. Based on historical use and duration of operations at the site, it is possible for MC, including lead, PAHs, other metals, and black powder constituents, to be present in surface soils at the Skeet Range.  During the Site Investigation five (benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, dibenzo(a,h)anthracene and Indeno(1,2,3-cd)pyrene) PAHs, arsenic, copper, and lead were detected at concentrations greater than the residential PCL.

The Incinerator Disposal Site was located in the southern portion of the installation, 750 feet southwest of the eastern end of Runway 31 and bounded to the south by Oso Creek. Perimeter Road runs along the western and northern boundary of the site. The site is covered in dense vegetation, with open sections of wetlands on the south end near Oso Creek. Although its exact dimensions are unknown, the site may have occupied 17 acres. The site was a former sanitary landfill that also contained a boiler used to incinerate confiscated drug material, small arms, and ordnance items.

The incinerator was used incinerate small arms and ordnance items. The ultimate disposition of the ash and debris generated from the burning operations is not known. The Army had used an 8-foot long by 5-foot diameter boiler for the incineration of “small ordnance items,” including .30 and .50 caliber small arms, flares, explosive cartridges from ejection seats, and “possibly 80 mm rockets” (likely 2.75-inch rockets) at a 6-acre sanitary landfill facility. Additionally, the City of Corpus Christi also burned confiscated drug material in the boiler. Operation of the incinerator ceased before 1980.

During the Remedial Investigation four metals (antimony, cadmium, copper, and lead) were detected at concentrations greater than the TRRP Tier 1 Residential PCL. Additionally, an UXO detector-aided surface survey and munitions and explosives of concern geophysical survey was performed along twenty-four transects. Numerous surface munitions and explosives of concern were discovered at the site.