PCE Contamination
Public Notice of Groundwater Investigation and Recommendation to Sample Private Water Supply Wells
Central Coast Regional Water Quality Control Board, June 22, 2021
Central Coast Regional Water Quality Control Board, June 22, 2021
December 7, 2020 Letter to Board of Supervisors
After we discovered the presence of PCE contamination of the 1500 Capitola Road parcel (initially as a Consent Agenda item in the November 10 Board of Supervisors meeting agenda), we submitted the following letter for inclusion the December 8 Consent Agenda item regarding the extended negotiation period for the agreement with Mid-Pen Housing:
Dear Supervisors ~
After reviewing your 11/10 meeting video and supporting documents we have the following comments to make for your 12/8 Consent Agenda Item 35, even though it is mainly a housekeeping action to continue the already approved project moving forward.
At the outset, although supportive of the final plan that was created for the parcel, we were quite surprised that the information about chemical contamination at the site, the extensive testing, the plans for addressing the health impact problem, plus a change in the sale price of the Redevelopment parcel, was placed on the Consent Agenda! Especially since the public has shown consistent interest in this project. This new situation is serious. The County has known about it for most of the year. Yet the public had to learn about it by reading through a long Consent Agenda packet three days before the 11/10 meeting.
The County wonders why it is often times dinged for lack of transparency. Having this pop up on the 11/10 Consent Agenda item was a clear example!
We reviewed the documents provided in the BOS 11/10 agenda item packet. Then we reviewed the situational problem that was encountered during the testing for MBTE at the beginning of the year. Consultants went looking for groundwater pollution (" ... detectable residual hydrocarbon contamination from the former Live Oak Texaco at 1671 Capitola Road has spread in groundwater and possibly soil vapor, beneath the 1514 Capitola Road parcel.") and instead found PCE (tetrachloroethylene).
We learned that follow‐up sampling of soil, soil gas, and groundwater samples: a) Confirmed encroachment of dry cleaning solvent contamination from the adjoining property to the east, and b) Provided data needed for the design of a vapor barrier system for the proposed multi‐ use development project. From the report to the Board, "The collected testing data, groundwater gradient direction, and land use records provide overwhelming evidence that PCE contamination has encroached onto the proposed development property (1412-1514 Capitola Road) from the adjoining, former dry cleaner parcel (1600 Capitola Road)."
We then spent several hours on research about PCE contamination of land, air and water systems.
Per the SF Bay Regional Water Quality Control Board Fact Sheet: Development on Properties with a Vapor Intrusion Threat (July 2019) (Click HERE for this document) ‐‐ "These VOCs can pose a health threat to building occupants if they migrate into buildings through vapor intrusion (VI)." This leads us to ask several questions, the answers to which were not discussed at your 11/10 meeting:
Sincerely,
Jean Brocklebank
Michael Lewis
________
Research Notes:
SF Bay Regional Water Quality Control Board
Fact Sheet: Development on Properties with a Vapor Intrusion Threat ‐ July 2019
"These VOCs can pose a health threat to building occupants if they migrate into buildings through vapor intrusion (VI)."
"However, we recognize that achieving cleanup standards may take years given currently available remedial technologies, and therefore interim protective measures may be needed. Typically, VI mitigation systems (VIMS) are installed in the interim to mitigate VI threats. VIMS are not a substitute for cleanup."
For vented VIMS, ongoing monitoring of contaminant concentrations (subslab and/or indoor air) is needed to demonstrate effectiveness. Long‐term monitoring of indoor air can be problematic because it requires access permission, is intrusive to occupants, and data interpretation can be challenging due to confounding factors from indoor and outdoor sources of VOCs. For SSDS, the measurement of cross‐slab vapor pressure differential can be used to monitor if subsurface vapors are migrating into the building. Pressure differential monitoring can provide real‐time, continuous readings more cost effectively than indoor air monitoring. This reduces the need for long‐term indoor air monitoring except as a contingency measure.
Soil vapor monitoring near the source of pollution where the VIMS is installed provides the best evidence to evaluate the VI threat and evaluate when VIMS are no longer needed. VIMS operation can be discontinued when we determine that the VI threat has ceased.
https://www.colorado.gov/pacific/sites/default/files/HM_hw‐drycleaner‐pce‐factsheet.pdf
PCE evaporates easily. Therefore, ground water contaminated with PCE can “vent” PCE vapors into the soils above. Indoor air in overlying structures, such as homes, can become contaminated with PCE as it makes its way through cracks in foundations and crawl spaces.
Tests done at several locations in Colorado reveal that PCE is found in the indoor air of many homes, even those unaffected by any nearby sources such as dry cleaners. These “background” levels of PCE are often derived from household products such as cleaning chemicals that are stored within the home or from recently dry cleaned clothing. In cases where a home may be located over ground water contaminated with PCE, it may be difficult to determine with certainty whether the measured vapors are the result of an indoor air source or ground water contamination.
PCE is heavier than water, it will sink in any aquifer or be at the bottom of groundwater areas.
http://ustlowriskpolicy.org/wp‐content/uploads/2012/03/07.18.11‐Remediation‐of‐ Drycleaning‐Sites‐in‐California‐3.0‐FINAL‐with‐cover.pdf
1980 Perc use in the USA peaks, with dry cleaners as the main users. 1990 US EPA proposes national emission standards to limit PCE emissions from drycleaning plants. 1995 The first state drycleaning site remediation program begins, in Florida. 1998 The State Coalition for Remediation of Drycleaners is established, with US EPA Superfund support. 2001 California deems perc a toxic chemical. 2006 CARB votes to phase out perc use in drycleaning by 2023. In 2008 the State of California began a 15‐year phase out of perc, the first of its kind in the nation. The existence of this program is in uncomfortable contrast to the fact that California does not yet have a statewide program for remediation of current and former drycleaning sites affected by perc contamination of soils and groundwater. Such programs exist in 13 other states, with the earliest dating back to the mid‐1990s.
Other chemicals used by dry cleaners that have entered soils and groundwater include glycol ethers, naphtha, silicon‐based solvents, hydrocarbons, ‘mahogany’ or petroleum sulfonates, sodium sulfosuccinates, sodium alkylarenesulfonates, amine alkylarenesulfonates, fatty acid esters of sorbitan, etc., ethoxylated alkanolamides, ethoxylated phenols, and ethoxylated phosphate esters4 ; flame retardants, stain repellants, oxidizing bleaches, reducing bleaches, and plasticizers. Highly complex and unpredictable chemical cocktails in soils, groundwater and drinking water supplies cannot all be tested for, much less understood, or even fully quantified. These chemicals also mix and react with other natural and anthropogenic substances in soils, groundwater, public supply water and ecosystems. Complexity and cost of decontamination at a particular site is in general a function of time since release(s) occurred. As time goes on, soil contamination leads to groundwater contamination, with individual plumes commingling over broad areas, creating more and more complex contamination/decontamination environments and scenarios.
Perc enters the soil and thus groundwater and water supplies in three ways: airborne perc precipitates from the air in rain; perc leaks onsite and migrates downwards; and, perc‐bearing liquids are disposed of in drains and waste pipes ‐ many of which are unsealed or cracked. Perc is resilient and difficult to contain, seeping into the ground until it reaches rock or clay, which may be 40 feet or more below the surface. In some cases plumes spread over the course of decades, and have been known to spanned areas of up to 19 miles. Once it has entered groundwater, perc and its breakdown products are difficult to remove.
Perc is extremely pervasive and recalcitrant, concentrating in ecosystems and food chains. Even small amounts of perc in the water are toxic to aquatic animals, which store the chemical in their fatty tissues10. Some of these animals are human food sources. Perc shows up in: dairy products, meats, oils and fats, beverages, fruits and vegetables, fresh bread, fish, shellfish and marine mammals ‐ as well as rainwater, sea water, rivers, groundwater, commercial deionized charcoal‐filtered water11.
https://documents.geotracker.waterboards.ca.gov/regulators/deliverable_documents/72686287
76/Email%20Request%20‐ %20New%20Dry%20Cleaner%20Release%20Site%20(1600%20Capitola%20Road,%20Sant a%20Cruz)_04‐23‐2020.pdf
https://documents.geotracker.waterboards.ca.gov/regulators/deliverable_documents/72686287 76/EXAMPLE%20Explanatory%20letter%20from%20the%20Water%20Board%20(off‐ site%20responsibility).pdf
The Central Coast Water Board does not have direct authority to allow or deny development or land use change proposals for polluted properties; this authority resides with local land use permitting authorities. Therefore, for the Property:
August 2020 letter to Chang, giving him the bad news ... "However, the responsible party (i.e. the property owners) are retired, without funds, and will need to obtain State grant monies, which may take a number of years to qualify."
After reviewing your 11/10 meeting video and supporting documents we have the following comments to make for your 12/8 Consent Agenda Item 35, even though it is mainly a housekeeping action to continue the already approved project moving forward.
At the outset, although supportive of the final plan that was created for the parcel, we were quite surprised that the information about chemical contamination at the site, the extensive testing, the plans for addressing the health impact problem, plus a change in the sale price of the Redevelopment parcel, was placed on the Consent Agenda! Especially since the public has shown consistent interest in this project. This new situation is serious. The County has known about it for most of the year. Yet the public had to learn about it by reading through a long Consent Agenda packet three days before the 11/10 meeting.
The County wonders why it is often times dinged for lack of transparency. Having this pop up on the 11/10 Consent Agenda item was a clear example!
We reviewed the documents provided in the BOS 11/10 agenda item packet. Then we reviewed the situational problem that was encountered during the testing for MBTE at the beginning of the year. Consultants went looking for groundwater pollution (" ... detectable residual hydrocarbon contamination from the former Live Oak Texaco at 1671 Capitola Road has spread in groundwater and possibly soil vapor, beneath the 1514 Capitola Road parcel.") and instead found PCE (tetrachloroethylene).
We learned that follow‐up sampling of soil, soil gas, and groundwater samples: a) Confirmed encroachment of dry cleaning solvent contamination from the adjoining property to the east, and b) Provided data needed for the design of a vapor barrier system for the proposed multi‐ use development project. From the report to the Board, "The collected testing data, groundwater gradient direction, and land use records provide overwhelming evidence that PCE contamination has encroached onto the proposed development property (1412-1514 Capitola Road) from the adjoining, former dry cleaner parcel (1600 Capitola Road)."
We then spent several hours on research about PCE contamination of land, air and water systems.
Per the SF Bay Regional Water Quality Control Board Fact Sheet: Development on Properties with a Vapor Intrusion Threat (July 2019) (Click HERE for this document) ‐‐ "These VOCs can pose a health threat to building occupants if they migrate into buildings through vapor intrusion (VI)." This leads us to ask several questions, the answers to which were not discussed at your 11/10 meeting:
- What kinds of PCE vapor release will occur as soon as pre-construction site work
- commences (leveling and trenching for underground utility services)?
- How will workers and those who live adjacent to the parcel be protected from potential vapor releases over the duration of the construction project?
- How will vapor intrusion be mitigated on the entire parcel (not just the buildings), where a children's playground area, the community gardens, and a public commons are proposed?
- What about testing on other residential parcels to the south and southeast?!
- Shouldn't there be some kind of epidemiological study of the health of residents outside the Successor Agency parcel?
- There are existing residences that may be affected by the underground contamination. Does the County owe the health of these folks some kind of attention? At the very least, a personal contact to alert them of the potential problem.
- How will this contamination eventually be cleaned‐up (decontamination/site remediation)? Or won't it?
- We think these questions and their answers matter as much as the very good proposed and approved project matters.
Sincerely,
Jean Brocklebank
Michael Lewis
________
Research Notes:
SF Bay Regional Water Quality Control Board
Fact Sheet: Development on Properties with a Vapor Intrusion Threat ‐ July 2019
"These VOCs can pose a health threat to building occupants if they migrate into buildings through vapor intrusion (VI)."
"However, we recognize that achieving cleanup standards may take years given currently available remedial technologies, and therefore interim protective measures may be needed. Typically, VI mitigation systems (VIMS) are installed in the interim to mitigate VI threats. VIMS are not a substitute for cleanup."
For vented VIMS, ongoing monitoring of contaminant concentrations (subslab and/or indoor air) is needed to demonstrate effectiveness. Long‐term monitoring of indoor air can be problematic because it requires access permission, is intrusive to occupants, and data interpretation can be challenging due to confounding factors from indoor and outdoor sources of VOCs. For SSDS, the measurement of cross‐slab vapor pressure differential can be used to monitor if subsurface vapors are migrating into the building. Pressure differential monitoring can provide real‐time, continuous readings more cost effectively than indoor air monitoring. This reduces the need for long‐term indoor air monitoring except as a contingency measure.
Soil vapor monitoring near the source of pollution where the VIMS is installed provides the best evidence to evaluate the VI threat and evaluate when VIMS are no longer needed. VIMS operation can be discontinued when we determine that the VI threat has ceased.
https://www.colorado.gov/pacific/sites/default/files/HM_hw‐drycleaner‐pce‐factsheet.pdf
PCE evaporates easily. Therefore, ground water contaminated with PCE can “vent” PCE vapors into the soils above. Indoor air in overlying structures, such as homes, can become contaminated with PCE as it makes its way through cracks in foundations and crawl spaces.
Tests done at several locations in Colorado reveal that PCE is found in the indoor air of many homes, even those unaffected by any nearby sources such as dry cleaners. These “background” levels of PCE are often derived from household products such as cleaning chemicals that are stored within the home or from recently dry cleaned clothing. In cases where a home may be located over ground water contaminated with PCE, it may be difficult to determine with certainty whether the measured vapors are the result of an indoor air source or ground water contamination.
PCE is heavier than water, it will sink in any aquifer or be at the bottom of groundwater areas.
http://ustlowriskpolicy.org/wp‐content/uploads/2012/03/07.18.11‐Remediation‐of‐ Drycleaning‐Sites‐in‐California‐3.0‐FINAL‐with‐cover.pdf
1980 Perc use in the USA peaks, with dry cleaners as the main users. 1990 US EPA proposes national emission standards to limit PCE emissions from drycleaning plants. 1995 The first state drycleaning site remediation program begins, in Florida. 1998 The State Coalition for Remediation of Drycleaners is established, with US EPA Superfund support. 2001 California deems perc a toxic chemical. 2006 CARB votes to phase out perc use in drycleaning by 2023. In 2008 the State of California began a 15‐year phase out of perc, the first of its kind in the nation. The existence of this program is in uncomfortable contrast to the fact that California does not yet have a statewide program for remediation of current and former drycleaning sites affected by perc contamination of soils and groundwater. Such programs exist in 13 other states, with the earliest dating back to the mid‐1990s.
Other chemicals used by dry cleaners that have entered soils and groundwater include glycol ethers, naphtha, silicon‐based solvents, hydrocarbons, ‘mahogany’ or petroleum sulfonates, sodium sulfosuccinates, sodium alkylarenesulfonates, amine alkylarenesulfonates, fatty acid esters of sorbitan, etc., ethoxylated alkanolamides, ethoxylated phenols, and ethoxylated phosphate esters4 ; flame retardants, stain repellants, oxidizing bleaches, reducing bleaches, and plasticizers. Highly complex and unpredictable chemical cocktails in soils, groundwater and drinking water supplies cannot all be tested for, much less understood, or even fully quantified. These chemicals also mix and react with other natural and anthropogenic substances in soils, groundwater, public supply water and ecosystems. Complexity and cost of decontamination at a particular site is in general a function of time since release(s) occurred. As time goes on, soil contamination leads to groundwater contamination, with individual plumes commingling over broad areas, creating more and more complex contamination/decontamination environments and scenarios.
Perc enters the soil and thus groundwater and water supplies in three ways: airborne perc precipitates from the air in rain; perc leaks onsite and migrates downwards; and, perc‐bearing liquids are disposed of in drains and waste pipes ‐ many of which are unsealed or cracked. Perc is resilient and difficult to contain, seeping into the ground until it reaches rock or clay, which may be 40 feet or more below the surface. In some cases plumes spread over the course of decades, and have been known to spanned areas of up to 19 miles. Once it has entered groundwater, perc and its breakdown products are difficult to remove.
Perc is extremely pervasive and recalcitrant, concentrating in ecosystems and food chains. Even small amounts of perc in the water are toxic to aquatic animals, which store the chemical in their fatty tissues10. Some of these animals are human food sources. Perc shows up in: dairy products, meats, oils and fats, beverages, fruits and vegetables, fresh bread, fish, shellfish and marine mammals ‐ as well as rainwater, sea water, rivers, groundwater, commercial deionized charcoal‐filtered water11.
https://documents.geotracker.waterboards.ca.gov/regulators/deliverable_documents/72686287
76/Email%20Request%20‐ %20New%20Dry%20Cleaner%20Release%20Site%20(1600%20Capitola%20Road,%20Sant a%20Cruz)_04‐23‐2020.pdf
https://documents.geotracker.waterboards.ca.gov/regulators/deliverable_documents/72686287 76/EXAMPLE%20Explanatory%20letter%20from%20the%20Water%20Board%20(off‐ site%20responsibility).pdf
The Central Coast Water Board does not have direct authority to allow or deny development or land use change proposals for polluted properties; this authority resides with local land use permitting authorities. Therefore, for the Property:
- Central Coast Water Board staff won’t object to City Ventures’ Development proceeding while the responsible parties for the SVDC or City Ventures pursue ongoing cleanup actions to ensure protection of public health on the Property;
- Investigation, risk mitigation, and cleanup of pollutants not attributable to the SVDC site, are the responsibility of the current and past property owners and operators; and
- Development must not pose an unacceptable risk to human health and the environment in either a commercial or residential setting and may not exacerbate pollution conditions.
August 2020 letter to Chang, giving him the bad news ... "However, the responsible party (i.e. the property owners) are retired, without funds, and will need to obtain State grant monies, which may take a number of years to qualify."