Groundwater Remediation and Air Quality Monitoring

 

Fall at Closed Ivy Landfill
Closed Ivy Landfill in 2015

One of our most important duties of the Rivanna Solid Waste Authority is to fulfill our post-closure care activities required  by the state and federal government at the site of the Ivy Landfill on behalf of and with financing from the City of Charlottesville and Albemarle County.

State regulations require that landfills monitor the groundwater on their site.  Based on this monitoring at the Ivy Landfill, the RSWA identified specific chemicals that had impacted groundwater quality above health standards.  Although this is not uncommon at similarly-aged landfills, the RSWA has instituted several programs to reduce the level of these impacts and make sure that they do not extend off the property.  These programs included the state-of-the-art technology of enhanced bioremediation through multiple substrate injections to create an ideal underground environment for biological clean-up of impacted groundwater.  The program also includes ongoing groundwater monitoring, to measure the actual results of the remediation, which is expected to continue at least through the remainder of the post-closure care period or until groundwater remediation standards are met.

The program also included the completion of a gas collection piping system for all landfill cells, along with installation of new horizontal drains for two of the landfill cells, to assure that all landfill gas formed underground during the decomposition of the waste can be collected and destroyed at a central location by high temperature burning and flaring, thereby eliminating fugitive emissions that were once a source of odors.  RSWA has received many compliments from neighboring property owners for eliminating odors.

OLYMPUS DIGITAL CAMERA

Installation of Horizontal Drains

 

Installation of Groundwater Remediation Equipment
Installation of Horizontal Drains

 

History

The site was operated as a sanitary landfill from 1968 until 1998, after which construction and demolition debris was accepted until 2001.  The landfill was initially owned and operated by Albemarle County, and then in the 1970s operation was transferred to the City of Charlottesville under a joint arrangement between the City and County with service to both jurisdictions.  When the City and County formed the Authority in 1990, which began operation in 1991, the landfill ownership and operation was transferred to the Authority.  The landfill has been closed since 2001, but because the decomposition of the waste material beneath the closed surface occurs over a much longer period of time, active management and monitoring of site conditions is essential and required by law.

When the landfill opened in 1968, very few state or federal regulations existed which governed the design and operation of landfills.  Over time the need for regulations was recognized and came into effect, governing the need for leachate collection systems, daily cover, vector attraction reduction, “impervious” caps over the top of landfill cells as they are closed, gas management, and active post-closure care.  As regulations matured, new activities at the Ivy Landfill complied with those standards, but older parts of the landfill were “grandfathered” as new regulations went into effect. Older facilities would not meet today’s standards if constructed and operated today.  This condition is an unfortunate reality and all too common among landfills across the country that operated before newer regulations went into effect, and is a major reason why groundwater contamination has occurred at most older landfill sites.

Bioremediation and Ongoing Groundwater Monitoring

In the late 1990s groundwater contamination was discovered at Ivy, contained within the boundary of the landfill property and beyond the footprint of the landfill cells.  A remediation program was developed that began with a “pump and treat” system on the west side, replaced in 2006 by a broader site-wide enhanced bioremediation program.  Enhanced Bioremediation included the injection of carefully selected substrate material into the groundwater to enhance the natural chemical reduction of the contamination to clean groundwater.

As a result of the bioremediation, the spread of contamination within the groundwater on the site has been tightly contained and reduced, protecting both the environment and human health.  The injection of substrate material was suspended in July 2013 to determine if the breakdown of contaminated materials will continue without further injections. The Authority is prepared to re-initiate injections if it proves necessary.  Revisions to the Corrective Action Plan were submitted to the Department of Environmental Quality (DEQ) at that time.  This Plan can be reviewed by clicking on the link below:

2015 Corrective Action Plan (CAP) Revision (Due to size, this document is an excerpt of the original containing Review Comments, Table of Contents, and Executive Summary.  The full version can be obtained by contacting RSWA at (434) 977-2970 x101).

Status

Monitoring of the groundwater and surface water at the site continues.  Groundwater samples are collected and analyzed twice a year and results are reported.  This frequency of monitoring is appropriate given that groundwater moves underground very slowly.  The following most recent reports can be obtain by calling the Moores Creek Administration Office at (434) 977-2970:

  • 2014 Annual Compliance Groundwater Monitoring Report (19,875kb) available upon request
  • Spring 2015 Sentinel Well Monitoring Report (pdf 760kb) available upon request

Because of the wide diversity of material contained in solid waste that was once buried at the landfill, it is not unusual on occasion to discover a constituent in one or more groundwater samples that has not historically exceeded the state standard for groundwater, based on prior sampling, but suddenly exceeds the standard at low concentrations.  During the period between 2004 and 2014, this has occurred with cobalt, and more recently with cadmium.  When this occurs, a Nature and Extent Study is performed to determine if it is tightly contained or more widespread, and if any adverse health effect may result.  In March 2014 the Authority’s report on the Nature and Extent of cadmium presence in groundwater was submitted to DEQ. Fortunately, its presence beyond groundwater standards is very limited (a small area close to Cell 3 Lined), well contained, and of no current effect to human health.  Its presence will continue to be monitored.  The Nature and Extent Study can be obtained by calling the Moores Creek Administration building at (434) 977-2970. Reports are not included here due to their size

Cadmium NES Final (pdf 6.0mb) available upon request

Air Quality

Air quality is also an important part of landfill post closure care, as buried waste material decomposition causes the formation of landfill gases within the waste cells below the ground surface.  Gas build-up can result in pressures that escape through the ground surface.  In 2006 the Authority awarded a construction contract to significantly upgrade the gas collection system for all landfill cells, providing an effective means to pull the formed gas through an underground pipe network to a flare which destroys the methane and other gas components that may cause health or nuisance problems.  Following the upgrade, odor complaints decreased significantly.

The Authority monitors the air quality at the Landfill site annually in August.  Recent reports have been highly favorable.  The most recent report can be reviewed below, summarizing the results of the sampling in August 2015.

2015 Ambient Air Monitoring report (pdf 7mb)

The Authority remains committed to the operation and post-closure care of this facility. For more information on the active remediation at the Ivy Landfill site, please contact the Authority at info@rivanna.org or at (434) 977-2970.