Sea Level Rise Guidance to DTSC Project Managers for Cleanup Activities

Sierra Club Bay Alive

October 30, 2023

Department of Toxic Substances Control
1001 I Street
Sacramento, CA 95814
Transmitted via email to DTSC_SeaLevelRise@dtsc.ca.gov

RE: Sea Level Rise Guidance to DTSC Project Managers for Cleanup Activities

The Sierra Club’s Bay Alive Campaign welcomes this opportunity to comment on the proposed Sea Level Rise Guidance to DTSC Project Managers for Cleanup Activities (Guidance). We do so on behalf of more than one hundred thousand Sierra Club supporters in the three chapters surrounding San Francisco Bay: Loma Prieta Chapter, San Francisco Bay Chapter, and Redwood Chapter. Together, our mission is to protect the health of our communities, our wildlife and our Earth by promoting living shorelines, healthy waters, and just, equitable, and economically beneficial solutions to sea level rise in the San Francisco Bay Area. We advocate for the multi-layered benefits of natural and nature-based adaptation to sea level rise, for regional coordination, and for equitable strategies to build community resilience. We contribute to plans, guidance, and actions under consideration at local, regional, and State levels. In addition, we provide Bay-educational webinars by topic-expert presenters for advocates, community leaders and city/county staff and elected officials1 and train new advocates through our eight to twelve week Bay Advocate Programs.

As sea levels rise worldwide due to climate change, the San Francisco Bay will experience increased flooding along its shorelines, as well as groundwater rising in some areas. These impacts will not only increase the risk of property damage and the loss of wetlands critical to Bay ecology and climate mitigation capacity, but can also transport hazardous chemicals from old industrial sites ringing the Bay, posing a health risk to residents and Bay ecosystems alike. A 2012 White Paper from the California Energy Commission’s California Climate Change Center identified more than 200 hazardous waste sites along the Bayshore that will be in a 100-year flood zone with a 3-foot sea level rise. Most of the identified vulnerable sites are in San Mateo, Santa Clara, and Alameda Counties2.

We were pleased to see the California Department of Toxic Substances Control (DTSC) issue draft Guidance for their Project Managers on how to incorporate future sea level rise (SLR) into hazardous waste site remediation planning and implementation. Importantly, the Guidance applies not only to sites currently undergoing remediation planning and implementation, but also to sites that have already completed all required remediation but leave hazardous wastes still in place. Nonetheless, we believe the Guidance lacks the necessary specificity to ensure consistent interpretation and application of the Guidance, as well as public clarity about the criteria for certain determinations and mechanisms for accountability.

We offer the comments below in the spirit of collaboration to strengthen the Guidance for long-term efficacy that benefits Bay-wide shoreline communities and ecosystems.

  1. Clarify criteria for requiring a SLRVA and scope of analysis

The guidance gives wide latitude to individual DTSC project managers to determine whether a Sea Level Rise Vulnerability Assessment (SLRVA) should be conducted, and how extensive the study must be. This creates significant risk of inconsistent application of the Guidance. The Guidance should provide clear criteria for determining the need for a SLRVA and provide explicit requirements for determining the appropriate scope of analysis.

  1. Add requirements for hydrogeology assessments

Although the guidance states that groundwater rise should be addressed in a SLRVA, there is no requirement to conduct a groundwater hydrology study as part of that process. Without that information, it is impossible to apply the best available science for remediation. Groundwater rise has been found to impact areas further inland than surface water flooding.3 Unfortunately, we lack current data about the hydrogeology of much of the Bay Area. A recent report by the San Francisco Estuary Institute and Pathways Climate Institute makes a strong case that “an understanding of hydrogeology should be integral to coastal zone management and adaptation.”4 A groundwater hydrology study should be mandatory for any site where the remediation actions result in hazardous chemicals remaining in the subsurface above levels protective for residential use or ecological harm.

  1. Clarify process, mechanisms, and responsibility for identifying “new information” and determining when remedial actions need to be modified

The guidance includes a “Protectiveness Determination” that allows remedial actions to be modified at any phase of the cleanup process (planning, active remediation, post-closure) by initiating a new SLRVA if measures are found to be inadequate. However, it fails to articulate the mechanism(s) for discovering and sunlighting relevant new information or how an adequacy determination would be made. The Guidance should be more explicit about how this process can be initiated, what kinds of new information could trigger it, whether community groups or others could provide new data to justify reevaluation, and how such information can be submitted by outside parties for DTSC consideration.

Community input should be a key factor in protectiveness determinations, but it also is incumbent upon DTSC to proactively require action by responsible parties to identify weaknesses in light of the latest sea level rise science, potential hazardous materials of current concern that were not considered in the original remediation plan, and changes to baseline conditions at any given site that can be reasonably anticipated.

  1. Caps and gray infrastructure are ineffective to control the spread of soil borne toxins due to groundwater rise

The Guidance recommends remedial measures such as caps, seawalls, and levees, which can be ineffective at preventing contaminants remaining in soil from being transported to the surface or into drinking water aquifers or into sensitive wetland ecosystems by rising groundwater5. Strong preference should be given to remediation measures such as in-situ treatment or waste removal that reduce risks from groundwater rise as well as from surface water flooding.

  1. Guidance should rely on the most current, high risk-aversion SLR projections and consider exacerbating conditions on the Bay side that may not be reflected in OPC modeling

The Guidance bases the SLRVA process on a 2018 report by the Ocean Protection Council (OPC) that modeled SLR for 12 sites along the California ocean shoreline. Applicability of those data to the Bay and other estuaries are uncertain, as high water levels can be increased by storm surges and creek outflows. The Guidance should require consideration of those extreme events in SLRVAs for estuarine sites and be revised in a timely fashion to reflect any updates to OPC’s projections and guidance.

Additionally, due to the health and safety threat to both people and Bay and riverine ecosystems from toxins mobilized due to sea level and groundwater rise, DTSC Guidance should call for remediation strategies that meet planning guidelines for the highest risk-aversion.

  1. Promote coordination for a unified approach to remediation management related to sea level rise.

The Guidance applies only to hazardous waste sites for which DTSC is the lead agency for managing remediation; however, there are many more sites where the lead agency is the State Water Resources Control Board, including Regional Water Quality Control Boards operating under its authority, or a local agency such as a County. The Guidance should include policies to promote a unified approach to SLR across these agencies and also require DTSC staff to follow the Guidance when commenting or approving plans from another agency.

Thank you for considering our comments. We look forward to responsive adjustments to DTSC’s Sea Level Rise Guidance.


Sincerely,

Arthur Feinstein
Chair, 3-Chapter Sea Level Rise Committee
Bay Alive Campaign

Gita Dev
Vice-Chair, 3-Chapter Sea Level Rise Committee
Bay Alive Campaign

cc:
Jennifer Chang Hetterly
Bay Alive Coordinator
Sierra Club Loma Prieta Chapter

Brandon Dawson
Director
Sierra Club California

1 See for example: https://www.sierraclub.org/sf-bay-alive/sea-level-rise-webinar-why-we-need-nature-based-adaptation

2 Heberger, M., Cooley, H., Moore, E., Herrera, P., 2012. The Impacts of Sea Level Rise on the San Francisco Bay [White paper]. California Energy Commission. CEC‐500‐2012‐014. https://pacinst.org/wp-content/uploads/2018/08/sea_level_rise_sf_bay_cec3.pdf; Hill, K., Hirschfeld, D., Lindquist, C., Cook, F., and Warner, S. 2023. Rising coastal groundwater as a result of sea-level rise will influence contaminated coastal sites and underground infrastructure. ResearchGate. 10.22541/essoar.168500245.55690018/v1

3 May CL, Mohan A, Plane E, Ramirez-Lopez D, Mak M, Luchinsky L, Hale T, Hill K. 2022. Shallow Groundwater Response to Sea-Level Rise: Alameda, Marin, San Francisco, and San Mateo Counties. Prepared by Pathways Climate Institute and San Francisco Estuary Institute. doi.org/10.13140/ RG.2.2.16973.72164, 3; Hill, Hirschfeld, et. al. Rising coastal groundwater as a result of sea-level rise will influence contaminated coastal sites and underground infrastructure. ResearchGate. 10.22541/essoar.168500245.55690018/v1

4 May, Mohan, Plane, et. al., Shallow Groundwater Response to Sea-Level Rise, 2-3.

5 Plane, E., Hill, K., and May, C. 2019. A Rapid Assessment Method to Identify Potential Groundwater Flooding Hotspots as Driven by Sea Levels Rise in Coastal Cities. Water 2019, 11(11), 2228; https://doi.org/10.3390/w11112228