Restoring a neighborhood: radium cleanup eases fears, rebuilds community.
The sites allegedly became contaminated when radium extraction and application industries, operating in the area from about 1913 to 1925, disposed of their wastes (spent carnotite or pitchblende ores, byproducts, etc.) on what was then vacant land. The radium industry was extremely lucrative at the time, since one ounce of radium was worth approximately $3.2 million (in 1921 dollars). The radium was used to coat watch dials or instrument faces so they could be seen in the dark. Much of the industry was funded during World War One to paint markers and dials on ships, planes, and guns. Radium was also used to treat cancer and was even considered to be an elixir of sorts that could heal many different ailments.
Two of the three study areas were local dumps at the time. A 1913 photograph shows one area to be a dump for ash, bottles, and other trash. The waste was used to fill in natural depressions or low areas surrounding streambeds. Houses were then built on top of the fill. In some cases the material was used as backfill against foundations or other building structures such as in-ground oil tanks.
The problem sites were discovered in 1981 when a joint EPA/New Jersey investigation into companies that used or processed radium or thorium came across the U.S. Radium Company. Formerly known as Radium Luminescence, the company was identified as producing the most radium on the East Coast and having sent its waste offsite--since the land surrounding the factory at the time was completely developed. An initial aerial gamma radiation survey identified three main study areas: the towns of Montclair, Glen Ridge, and West Orange. The state, through the Department of Environment and Energy conducted a ground gamma investigation in the summer of 1983, tested indoor radon levels in the fall, and alerted EPA. Consequently a public health advisory was issued in December 1983.
Residents first became alarmed in 1984, following regulatory action that triggered public awareness of excessive indoor radon gas readings, ambient gamma radiation 150 times normal levels (equivalent to 650 chest x-rays a year), and soil radium concentrations up to 2000 times greater than background. The worst contamination was limited to about 150 of the homes, but community concern--and the threat of the unknown--was tremendous. Not only were soils contaminated, but radon--a gas that forms during the decay of radium--with readings as high as 300 pCi/L (100 times the allowable level) in some homes was affecting air quality as well. Because both surficial and deeper soils were found to contain radioactive wastes, runoff and groundwater contamination was feared.
The neighborhoods had witnessed a string of investigations and government promises since they were included on the federal National Priorities List (NPL, or Superfund listing) in 1984. The state initiated a cleanup at some of the priority properties in 1985, but failed to complete the effort because the volume of contaminated soil was underestimated, and potential disposal sites became unavailable. Consequently, residents, previously evacuated from their homes in the major "hot" zones, were unable to return home. Their houses were left abandoned and the crater from the uncompleted excavation fenced off.
Quick Action for the Community
By the time the EPA signed the Records of Decision in June 1989 and June 1990, community fears and outrage had peaked. Reducing indoor radon levels and removing contaminated soils to levels exceeding cleanup criteria were mandated while at the same time an expedited cleanup would be necessary. But the scarcity of information and difficulties inherent in radioactive waste site cleanups--further complicated by the residential setting--presented significant challenges. The magnitude of the problem had become enormous. Estimated costs to clean all of the contaminated areas in the three communities exceeded $250 million. Community leaders lobbied state and federal legislators to get Superfund cleanup funds earmarked for the town, but competition from numerous other sites made this an arduous and slow task.
When it came time to initiate remediation, EPA and the U.S. Army Corps of Engineers (COE), the federal arm involved in most Superfund design and cleanup projects, selected a remedial contractor and outlined a construction schedule that would not begin until summer 1991. Area residents, who perceived another delay, were outraged. To restore public trust, EPA and COE initiated fast-track remediation of several highly contaminated properties. In 1989 Camp Dresser & McKee Inc. (CDM) was contracted to design and oversee a radon mitigation and soil remediation project on an extremely accelerated schedule. The team's objectives were to reduce or remove contamination to acceptable levels at selected properties and provide full environmental restoration. Both short- and long-term solutions were called for. The consultant had performed the remedial investigation and feasibility study for EPA and was already familiar with the issues facing the cleanup team.
Radon Mitigation. The radon mitigation program, an interim action undertaken to reduce radon levels in the most severely affected homes, consisted of:
* Designing and installing systems using underground depressurization to trap radon and vent it aboveground. These systems were installed in homeowners' basements, with minimal disruption to residents.
* Follow-up system evaluation and indoor air sampling, which along with homeowner comments to the EPA (they felt the consultant and the COE were doing an effective job), testified to the program's success. Radon was reduced to normal background levels.
Soil Remediation. The residential property soil remediation effort--more involved, but no less time-constrained--aimed to remediate five contiguous properties in Montclair. More than 5700 cu yd of contaminated soil were removed. Activities included:
* Plans and specifications for home demolition, which involved asbestos removal and disposal, contaminated soil removal, and site restoration, including grading, paving, and landscaping.
* Estimating soil excavation and interpreting existing data. It was determined that sufficient data had already been collected, but that better analysis was needed.
* Ongoing technical support before, during, and after remediation.
The cleanup criteria were adapted from an EPA standard developed for uranium mill tailing sites, "5 pCi/g of radium-226 in the first 15 cm of soil averaged over 100 sq meters and 15 pCi/g in subsurface soil below 15 cm averaged over 100 sq meters." In practice, however, radiation levels were reduced to normal background levels by removing all contaminated material from the site. The asbestos removal was a separate problem. Several of the homes (built in the 1920s and 1950s) contained asbestos around the furnaces, around steam piping, in floor tile, and in roof and exterior wall shingles. Since the homes were being demolished, the friable asbestos had to first be removed and sent to an approved landfill.
An in-depth data collection and evaluation program was conducted concurrent with soil remediation design work. This aided design decisions and helped develop precise soil excavation and material disposal volumes. Soil samples were collected and analyzed both on and offsite.
Accurate Data Critical
Critical to the project's success was accurately estimating the soil volume excavation. The first and only accurate estimate made was within 2.4 percent of the final excavated volume. Although underestimates of 200 to 300 percent for radium-contaminated soils are common, the meticulous data evaluation program resulted in one of the most accurate volume estimates ever achieved for radium remediation.
Several homes in areas of the highest contamination were razed to access the radium-contaminated soils below. After soil removal and backfilling, common-use landscaped areas were developed in their place. Adjacent properties (nearby residences and streets) were carefully protected from demolition work and excavation activities with sheeting and other support measures, such as retaining walls.
Other Site Remedial Work. The site presented many other challenges. Properties contaminated to depths exceeding 12 ft were within 10 ft of sites not scheduled for remediation; environmental media (air, surface water, groundwater) required attention; and normal residential utility services were to be maintained with minimal disruption. Few, if any, cleanups had ever been attempted under such circumstances. These challenges were met by providing:
* Alternate electric, water, and gas utility routings.
* Excavation schedules and testing procedures that accounted for ambient gamma radiation "shine."
* Equipment and personnel decontamination pads.
* Runoff into pits and groundwater encountered in excavations required contamination protection measures. Similarly, the design included preventing airborne radionuclide-contaminated dust and particulates from going off the work properties onto adjacent homes.
Environmental Considerations. Because all upstream runoff was redirected away from the site during cleanup there was minimal impact on groundwater. Also working in our favor was that the groundwater table was not encountered during excavation work. Well-timed rains kept the soil moist and limited dust migration.
Decontamination Pad. This was built in the street using railroad ties with asphalt ramps on the ends and a berm on the high side. Vehicles leaving the site drove up and were pressure-washed. Water and sediment were collected in lined sumps cut into the street's low areas, stored, and then disposed of according to current standards.
Radiation "Shine." Gamma radiation "shine" refers to the fact that the properties in the core area of contamination were surrounded by other contaminated materials in adjacent properties and beneath adjoining roads. Even if all of the contaminated soil in the main project area was removed, field gamma scintillation equipment would detect gamma radiation from the adjacent areas. Previous remedy attempts had specified that the contractor dig until the detecting equipment indicated that background or some specified gamma level was reached. In this situation such an approach would not work. We did not control the shine, but designed the remediation to account for it. The remediation proceeded in two phases. The "primary" cut included soils to be removed no matter whether it was contaminated or not. Then the contractor was to analyze the soil to determine if it met cleanup criteria. If not, a series of "secondary" cuts took place, with soil analyzed after each.
To streamline the design phase and ensure that excavation cuts reflected current site conditions, CDM provided a concurrent data collection and evaluation program, feeding data to the designers and obtaining intermittent EPA/COE design approval. Existing survey information, background levels, and radiological data were compared to concentration determinations collected and analyzed onsite to map the final excavation lines.
Comprehensive Environmental Approach
Though tasked only with soil and radon gas remediation, all environmental media, including air, surface water, and groundwater, were considered. Soil excavation design included provisions to minimize runoff and groundwater contamination from contaminated upgradient properties, and dust control measures to prevent dispersion of airborne contaminants. Special decontamination pads and procedures were used to eliminate risk to residents and onsite workers. The project team even undertook a radiological scan of all home contents to determine which items required decontamination before being returned to homeowners. Throughout the effort, the team worked to keep concerned residents apprised to progress and address their needs where possible during design. Residents were informed by the EPA site manager who called or visited them to get their comments on the designs. The residents also had the opportunity to review the final design drawings.
CDM integrated community relations into the project and addressed residents' concerns for human health protection, utility connections during remediation, and an esthetically appealing restoration. Even now, with the threat of radon poisoning receded and levels reduced to normal, we provide ongoing sampling assistance upon resident request. This project showed that radiation cleanup could be successfully planned and designed, and with effective construction management, demonstrated to the residents that a smooth, full-scale town cleanup could be completed. Final remediation costs for the "hot zone" project totalled just over $7.28 million.
As a result, the neighborhood has been not only environmentally restored, but "emotionally" restored as well. Where once-contaminated soils and escaping radon gas threatened health and welfare, residents now enjoy a public park. Property values, once plummeting uncontrollably, have risen, with added benefit from the landscaping and other improvements. Many residents, who joined hands in the face of their decade-long environmental nightmare, have experienced a new-found kinship, security, and sense of pride in their renewed community. Montclair homeowners have recovered their peaceful quality of life.
Ms. Ranney is a Principal Scientist and Mr. Gaddis is a Principal Engineer with Camp Dresser & McKee Inc. in Edison, New Jersey. Both served in task/project management roles for the Montclair cleanup.
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|Title Annotation:||Essex County, New Jersey|
|Author:||Ranney, Colleen A.; Gaddis, David M.|
|Date:||Jul 1, 1993|
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