Oil Contamination is Pervasive

posted in: December 1991 | 0

The Navy has surveyed a number of sites in the Pearl Harbor area where fuel leaks, dumps, and spills are suspected of having contaminated soil or water. In some areas, oil contamination is so widespread, and the number of possible sources so vast, that it is unlikely if the cause or causes of the contamination could ever be traced with certainty.

The manifestations of oil pollution are many. Surely the best known is the sheen on the water near the Arizona Memorial, caused by the slow, steady leak of fuel oil from the battleships sunk in the Japanese attack December 7, 1941.

Less famous are the oil seeps that curtail activities at Millican Field after heavy rains, or the near-constant flows of oil into the harbor from the quay wall near Hotel Pier Wharf, or the sightings of oil in utility and sewer manholes. The strangest manifestations may be the oil wells that the Navy installs from time to time in an attempt to recover still-useful oil from underground pockets of spilled fuel.

A comprehensive listing of oil-contaminated sites known to the Navy is not possible here. What follows is a brief description of several sites, intended to give readers an idea of the scope of the oil-pollution problems related to the military’s presence at Pearl Harbor.

The Abandoned Tank

Buried under the grass-covered field that lies between the enlisted men’s dining hall and their living quarters, in an area mauka of North Road on the eastern side of Pearl Harbor, is a mammoth collapsed underground tank. The tank appears to have been constructed of concrete slabs. Its capacity is given variously in Navy documents as anywhere from 3 million gallons to 9 million gallons. However, its dimensions — 320 feet long, 125 feet wide, and 30 feet deep — would tend to suggest the tank held somewhere around 9 million gallons.

The tank was built in the early 1940s. Until 1977, it was used to store slop oil and waste Navy Special Fuel Oil. According to one Navy report, the tank held 126,000 gallons of semi-solid waste oil at the time it was abandoned. Another report, prepared by a contractor who surveyed the site recently, says 126,000 barrels of waste oil (5.3 million gallons) were in the tank at the time of its abandonment.

In any event, there is no dispute over what happened when the tank was abandoned. A demolition contractor was hired to cave in the roof and collapse the top ten feet of the tank walls. To drain the tank, he was told to drill holes in the tank floor and what remained of its walls. Following that, the site was filled to grade.

Striking Oil

Harding Lawson Associates was hired by the Navy to conduct more detailed studies of this site. The task was more difficult than anticipated. As described in a remedial investigation/feasibility study (RI/FS) work plan, prepared by another contractor, ERCE, last summer, Harding Lawson drilled eight borings and installed four water monitoring wells: “Ground water samples were collected from two wells. Wells W-3 and W-4 were not sampled due to the presence of floating free-phase product. [Harding Lawson’s] report stated that the thickness of the floating product in the wells could not be measured … due to the viscous nature of the product… Black, oily petroleum product and/or sludge was encountered during drilling of borings B-3 and B-4, and monitor well W-1.” Contaminants found include benzene, toluene, arsenic, barium, selenium, and silver.

Red Hill

In 1938, the Navy began building a fuel depot at Red Hill, which lies between Moanalua and Halawa valleys. Twenty massive underground tanks — each having a capacity of 12.6 million gallons — were built into the hill and were used primarily to store Navy Special Fuel Oil, jet fuel, aviation gasoline, and diesel fuel.

Starting in 1943, sludges and waste oil from the cleaning of these tanks were piped to an unlined waste pit 800 feet north of Moanalua Highway. A Navy history of the site describes the practices there as follows:

“Oily waste residues were pumped from the Red Hill underground fuel tanks to the site via an … ‘underground slop line’… From this underground slop line, the wastes could either be routed into the old pit or into a bypass-type piping arrangement which led towards South Halawa Stream… When wastes were routed to the old pit, recoverable oil was skimmed off the fluid surface and collected in the two aboveground 8,000-gallon storage tanks located to the northeast of the old pit. Fluid could be drained from the old pit via the ‘look box’ into the bypass piping which led to South Halawa Stream.” Between 1943 and 1945, approximately 1.3 million gallons of fuel spilled at the Red Hill fuel depot, the result of improper valve operation. The oil flowed downhill through the access tunnel, exiting near the waste pit, where it ran across the ground and into South Halawa Stream.

Up in Flames

In 1948, the Board of Water Supply’s Halawa tunnel was contaminated with diesel fuel and the pumping station was shut down from February 19 to April 27 of that year. Although an investigation showed the contamination to be unrelated to the waste pit operations, the Navy evidently decided the waste pit needed to be cleaned up anyway. In March 1948, an attempt was made to get rid of the heavy residues by burning them off. Old tires and wood scrap were thrown into the pit, diesel fuel was added, and the fire was set. After that, the Navy excavated the pit “beyond the depths of oil penetration” and abandoned the pit “to preclude any possibility of contamination of water supply from this source.”

According to a Navy report, “During the period of time between 1948 and 1972, it is believed that a portion of the waste sludges were trucked to a storage facility in Pearl Harbor, with the remainder being diverted directly to South Halawa Stream.”

In 1972, the Navy dug a new waste pit on the same site, lining it this time with asphalt. Quoting again from the Navy history of the site: “The piping system for the former disposal pit apparently was not removed during construction of the new pit and it is believed that the practice of diverting water from the pit and/or directly into South Halawa [Stream] continued until the pit was take out of service in 1987.”

Unauthorized Dumping

Concern for contaminants in this area extends beyond the area of the pit itself. About 200 feet west of the pit is a site referred to as the “discharge-disposal area,” which shows up on old aerial photographs as an unvegetated, circular white spot. According to a work plan prepared by ERCE in November 1989, “the exact nature of this white area is difficult to assess,” but “two explanations are possible. One … is that it represents waste materials that were dumped by vehicles. A second explanation is that it represents discharge from the site bypass waste line, which led to South Halawa Stream.”

Soon after the new pit was put into use, its asphalt lining began to crack. The pit was drained, and its contents were placed into 55-gallon drums. “These drums were taken a short distance away from the pit,” the ERCE report notes, “and then were emptied out upon the surface soils. The pit was then reconstructed using a concrete lining.” The ERCE report goes on to say that according to one person who used to work there, “on at least one occasion following the reconstruction of the new pit, improper valve operation … resulted in a significant amount of sludge and water being discharged directly to South Halawa Stream.”

More recently, in the early 1980s, “a subcontractor responsible for hauling wastes from the pit site to a Pearl Harbor recycling facility was discovered dumping waste material via a hose into a heavily vegetated area located about 100 to 150 feet southwest of the new pit. The possible existence of sludge pumping to this location was also documented previously.”

A Threat to Aquifer

The site lies above the Pearl Harbor aquifer, the most important source of drinking water for O`ahu. In between the pit and the Pearl Harbor aquifer is a so-called “perched” body of fresh water, which is separated from the lower aquifer by a layer of volcanic ash and cinders. According to a study prepared by Aqua Terra Technologies, Inc., in March 1988, “contamination from the soil is migrating vertically and has reached a depth of at least 30 feet where perched groundwater was encountered. Because surface and rainwater recharge the basalt drinking water aquifer through a permeable lens of weathered basalt, the potential exists for petroleum hydrocarbon compounds to migrate from the soil into deeper formations, eventually encountering the drinking water aquifer.”

The Navy’s plans for further site investigation call for drilling test bores into the soil to assess the level of contamination. When the Department of Health learned of this, it immediately voiced concerns to the Navy that the test bores could easily reach into the lower aquifer and could “act as conduits between contaminants and the deep aquifer.”

The Navy appears to have been worried that news coverage of the Red Hill site might pose a public-relations problem for it. To head this off, the Navy retained Hill & Knowlton/Communications-Pacific, Inc., to develop a “community relations plan.” That plan, prepared in November 1989, discussed past media coverage of four “cases involving toxic wastes,” including the Pearl City Peninsula landfill. (It noted that “EPA studies have downgraded the toxicity” of that site, although in fact, ongoing EPA studies led to its inclusion in the National Priorities List recommendation of this year.) Moreover, notwithstanding the concerns for water contamination raised by the Aqua Terra Technology study of 1988, Hill & Knowlton/Communications-Pacific stated that the City and County of Honolulu’s pumping station was separated from the waste pit “by relatively impermeable rock that might prevent” the migration of contaminants.

Navy operations are not solely responsible for fuel leaks into Halawa Stream. For eight months in 1988, an underground tank at the state’s Halawa prison leaked diesel fuel into the stream. A nearby resident notified the state of the leak in February, but it was not until September that the state made any effort to stop the leak or clean up the spill.

Ewa Junction

On March 12, 1971, vandals activated a fuel pump on one of two underground storage tanks at the Navy’s fuel drumming facility in Ewa Junction. By the time the spill was discovered (not until the next day), about 315,000 gallons of automotive gasoline, or MOGAS, in Navy terminology, had flowed onto the surrounding land, forming a pool one to two feet deep and 150 feet in diameter.

The Ewa Junction facility, no longer in use, occupies land between Leeward Community College, to the east, and the athletic field of Waipahu High School to the west. Watercress farms lie to the south.

The City and County of Honolulu intends to give the Navy its land on the Pearl City Peninsula, site of an abandoned sewage treatment plant, in return for the Navy turning over this site to the city, for use as a maintenance facility and station for the proposed rapid transit system. A draft memorandum of understanding acknowledges the Navy’s monitoring and cleanup program, but provides also that should the city desire further investigation or cleanup of the site, costs will be shared equally by the Navy and the city. (The trade is not an even swap; because the Navy’s land at Ewa Junction is presumed to have a higher market value, the city will be paying the Navy the difference between the fair market value of the Ewa Junction site and that of the old sewage treatment plant site.)

In response to the 1971 spill, the Navy recovered 32,000 gallons by pumping out the gasoline “lake.” The remainder seeped into the soil, coming to rest on top of the groundwater table. A T-shaped “interceptor trench,” 19 feet at its widest point and 27 feet at its deepest, was dug on the southern boundary of the site, intended to protect groundwater supplies used to irrigate the watercress farms. (Water, with the fuel floating on top, accumulated in the trench, allowing the Navy to skim off the oily portion.) In addition, 57,000 gallons were pumped from six oil wells drilled in the vicinity. The initial pumping, the trench, and the wells recovered altogether fewer than 100,000 gallons — less than a third — of the 315,000 gallons released.

Additional Contaminants

The 1971 release is not the only potential source of contamination at this site. As noted in a site inspection report prepared by Harding Lawson Associates in August 1990, the drumming facility is downslope of areas in Central O`ahu where contamination of groundwater by ethylene dibromide (EDB), trichloropropane (TCP) and dibromochloropropane (DBCP). EDB and DBCP were used as soil fumigants, while TCP is an impurity in another fumigant, dichloropropane-dichloropropene, or DD.

The agricultural application of EDB and DBCP has been prohibited since 1983 and 1977, respectively. However, EDB and TCP have non-agricultural sources as well, which may have contributed to the contamination of Central O`ahu wells. As the Harding Lawson report states, “EDB is an additive in leaded aviation fuels, and TCP is a solvent and degreasing agent and is a component of paints and varnish removers. Several leaks of aviation fuels (AVGAS and JP-4) have been documented along the route of the Air Force’s POL (Petroleum, Oil and Lubricants) fuel storage and transmission pipeline… Four AVGAS leaks in the 1950s, one reportedly as high as 300,000 gallons, occurred upgradient and within one mile of the Ewa Junction” site.

Preliminary soil testing shows high levels of some contaminants. Benzene, for example, is present at levels as high as 1.3 parts per million, roughly a thousand times the cleanup standards set by the state Department of Health. Concentrations of lead are an order of magnitude greater than permitted by DOH. Water samples show the presence of lead, ethylbenzene, and benzene at levels far exceeding state cleanup goals. Consider benzene again: the state cleanup goal is 3 micrograms per liter (or parts per billion). Near one tank, groundwater samples show a concentration of benzene approaching a thousand times that, or 2,900 micrograms per liter.

At one monitoring well, Harding Lawson Associates found “floating product,” yellowish to clear in color, and having a hydrocarbon odor. The thickness ranged from one-tenth to two-tenths of a foot. Water recovered from two other monitoring wells — there were four such wells altogether — had a surface sheen of oil.

The Harding Lawson study concluded that “some of the aromatic hydrocarbon contaminants such as benzene … have dissolved into the groundwater in appreciable concentrations (up to 2900 mg/l). … The residual gasoline appears to be slowly contributing soluble components of [benzene] and lead to the groundwater.” While acknowledging that DOH cleanup standards for petroleum-contaminated soil and groundwater are exceeded at the site, the study adds that “these goals were established with the objective of protecting human health and the environment… However, if it can be shown that human health or the environment are not threatened … other cleanup goals might be acceptable.”

Another site study was conducted for the Navy by Environmental Science and Engineering, Inc. Aside from confirming Harding Lawson’s findings of hydrocarbon contamination, it detected heptaclor in soil near one of the two underground storage tanks.

The POL Pipeline

Starting in 1940, the Department of Defense has operated a Petroleum-Oil-Lubricant (POL) pipeline from Hickam Air Force Base, which lies between Pearl Harbor and the Honolulu Airport, to near Wheeler Air Force Base, in central O`ahu. At the present, the pipeline system includes 28 miles of ten-inch pipe and three fuel storage areas, having a combined capacity of 32 million gallons. In the past, storage areas were located also in what is now Mililani Town.

In 1987, the Air Force undertook an investigation to try to pinpoint sites where fuels from the pipeline may have escaped into the surrounding areas, either through leaks, ruptures, spills, or deliberate discharges. Before the study, the Air Force had been aware of 19 contaminated sites in the pipeline system. This study identified 61 more sites, for a total of 80.

Tanks in Mililani?

Besides the newly discovered contamination, the Air Force in 1987 located six sites of potential contamination that it had forgotten about. These were areas where fuel storage and handling had occurred in the past, but which had been abandoned years ago. They include four fuel storage tanks and a former drumming plant near Wheeler, and eight abandoned storage tanks in four different residential areas of what is now Mililani Town: at the intersection of Apele Street and Apele Place, in the vicinity of Meheula Avenue and Hokuahiahi Street; near Hokupalemo Street; and near Holaniku Place.

The Air Force did not study these areas of potential contamination, nor did it look into possible contamination at the 12 active fuel storage tanks (of 13 total) where no leaks or spills had been reported in the past. That is not to say that these are clean sites, however. As the Air Force stated in its report, “Given the fact that these tanks have been in place for more than 40 years, it is reasonable to assume that they also may represent potential contamination sites. It is not clear that fuel inventory and fuel transfer measurements are precise enough to indicate the presence of all leaks or to ascertain the volume of fuel lost if a leak should occur. Therefore, there exists the possibility that undetected leaks have occurred or are occurring from storage tanks and/or the transmission pipelines.”

To be sure, inclusion on the list of 80 identified sites does not necessarily mean that a given site remains contaminated to the present. Contamination at some sites dates back to the 1940s, nearly half a century ago.

Migrating to the Water

But the potential threat of groundwater contamination does not always recede with the passage of time. Indeed, after the lighter parts of oil have evaporated, the heavier portions can continue to work their way down into the soil. The longer the passage of time, the deeper the oil can sink. Almost the entire pipeline system lies above the Pearl Harbor aquifer.

Several major Board of Water Supply wells are in the area of the POL pipeline and associated fuel storage areas. As the Air Force report notes, several of these wells “have been found to contain organic compounds, including those used for agricultural purposes, industrial and commercial purposes, and compounds contained in fuels and other petroleum products.”

“Findings from the water sampling phase of this investigation reveal no conclusive evidence of fuel contamination at the 10 wells sampled,” the report says. However, it adds:

“A review of existing water-quality data indicates three water sources in the Pearl Harbor aquifer where fuel contamination may have occurred. … The basis for this suspicion is the reported presence in water from these wells of the aromatic hydrocarbons benzene, and ethylbenzene, and possibly toluene and xylene. These compounds are common fuel hydrocarbons.”

Volume 2, Number 6 December 1991

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