The Manager's report back on a comprehensive report on Gold Star Mothers Memorial Park

Overview of the City’s Approach to Environmental Assessment and Management

The City of Cambridge approaches environmental assessment and management of its parks and open spaces using a risk-based, science-informed framework consistent with state and federal standards. This means that soil testing is performed when there is a reason to believe contamination may be present, such as evidence of prior industrial use, historic filling, or when soil will be disturbed and removed from a site as part of construction.

This approach reflects accepted practice across Massachusetts and other older urban areas, where trace contaminants can exist below ground as a legacy of historic development but are typically isolated from public contact by pavement, turf, or clean soil cover.

In every instance where environmental testing has been performed, the City has acted promptly and transparently, working closely with qualified environmental professionals and regulatory agencies to ensure that all parks meet current health and safety standards. These efforts are part of the City’s broader commitment to maintaining safe, high-quality public spaces while using resources effectively and focusing attention where it provides the greatest public health benefit.

Summary of Full Testing Protocols Used at Gold Star Mothers Park

What We Did: Sampling and Testing

When construction began in the area of the basketball court, crews uncovered buried fill material (ash, brick, concrete, debris) beneath the surface. To support off-site disposal of

this material and understand whether that material posed a risk, the City’s consultant collected soil samples and sent them to a certified environmental laboratory for a broad suite of analyses. These included tests for metals (e.g., lead, arsenic), industrial chemicals (e.g., PCBs and similar compounds), hydrocarbons (oil/grease-type compounds), and other general soil chemistry indicators.

After initial results showed elevated levels of certain contaminants, the investigation expanded to include additional locations across the park (165 locations total). Samples were collected systematically on a grid, at varying depths (near-surface (12” deep) and deeper), to understand both how widespread and how deep the contamination extends.

Monitoring wells were also installed to collect groundwater samples to evaluate whether groundwater is impacted with the same contaminants found in soil, and the potential for contamination to move off-site.

What We Compared Against: Benchmarks and Safety Limits

Laboratory results were compared to established regulatory standards used by state and federal environmental agencies to decide whether further action is required. These benchmarks are intentionally conservative and are designed to provide a large margin of safety when determining whether remediation is needed. When concentrations exceed these regulatory thresholds (sometimes called “reportable concentrations”), state law requires that the findings be reported and that a formal response process be initiated.

In rare cases where contamination could pose a potential short-term hazard, stricter and more immediate response measures apply. Because certain specific locations of the park exceeded these thresholds, the park was fenced off promptly and formal notifications were submitted to the Massachusetts Department of Environmental Protection (MassDEP) for review and approval.

Key Takeaways to Date

Contaminants above regulatory safety thresholds were found in buried fill layers and shallow soils in and around the former basketball court area; deeper soils generally did not exceed thresholds. Sampling elsewhere in the park also revealed elevated levels of certain metals, industrial chemicals, and hydrocarbons in localized areas.

Immediate protective measures, including fencing and restricted access, were implemented while the City continues working with environmental authorities to fully characterize the site and determine appropriate cleanup actions. Groundwater testing results have recently been received and are all below applicable state and federal standards, indicating no evidence of contaminant migration or groundwater impacts.

Timeline and Strategy for Full-Site Testing and Remediation

Design work is underway to guide both the cleanup and long-term improvements to Gold Star Mothers Park. The next phase will involve developing a detailed remediation plan to determine how impacted soils will be managed, whether by removing impacted material, placing clean soil and protective caps over certain areas, or a combination of both.

Because some of the contaminants identified fall under both state and federal jurisdiction, the remediation plan will require review and approval by the U.S. Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection (MassDEP). Coordination with both agencies is already in progress.

Once regulatory approvals are secured, on-site cleanup is anticipated to begin in 2026 or 2027. In the interim, the park will remain fenced and secured, and environmental consultants will continue monitoring and submitting required progress reports to the agencies. Each report will include updates on schedule, findings, and next steps.

Additionally, the City in coordination with regulatory agencies and their environmental consultants, are taking steps to install protective measures over portions of the Park in hopes of reopening these areas to the public more quickly, prior to full reconstruction of the park

Triggers for Environmental Testing in Open Space Construction

Environmental testing during park or open-space construction is typically triggered in two ways: 1. When soil is removed from a site: Whenever a project involves excavation and off-site disposal of soil, state regulations require testing to determine whether the material can be reused, recycled, or must be sent to a licensed disposal facility. These tests screen for potential contaminants such as metals, petroleum compounds, or industrial chemicals. 2.

When field conditions raise concern: Even when testing is not initially required, additional samples are collected if contractors or inspectors observe or smell anything unusual (such as ash, debris, stained soil, or chemical odors) that may indicate contamination.

These procedures are standard practice for public construction projects and help ensure that both the work site and any removed materials are managed safely and in compliance with environmental regulations.

Soil Testing at Other Cambridge Parks and Playgrounds