Summary of groundwater protection rule

EPA’s 1991 groundwater rule was intended to protect drinking water by regulating the location, design, operation, monitoring and closure of landfills.

Landfills were supposed to be designed and operated as dry tombs to minimize the mobility of the dangerous constituents, and also to include additional layers of defense–

• Located away from airports flood plains, wetlands, and earthquake faults and be more than five feet above aquifers.
• Designed with a composite liner below (2 feet of clay covered with a thin plastic sheet the thickness of a credit card) and similar covers above, along with collection systems to remove leachate and gas, as well as monitoring.
• Operated to restrict hazardous wastes, to be covered daily, to monitor for leaks, and, in order to maintain a dry tomb, not add liquids.
• Closed with a final cover when they fill and for the next 30 years be provided with postclosure care for which financial assurances are to be provided.

Landfill requirements often ignored

The groundwater rule was intended to provide defense in depth, but, too often, that does not happen.

In practice –

• Wetlands. Too often, landfills are permitted in wetlands (Potrero), within flood plains below sea level (Redwood), near earthquake faults (Sunshine Canyon), over sinkholes certain to collapse (Cedar Ridge) and, until a public outcry led the legislature to ban the site, another (Black Bear) was about to be permitted on the Atlantic coast, within the hurricane storm surge zone, where the water table was at the surface, and lifted up on a manmade 50 foot platform.
• Toxics. While industrial hazardous compounds are banned, household toxics are not. Also, many lined landfills have been built on top of unlined and leaking hazardous landfills (Kettleman and Sunshine Canyon).
• Exceptions. In practice, landfills are, sometimes routinely, granted special exceptions to accept industrial hazardous wastes, to add or recirculate liquids in ways that violates dry tomb conditions, and to forgo installation of a seal on top of the landfill.

Essentially, the rule’s criteria, which were intended to reduce some of the risks of burying trash, have often been subordinated to sites favored for economic and political reasons, for their proximity to collection routes or transfer points, or their ability to be easily sited in poor communities – as well as with design and operating compromises that increase profitability with disturbingly insufficient attention to the long-term consequences.

Landfills are leaking long before expected. There is no comprehensive data base of landfill leaks: reports have to be compiled from news accounts. Also, some reported leaks involve sections of landfills that were unlined, although that begs the question of why lined landfills were permitted on top of leaking unlined cells.

Inasmuch as the expected problems with liners that were properly installed at carefully maintained sites lies in the future, the record today fails to reach that larger issue. In any event, examples of landfills that experienced leaks reported by the news media include –

• Waste Management's Tontiown Landfill (Little Rock AR) in 2002
• Waste Management's Cedar Grove Landfill (Cedar Grove TN) in 2009
• Waste Management's Muskego Landfill (Milwaukee, WI), 2009
• Waste Management's Pottstown Landfill (Pottstown, PA), 2005
• Waste Management's Live Oak Landfill (Atlanta, GE), 2005
• Orange County Landfill (Orange County, CA), 1996
• Southeaster Public Service Authority's Suffolk Landfill (Suffolk, VA), 2003
• Safety Kleen's Rimini Landfill (Lake Marion,SC), 2001.

If you know of a leaking landfill, please email us This email address is being protected from spambots. You need JavaScript enabled to view it. , and include any documentation.

Reasons why liners leak. Liner integrity can be compromised over time by–

• Manufacturing mistakes
• Improper installation of the liner the fail to permanently glue one sheet to the next or puncture the liner
• Damage to liner if the first layer of trash at the bottom contains sharp objects or the compacting bulldozers apply too much force
• Household cleaners and paint residues that either permeate or subject the liner to stress cracking
• Leachate that drains to the bottom, fails to drain away and raises a head over the liner.

EPA knew its liner-based rules were flawed. Even composite liners “will ultimately fail” within decades after the agency's post-closure care requirements have expired, they advised, and when the liners fail, “leachate will migrate out of the facility.” Yet, its staff recognized, the duration of a landfill’s hazardous loadings that need to be isolated may be “many thousands of years,” long after the time when discharges will occur.

Why did the EPA nonetheless proceed to rest safety on a flawed technology? The answer is not edifying. “EPA officials,” an investigation by the agency's Inspector General reported a decade later, made the decision “based on a compromise of these competing interests ... not based on specific scientific criteria or research studies.”

Cover damage can lead to site failures. Just under the surface, the cap is vulnerable to being breached any number of ways, such as from heavy rainfall, animals burrowing through and tree roots penetrating the seal. This is what EPA’s Inspector General found in 2001 was already happening routinely from storms and from pigs, bears and marauding teenagers even while the sites were still being managed.

In 1998, a catastrophic cover failure occurred during heavy rains at the Sunrise landfill near Las Vegas. That failure discharged garbage, medical wastes, sewage sludge, asbestos, construction debris and soil contaminated with oil into the Las Vegas wash that feeds Lake Mead, which is the main source of drinking water for Las Vegas and Phoenix and parts of California. Republic Services, the landfill’s operator, vigorously opposed EPA’s order for long term remediation of the site, finally signing a consent agreement in 2008. Clean up costs are estimated at $66 million. (Interestingly, the company was able to afford to give its executives bonuses worth as much as twice that).

Under other provisions of the groundwater rule, after 30 years of postclosure care for closed landfills, they are likely to be abandoned. However, covers will continue to deteriorate from these same causes we are seeing today. But, then, no one will be around to monitor and repair the damage before the site fails.

Liner damage also leads to site failures. The liners that are laid on the bottom of a landfill effectively make the site into a giant bathtub. Since rainfall freely enters the site while it is open to accept trash, and may continue to do so through tears in the cover after it is closed, EPA concluded that a drainage system is essential to prevent accumulating water from damaging the liner and eventually overflowing. Other experts add that rising water also threaten site stability.

To extract the leachate that drains to the bottom of the landfill, perforated pipes, called leachate collection lines, are required to be laid in 20 foot segments about 200 feet apart above the bottom liner in lengths, which extend almost a half a mile in megafills.

Unfortunately, over time pipes this long are difficult-to-impossible to clean out from the ends, and there is no way to clean out the perforated holes if they clog, nor the gravel beds that the pipes are set in.

These pipes can clog up and lose their functionality in several different ways–

• Pipe clog. Microbial and chemical reactions can create blockages inside the pipe and in the perforated holes in the pipe.
• Gravel clog. Gravel drainage beds, which are meant to prevent blockages and maintain flow to the pipes, can themselves clog, especially if the wrong type of gravel is used or if the geotextile screens used to block out debris that would fill the spaces between the gravel itself clogs.
• Joint breaks. At every joint where the 100 or more segments in dozens of long lines are glued together, there is another possible failure point if the glue fails or if the segments were not installed in a straight line.

Maintenance to keep the lines is spotty and often ineffective, and once clogged, little can be done because the cost to dig through so much garbage is prohibitive.

When they do become clogged, leachate will accumulate in growing pools, or “heads” over the liner, weakening its integrity and leading to leaks through the plastic, and, if the head becomes too large, threatening site stability as pore pressures on the liner increase, sheer strength declines and the site becomes to saturated to retain its structural integrity. Sometimes vertical relief wells drilled down into site in an attempt to extract some of the leachate head, but this is rarely effective.

Disturbingly, regulators have studiously avoided any comprehensive investigation of clogging problems, and organized record keeping for citizens to examine is non-existent. But tentative reports suggest that pipe blockages are a common occurrence.