Pollution Is New Enemy for Marines : Flow of Sewage Raises Effluent

When the Camp Pendleton Marine Corps Base was built nearly half a century ago, the military faced a problem as daunting as a beach landing in enemy territory: how to provide water for thousands of Leathernecks in a land where the rivers sometimes run dry.

No one is quite sure who came up with the notion, but since those early days, the base has subsisted entirely on water tapped from vast underground aquifers, which are recharged by allowing treated sewage to percolate into the earth.

The system has worked remarkably well through the years--until now.

Late last month, the Regional Water Quality Control Board slapped the base with 10 cease-and-desist orders for violating state limits on the effluent it pumps into huge holding ponds on the sprawling, 196-square-mile base.

No Imminent Risk

Though there is no imminent health risk, water officials with the board are concerned that the problem, if unchecked, could taint the ground-water system that has served the Marine Corps base so faithfully for so long.

“No serious existing pollution problem has been created,” said David Barker, a senior engineer with the state board. “But, by not meeting the standards over time, it could create just such a pollution problem, which could render the ground water unsuitable for drinking purposes.”

Corps officials are well aware of the problem and eager to see it rectified. A study by a private consulting firm, expected to be completed by April, will recommend changes to get things squared away at the 10 sewage-treatment plants on base.

“We’re working together with the regional board to solve the problem,” said Lt. Col. Tony Pack, deputy assistant chief for base facilities. “Our sewage plants are old and have been there since the base began. We’ve done a lot of work with them, but they still need some improvements.”

Tests of the treated sewage produced on base have shown higher-than-normal concentrations of elements such as nitrogen and phosphorous, Barker said. Also, the total load of salts and other minerals in the water is deemed too high.

Authorities point to the sewage plants as the culprit.

Like any civilian operation, the plants use massive mechanical rakes to sift off large material, then divert the sewage into settling tanks to remove the heavy sludge that settles to the bottom.

Organisms Eat Impurities

The sewage then flows into a cylindrical bed of gravel. As the waste water trickles down through the porous material, microorganisms growing on the rock gobble up impurities. The effluent is further purified with chlorine and dumped into large, flat holding ponds.

At that point, Mother Nature takes over. Some of the effluent evaporates, but much of it percolates into the ground, the fine alluvial soil providing more cleansing. It takes anywhere from 5 to 25 years for the effluent to reach the ground-water table.

Nearly all of the holding ponds are on the western edges of the base, downstream from the 36 wells used to pump water from the eastern parts of Camp Pendleton. Though much of the recycled water is never drawn up by the distant wells, it forms a sort of underground dam between the aquifers to the east and the salty ocean to the west, Pack said.

The holding ponds are designed to easily handle the more than 5 million gallons of sewage produced on base each day, but they occasionally overflow into nearby streams during periods of heavy rain or unusually large sewage flows.

The base is required to ensure that any effluent flowing into the streams and rivers is as pure as that of surface waters, a requirement that has not always been met of late, Barker said.

Pack said a number of the glitches cited by the regional board are procedural matters that have already been rectified. He anticipates that some of the recommendations yielded in the sewage study can be handled with quick fixes, while more vexing problems may require expensive measures such as construction of new treatment facilities, a process that could be slowed by the federal budgetary process.

Regulated by EPA

Just when the problems began to surface remains unclear. Before May, 1987, the base was regulated by the federal Environmental Protection Agency.

Since then, the state has regulated water quality, and local water board officials have “measured violations virtually since the first day” Camp Pendleton came under the state bailiwick, Barker said. A 1993 deadline has been set for the base to comply with the state rules, he said.

Perhaps the biggest concern, Pack said, is salinity, which can affect the taste of water and harden it, in turn affecting everything from dishwashers to boilers on base.

Aside from hiring a San Diego sanitary engineering firm, Almgren and Koptionak Inc., in October to conduct a study of the sewage situation, the base is also searching for alternative sources of water, such as tapping into the water districts surrounding Camp Pendleton.

More Housing Planned

Pack does not see a need for using imported water soon, but he noted that plans to provide additional family housing on base during the coming decades is likely to change that.

In the meantime, the water being delivered to base personnel, from the lowliest private to the commanding general, is of a high quality, Pack insisted, pointing to a recent study of base water availability and requirements.

“The quality of water aboard the base is as good as or better than much of the water outside,” Pack said. “We intend to keep it that way. We’re not going to mess on our own doorstep.”