At GHS: Town presents solutions to contamination

A year and a half after the discovery of contaminated soil forced the closure of GHS fields, the town is now considering options to clean it up.— Paul Silverfarb photo

A year and a half after the discovery of contaminated soil forced the closure of GHS fields, the town is now considering options to clean it up.
— Paul Silverfarb photo

Contaminated fields at Greenwich High School have been a community concern since 2011, and at a special meeting addressing the issue Wednesday night, town and regulatory officials presented various solutions to the problem.

Gathering at Central Middle School, Superintendent of Schools William McKersie, Greenwich Commissioner of Public Works Amy Siebert, Board of Education Chairman Leslie Moriarty, and several officials from AECOM, an outside firm brought in by the town for this project, offered the community an open house and formal presentation in order to openly discuss the results of tests and risk assessments performed on GHS fields, along with options for remediation.

AECOM employee Malcolm Beeler assured those in attendance that a comprehensive environmental study of the GHS site was conducted before officials began to contemplate options for contamination removal.

“We’re not just dealing with one corner or another, we’ve looked at the entire site,” Mr. Beeler said.

Options suggested

Options for remediation introduced at Wednesday’s presentation included removal to the strictest standard and self-implementing remediation, each of which would require extensive excavation of the site and could cost anywhere from $50 to $180 million and five to 12 years to carry out. Also presented were risk-based remedial options, which aim to reduce health risks to site users and take into account current and future use of the grounds while maintaining reasonable cost and production time.

Risk-based option number one would involved the excavation of soils to create a one-foot barrier of clean soil in contaminated areas. In Area of Concern one (AOC-1) — the 16-acre portion of the GHS grounds most impacted by contamination —  the natural grass would be included in the excavation but turf fields would be left as is because they already serve as barriers to the impacted soil. In Area of Concern 13 (AOC-13), crews could work around most trees, saving many of them, and other small, limited areas on the grounds would also be excavated. The option would take one to two construction seasons — GHS’s summer break from late June to late August — to carry out and would provide a major reduction in risk to site users. There would, however, be strict site restrictions in this method of remediation because any construction performed below the one-foot clean barrier would require an evaluation of site conditions so that work could be done safely. The cost would be $7 to $12 million.

Risk-based option two would be similar to option one except that a three-foot barrier, rather than a one-foot barrier, of clean soil would be created across a large portion of the site. This would include excavating under turf fields and would require the removal of more trees than option one. The process would take two or more construction seasons to complete and allow for many fewer site restrictions, so that field maintenance work could be completed as needed without concern. The option’s price tag would come to a total of $27 to $45 million.

Option three favored

Based on current knowledge and conditions, AECOM recommends that the town choose risk-based option three, which would address limited risk concerns to identified site users and would eliminate certain site restrictions that are currently in place, meaning routine activities and limited future work on the site could be performed without the current constraints. The option includes excavation of the site at varying depths, depending on what different areas on the site are currently and would potentially be used for. For example, according to Mr. Beeler, areas where utilities might be installed in the future would be excavated to three feet rather than one foot to assure that such an installation could be done safely.

The option would allow the town to greatly reduce potential health risks on the fields and leave in place only reasonable site restrictions, allowing for routine work to be performed, Mr. Beeler said. The process would take place over approximately two construction seasons and would cost between $13 and $20 million, he said.

In preliminary discussions with environmental regulatory agencies such as the Connecticut Department of Health and the Environmental Protection Agency (EPA), regulators indicated to AECOM that risk-based option number three could be acceptable and that they would be willing to discuss the option seriously, Mr. Beeler said. The more dramatic options, such as removal to the strictest standard, would have a major impact on the larger Greenwich community, he said. With significant removal of soil, there would be approximately 60 trucks per day going on and off the GHS site and, accordingly, driving through the town five days per week. AECOM’s recommended option carries a shorter time frame and less community impact while maintaining a reasonable price tag, Mr. Beeler said.

“We consider it to be a cost-effective effort for the amount of risk reduction that you get,” he said.

Additionally, Mr. Beeler said, the option includes maintenance of the site. Once the fields are treated, they will need to be maintained in order to remain effective, so the option ensures that the grounds and surface water on the site would continue to be inspected and monitored to verify that contamination impacts are not migrating off-site.

Groundwater

Another factor to consider on its own is groundwater contamination, Mr. Beeler said. Site monitoring currently indicates that impacts to groundwater are centralized and not migrating off-site, so remediation of groundwater would be deemed necessary only if measurable changes in site conditions occurred, he said. The process would likely require source removal, resulting in a deep excavation that would create a hole approximately 200 feet wide, 560 feet long and 13 feet deep. Completion of source removal would take five or more construction seasons and would cost $30 to $35 million in addition to soil remediation costs. AECOM does not include source removal as part of its remediation recommendation, Mr. Beeler said.

With such “complex and highly technical” information to consider, Dr. McKersie told attendees, he has used four standards to “make sense of this.” They are the standards he brings to any emotional, complex issue that relates to young people, he said.

“That’s the business of education,” Dr. McKersie said.

The first thing to consider is the standard for health and safety for anyone in and around GHS, which is already “set at an incredibly high level.” The second point to consider is what evidence is available. Historically, Dr. McKersie said, school-related arguments of this nature have been made on narrow evidence, which is not the case with the high school’s current contamination issue. There are multiple types of evidence to review, which is “very assuring,” he said.

The third thing to consider is what level of expertise is being brought to the issue, which in this case is multi-dimensional and includes public, private, state, and federal expertise, Dr. McKersie said. Finally, the issue of transparency is of utmost importance, he said. In environmental and educational policy there are many things that go unshared, which is not the case in this situation. It is “incredibly transparent … a lot of effort has gone to that and will continue to go to that,” he said. In consideration of each of these four standards, Dr. McKersie said, the issue of remediation can be evaluated with more ease.

Q&A

Following Dr. McKersie’s comments was an audience Q&A session that addressed questions and concerns that people posted online and asked at the presentation. A number of the questions pertained to results from the environmental testing done at GHS, and Mr. Beeler reminded attendees that the remedial investigation report is available online at greenwichschools.org/page.cfm?p=10019 and provides all results collected from testing from 2011, when the contamination was discovered through the environmental investigation conducted last summer.

One resident asked what the maximum contamination levels of the fields were in relation to safe exposure guidelines for children. AECOM’s Julie Kabel, a human health risk assessor, explained that the EPA’s screening levels for children are intended for a residential scenario, which assumes that a child is home 24 hours per day, 350 days per year until the age of 30. Under the circumstances at GHS, there are no default screening levels for children because they do not live on site, Ms. Kabel said. Accordingly, a human health risk assessment was conducted at GHS that ultimately showed no unacceptable risk levels to children at the school.

Another resident asked if there was any risk to humans and plants living near GHS, given that water flows through that site and onto other properties. Ms. Kabel reiterated that the ecological risk assessment of the grounds showed that surface water leaving the site did not exit above any conservative screening levels, which means properties neighboring GHS are not expected to contain contamination above screening levels, and the same principle applies to nearby plants.

With a range of remediation options available, one member of the community asked who would ultimately decide which alternative to apply. Greenwich Commissioner of Public Works Amy Siebert explained that a great deal of time and energy had already been spent using all of the data gathered from the remedial investigation and adding stakeholder input to it from such groups as the Parks and Recreation Department, the Board of Education and the community. The town elected to have AECOM propose an option recommendation in order to have a place to start based on what’s protective of human health and environment, what will work long-term and what makes sense given the town’s knowledge of how the GHS fields are used, Ms. Siebert said.

Budgets are also being put together with the Board of Estimate and Taxation and the Representative Town Meeting to help assist in making a choice. Essentially, a number of groups will end up having helped make a final decision, Ms. Siebert said.

Another question was whether the town legally has minimum requirements for remediation. Ms. Siebert explained that there was no chance that the town would not take some course of action. The interim remedial measures currently in place, such as added fencing, need to be eliminated so that a return to routine maintenance of GHS fields can be achieved. The town wants to ensure that the Parks and Recreation Department will not have to carry out certain procedures that they are currently subject to and that all involved are comfortable with the condition of the site, Ms. Siebert said.

At the conclusion of Wednesday’s meeting, Kim Eves, director of communications for the district, reminded attendees that their input was valuable and that comments and questions about remediation options could be made online at greenwichpublicschools.org/page.cfm?p=10915 through April 30.

 

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