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HomeMy WebLinkAbout2022-06-23; Encina Wastewater Authority Health Risk Assessment Update (District 3); Gomez, PazTo the members of the: CITY COUNCIL Date'-/13/:.u.CA ✓CC V CM ~ACM ~DCM (3) ~ June 23, 2022 To: From: Via: Council Memorandum embers of the City Council r, Public Works ~~~ {city of Carlsbad Memo ID #2022075 Re: Paz Gomez, Deputy Cit Scott Chadwick, City Encina Wastewater Health Risk Assessment Update (District 3) This memorandum provides an update to a previous Council Memorandum dated April 28, 2022, on the Encina Wastewater Authority's (EWA) required air quality health risk notifications that were sent to 18 Carlsbad residences and two businesses located near the Encina Water Pollution Control Facility (EWPCF) at 6200 Avenida Encinas. Background The April 28, 2022, Council Memorandum (Attachment A) provided background on the air quality health risk notifications that are required to be sent to 18 Carlsbad residences and two businesses located near the EWPCF, which treats Carlsbad wastewater. Per the requirements of Assembly Bill 2588, every four years, EWA must evaluate human health risk by applying various models to their emissions inventory against different types of exposure. Public notifications are required if health risk metrics are modeled above the public notification or risk reduction thresholds. As a result of EWA's Health Risk Assessment based on 2017 emissions data, some thresholds were exceeded. Discussion On June 13, 2022, the San Diego County Air Pollution Control District (APCD) sent letters to 18 Carlsbad residences regarding an elevated cancer risk due to EWPCF emissions and to two Carlsbad businesses regarding the exceedance of the acute health hazard index. These letters included notification of a virtual public meeting to be held on July 6, 2022. On June 15, 2022, EWA sent supplemental letters to the 18 residences and two businesses which explain the essential public infrastructure and the nature of wastewater operations along with the risk reduction strategies and a description of EWA's commitment to sustainability. Attachment B provides the standard APCD letters of June 13, 2022, which include a fact sheet on the APCD Air Toxics "Hot Spots" Program, and the standard EWA letters of June 15, 2022, that were sent to the affected residents and businesses. Attachment C contains maps with the public notification locations. Public Works Branch Utilities Department 5950 El Camino Real I Carlsbad, CA 92008 I 442-339-2722 t Council Memo -Encina Wastewater Authority Health Risk Assessment Update (District 3) June 23, 2022 Page 2 On the letters dated June 15, 2022, EWA described that they implement a capital improvement program and ongoing maintenance programs that replace and evaluate equipment to protect air quality and treat odors from the EWPCF. The EWA fiscal year 2022-23 budget includes a capital improvement project to begin evaluation of cogeneration system improvements to reduce emissions. Next Steps A virtual public meeting has been set for July 6, 2022, at 5 p.m., to discuss the information in the letters and address questions. The link to register for the virtual meeting is provided in the letters (Attachment B). City staff will continue to monitor the situation and provide updates to the City Council as needed. Attachments: A. Council Memorandum dated April 28, 2022 B. APCD letters dated June 13, 2022, and EWA letters dated June 15, 2022 C. Public notification locations cc: Geoff Patnoe, Assistant City Manager Celia Brewer, City Attorney Laura Rocha, Deputy City Manager, Administrative Services Robby Contreras, Assistant City Attorney David Graham, Chief Innovation Officer Vicki Quiram, Utilities Director James Wood, Environmental Management Director Kristina Ray, Communication & Engagement Director ATTACHMENT A To the members of the: 11 r1"f1 COUNCIL Date ~CA --.JL_CC ~ CM ~ACM ✓ DCM {3)L April 28, 2022 Council Memorandum To: Honorable Mayor Hall and Members of the City Council From: Paz Gomez, Deputy City Manager, Public Works Via: Geoff Patnoe, Assistant City Manager @ Re: Encina Wastewater Authority Health Risk Assessment (District 3) {city of Carlsbad Memo ID #2022049 This memorandum provides information related to Encina Wastewater Authority's (EWA) upcoming required air quality health risk notifications that will be sent to 18 Carlsbad residents and two businesses located near the Encina Water Pollution Control Facility (EWPCF). Background The San Diego County Air Pollution Control District (APCD) implements Assembly Bill (AB) 2588, which requires stationary sources of air pollution, such as the EWPCF located at 6200 Avenida Encinas, to report the types and quantities of certain substances routinely released into the air. This reporting is called a Health Risk Assessment and it is part of the Air Toxics "Hot Spots" Program. Attachment A contains a frequently asked questions flier on this program. EWA submits annual emissions inventory reports to the APCD, documenting various factors such as fuel consumption for heavy equipment on site. The most significant source of emissions is the cogeneration system, which converts wastewater gases to heat, providing nearly 85% of the plant's energy from a local and renewable source. Per the requirements of AB 2588, every four years, EWA must evaluate human health risk by applying various models to the emissions inventory against different types of exposure. After several years of correspondence, APCD recently finalized EWA's Health Risk Assessment based on 2017 emissions. Some health risk metrics were modeled above the public notification or risk reduction thresholds, and EWA is required to notify the public and reduce emissions. Discussion As a result of EWA's Health Risk Assessment, EWA must notify 18 residences of elevated cancer risk due to EWPCF emissions and two businesses of the exceedance of the acute health hazard index. These property owners will receive letters from the APCD notifying them of a virtual public meeting on a date to be determined in May or June 2022. EWA has also developed a supplemental letter, which will be included in the same mailer, to explain the essential public infrastructure and the nature of wastewater operations, along with risk reduction strategies and a description of EWA's commitment to sustainability. Attachment B Public Works Branch Utilities Department 5950 El Camino Real I Carlsbad, CA 92008 I 442-339-2722 t Council Memo -Encina Wastewater Authority Health Risk Assessment (District 3) April 28, 2022 Page 2 con~ains a standard APCD letter for residents and businesses, an EWA informational letter and a frequently asked questions flier. Attachment C contains maps with the addresses of the 18 residents and two businesses that will be notified of this assessment. The next Health Risk Assessment will be based on the 2021 emissions inventory, which is currently under review and expected to be published by 2023. Air quality regulations are becoming more stringent in the San Diego area, as APCD has approved reclassification of the San Diego region from "Serious" to "Severe" for ozone nonattainment. Many wastewater treatment facilities in the Los Angeles area and Orange County are held to these stricter emissions standards. Next Steps EWA will send notification letters to 18 residences and two businesses, including an invitation to a public meeting, in the coming weeks. City staff will continue to monitor the situation and provide updates to the City Council as needed. The EWA fiscal year 2022-23 budget includes a capital improvement project to begin evaluation of cogeneration system improvements to reduce emissions. Attachments: A. APCD Air Toxics "Hot Spots" Program fact sheet B. APCD standard notification letter template C. Public notification locations cc: Scott Chadwick, City Manager Celia Brewer, City Attorney Robby Contreras, Assistant City Attorney Vicki Quiram, Utilities Director James Wood, Environmental Management Director Kristina Ray, Communication & EngagementDirector 10124 Old Grove Rd. San Diego California 92131-1649 (858) 586-2600 Fax (858) 586-2601 www.sdapcd.org Air Toxics "Hot Spots" Program Fact Sheet What is the Air Toxics "Hot Spots" Program? The California Air Toxics “Hot Spots” Information and Assessment Act (Hot Spots Act), Assembly Bill 2588, was adopted into State Law in 1987 to address public health risks from toxic air contaminants emitted by stationary sources (including manufacturing operations, power plants, and other industrial, commercial and governmental operations). The Hot Spots Act requires local air pollution control districts to evaluate toxic air contaminant emissions from various stationary sources and determine which sources generate emissions that may present public health concerns. It also requires stationary source operators to notify communities and develop and implement strategies to reduce their potential health risks when those health risks are above specified levels. The San Diego County Air Pollution Control District (APCD) is responsible for implementing the Air Toxics “Hot Spots” Program (Program) in San Diego County by: (1) evaluating emissions of toxic air contaminants from stationary sources; (2) identifying sources that can create elevated health risks; and, (3) implementing public notification and risk reduction requirements through APCD Rule 1210, whichestablishes public notification and risk reduction thresholds and procedures1. What is a toxic air contaminant? Toxic air contaminants are chemicals in gases, liquids, or particles form which are emitted into the atmosphere that upon inhalation, digestion or skin contact may cause adverse health effects. Adverse health effects can range from relatively mild temporary conditions, such as minor eye or throat irritation, shortness of breath or headaches, to permanent and serious conditions such as cancer, birth defects, or damage to lungs, nerves, the liver, the heart, or other organs. The nature and severity of health effects vary by the type and quantity of pollutant, the duration of exposure, the distance from the emission source and the sensitivity of the individual. An example of a toxic air contaminant is diesel particulate matter (diesel PM), which is emitted from diesel engines2. The toxic air contaminants evaluated under this Program are included in the tables at the end of APCD Rule 12101. What is a health risk assessment? A health risk assessment estimates the risk of adverse health effects (cancer and noncancer) from exposures to emissions of toxic air contaminants into the air3. The estimated health risks are based on APCD approved emission calculations, state approved computer models, and health risk calculations based on a number of assumptions, some of which are health protective. 1 Rule 1210-Toxic Air Contaminant Health Risks-Public Notification and Risk Reduction (11/04/2021) (sdapcd.org) 2 https://oehha.ca.gov/calenviroscreen/indicator/diesel-particulate-matter 3 Guide to Health Risk Assessment (ca.gov) ATTACHMENT A /~· San Diego County -.~ Air Pollution .,,, Control District In accordance with state law (California Health and Safety Code, Section 44362), health risk assessments are to be conducted by operators of stationary sources, within 180 days from a APCD request, and approved by the APCD, in consultation with the California state Office of Environmental Health Hazard Assessment (OEHHA) within one year from the submittal of the Health Risk Assessment. OEHHA is the scientific branch of the California Environmental Protection Agency (CalEPA) which evaluates the effects of toxic compounds and develops health protective exposure levels and health risk assessment guidelines4. How accurate is the health risk assessment? The OEHHA guidelines states5 “OEHHA has striven to use the best science available in developing these risk assessment guidelines. However, there is a great deal of uncertainty associated with the process of risk assessment. The uncertainty arises from lack of data in many areas necessitating the use of assumptions. The assumptions used in these guidelines are designed to err on the side of health protection in order to avoid underestimation of risk to the public. Sources of uncertainty, which may overestimate or underestimate risk, include: 1) extrapolation of toxicity data in animals to humans, 2) uncertainty in the estimation of emissions, 3) uncertainty in the air dispersion models, and 4) uncertainty in the exposure estimates.”. Additional information is available at https://oehha.ca.gov/media/downloads/risk-assessment/document/hrsguide2001.pdf How are risk assessment results reported? Risk assessment results are reported as "excess lifetime cancer risk" and/or as "non-cancer hazard index." • Excess lifetime cancer risk is the maximum estimated increased risk of contracting cancer (above normal background levels) caused by chronic exposure to a chemical suspected of being a human or animal carcinogen. Excess lifetime cancer risk is expressed as the probability of a resident or worker contracting cancer. This estimate assumes that a person resides at the location of maximum residential impact 24 hours per day, 365 days per year with 30 years of exposure, or a person works at the location of maximum occupational impact 8 hours per day, 250 days per year, with 25 years of exposure. To help put these risks into perspective, in accordance with the California Environmental Protection Agency, “cancer risks presented in risk assessments are often compared to the overall risk of cancer in the general U.S. population (about 250,000 cases for every one million people) or to the risk posed by all harmful chemicals in a particular medium, such as the air. The cancer risk from breathing current levels of pollutants in California’s ambient air over a 70-year lifetime is estimated to be 760 in one million”6 • Non-cancer health hazard index is calculated by dividing the estimated level of exposure to chemicals emitted from a facility to the level of exposure that is not expected to cause any adverse health effects. If the hazard index is less than or equal to one, then the estimated level of exposure is not likely to result in adverse health effects for anyone, including sensitive individuals such as children and the elderly. A hazard index above one indicates that there may be greater potential 4 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf 5 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf, page 1-5 6 Guide to Health Risk Assessment (ca.gov), page 10 for adverse health impacts from exposure to the toxic air contaminants of concern7. Under the Hot Spots program, a hazard index is calculated for both acute (short-term) and chronic (long-term) exposures to air toxic contaminants in facility emissions. • Cancer burden estimates the number of potential excess cancer cases within the population that would be exposed to the emissions for a lifetime (70 years). The cancer burden is calculated on the basis of lifetime (70-year) risks (whereas individual cancer risk is based on 30-year residential exposure).8 What is being done to reduce toxic air contaminant emissions? On November 4, 2021, the APCD Governing Board approved amendments to Rule 1210 which reduced the cancer risk threshold for risk reductions from 100 in one million to 10 in one million for emissions that occurred in 2018 and later years, consistent with the cancer risk threshold for public notifications. For more information regarding the Hot Spots Program please visit the APCD website at https://bit.ly/31XQXd69 7 February 2015, Air Toxics Hot Spots Program Risk Assessment (ca.gov) 8 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf 9https://www.sdapcd.org/content/sdc/apcd/en/engineering/Permits/Engineering_Emissions_Inventory/engineering_phase2hotspots.html 10124 Old Grove Rd. San Diego California 92131-1649 (858) 586-2600 Fax (858) 586-2601 www.sdapcd.org Date Dear Employee: State law (Air Toxics "Hot Spots" Information and Assessment Act of 1987) protects your right to know about possible health risks from toxic air contaminants emitted by sources of air pollution in your neighborhood. The San Diego County Air Pollution Control District (APCD) is the local government agency responsible for implementing the Air Toxics “Hot Spots” Program in San Diego County. The following facility is required to notify all community members and workers living and/or working in areas where there is a potential health risk at or above the significant risk threshold in accordance with APCD Rule 1210. The enclosed potential acute health hazard map shows the boundaries of the area that is exposed to health risks at or above the significant risk threshold. Facility Name: Encina Wastewater Authority Address: 6200 Avenida Encinas, Carlsbad, CA 92009 Type of Business: Municipal Wastewater Treatment Based on air emission data in 2017 the APCD requested a health risk assessment from Encina Wastewater Authority. The health risk assessment, approved by the APCD in March of 2022, shows that the level of exposure to some toxic air contaminants, primarily Formaldehyde and Sodium Hydroxide, may result in greater potential for adverse health impacts. Specifically, the Health Risk Assessment shows the Maximum Occupational Acute Health Hazard Index is 1.06. The noncancer health hazard index is calculated by dividing the estimated level of exposure to chemicals emitted from a facility to the level of exposure that is not expected to cause any adverse health effects. If the hazard index is less than or equal to one, then the estimated level of exposure is not likely to result in adverse health effects for anyone, including sensitive individuals such as children and the elderly. A hazard index above one indicates that there may be greater potential for adverse health impacts from exposure to the toxic air contaminants of concern. A hazard index is calculated for both acute (short-term) and chronic (long-term) exposures to air toxic contaminants in facility emissions. APCD Rule 1210 requires public notification when any of the non-cancer health hazard indexes are greater than 1.0, and also requires facilities with predicted risks above these health risk thresholds to reduce their health risks below these thresholds. The APCD has prepared the enclosed “Program Fact Sheet” regarding its Air Toxic Hot Spots Program and a survey card to obtain your questions and comments regarding the information provided in this notice. If you would like more information, please complete and return the ATTACHMENT B /~· San Diego County _.Jiilll Air Pollution ~ Control District - enclosed survey card to the APCD via mail, 10124 Old Grove Road, San Diego, 92131, or e-mail at APCDEngineering@sdapcd.org. Additionally, a virtual public meeting has been scheduled for PUBLIC MEETING DETALS to discuss the information on this notification and address your questions. For more information regarding the APCD’s Air Toxics Hot Spots program, please contact the APCD at 858-586-2600 or via email at APCDEngineering@sdapcd.org. For more information regarding the facility please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com with Encina Wastewater Authority. Sincerely, PAULA FORBIS Air Pollution Control Officer ENCINA WASTEWATER AUTHORITY . . A Public Agency SERVING THE CITY OF VISTA, CITY OF CARLSBAD, BUENA SANITATION DISTRICT, VALLECITOS WATER DISTRICT, LEUCADIA WASTEWATER DISTRICT AND CITY OF ENCINITAS 6200 Avenida Encinas Carlsbad, CA 92011-1095 Telephone (760) 438-3941 FAX (760) 438-3861 (Plant) (760) 431-7493 (Admin) April 18, 2022 Dear Business Owner: Encina Wastewater Authority (Encina) is required by the San Diego County Air Pollution Control District (SDAPCD) to conduct periodic heath risk assessments that evaluate air pollutants released from the Encina Water Pollution Control Facility located at 6200 Avenida Encinas. You are receiving this letter because your business is within an area predicted to have an acute health risk slightly above the public notification threshold as a result of the 2017 facility operations. This letter describes the nature and context of the potential impacts to help you evaluate the information in this required public notification. Health Risk Assessment Health risk assessments provide a theoretical estimate of the chance that a person may experience a health effect from exposure to chemicals based on predictive computer modeling. While any emission of toxic air pollutants is a concern to Encina, the estimated risk discussed in this notice is based on a worst-case scenario of 1-hour exposure to emissions from all sources at the facility operating simultaneously, even though all sources do not operate simultaneously. The health risk assessment used regulatory models that are designed to ensure impacts are not underestimated, for example the toxicity factors include safety and uncertainty factors to adjust the data from animal studies to humans. Risk assessments cannot predict actual health risks or be used to determine if a particular health issue was caused by a chemical. Instead, they are used to support regulatory activities by comparing results to various threshold levels considered protective of human health. Results of Health Risk Assessment The risk assessment conducted by the SDAPCD indicated that two businesses may experience short-term, non-cancer health impacts due to Encina operations. The public notification thresholds are set at a level designed to protect the most sensitive individuals in the population. If an acute risk is predicted to be greater than 1, this means there is a potential for a short-term (1-hour) health impact. The modeling predicted the maximum occupational acute risk to be 1.06, just over the notification threshold. The SDAPCD used maximum hourly emission rates from all sources in the analysis, even though all sources do not operate simultaneously or continuously. Importantly, only three of the four cogeneration engines ever operate simultaneously. Thus, modeling all four engines, plus the emergency generators, in use for 1 hour overestimated the associated health risks. The SDAPCD model included emissions of sodium hydroxide and chlorine from the Odor Reduction System #3 associated with the aerated sludge system by default. These substances were no longer used in the pollution control scrubber in 2017. Therefore, emissions and associated health risks were overestimated. To put these results in perspective, the toxicity factors for the top three chemicals are between 7 and 250 times more health protective than CalOSHA permissible exposure limits. Emission Reduction Measures As part of this Health Risk Assessment, Encina is required to submit a risk reduction plan to the SDAPCD in August 2022. Encina has already eliminated one source of emissions accounted for in the HRA models: at Odor Reduction System #3, Encina discontinued use of sodium hydroxide and chlorine in 2016. The SDAPCD permit was modified in 2016 and again in 2019 to reflect the removal of the caustic scrubber and the use of these chemicals. Without the inclusion of these chemicals from this source, the acute risk drops below the SDAPCD threshold. In addition, Encina implements a Capital Improvement Program and ongoing maintenance programs that replace and evaluate equipment to protect air quality and treat odors from the Water Pollution Control Facility. About Encina Wastewater Authority Encina provides essential public services treating up to 43 million gallons per day of wastewater from over 379,000 residents and businesses throughout a 125-square-mile service area. Encina is owned by six public agencies and governed by a Joint Powers Authority that includes the Cities of Carlsbad, Vista, and Encinitas as well as Buena Sanitation, Vallecitos Water, and Leucadia Wastewater Districts. The Facility houses complex processes and equipment that protects the local ocean environment, preserves public health, and provides valuable water resources for the region. It also has extensive systems for process odor control, electricity generation from treatment process gas (cogeneration), and biosolids processing that produces a high-quality fertilizer product that is beneficially used. More Information If you would like further information about Encina’s facility, please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com. Sincerely, Alicia Appel Director of Environmental Compliance Encina Wastewater Authority ENCINA WASTEWATER AUTHORITY . . A Public Agency SERVING THE CITY OF VISTA, CITY OF CARLSBAD, BUENA SANITATION DISTRICT, VALLECITOS WATER DISTRICT, LEUCADIA WASTEWATER DISTRICT AND CITY OF ENCINITAS 6200 Avenida Encinas Carlsbad, CA 92011-1095 Telephone (760) 438-3941 FAX (760) 438-3861 (Plant) (760) 431-7493 (Admin) April 18, 2022 Dear Business Owner: Encina Wastewater Authority (EWA) is providing this letter to supplement the information provided by the San Diego County Air Pollution Control District (SDAPCD) regarding the recently conducted Health Risk Assessment based on 2017 operations of the Encina Water Pollution Control Facility located at 6200 Avenida Encinas in Carlsbad. Per the Air Toxics "Hot Spots" Information and Assessment Act of 1987, you are required to post or provide to each onsite employee a copy of the SDAPCD public notification letter. The SDAPCD letter can be posted onsite, mailed, or emailed to each employee that works onsite. For more information regarding the SDAPCD’s Air Toxics Hot Spots program, please contact the SDAPCD at 858-586-2600 or via email at APCDEngineering@sdapcd.org. For more information regarding the facility please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com with Encina Wastewater Authority. Sincerely, Alicia Appel Encina Wastewater Authority 10124 Old Grove Rd. San Diego California 92131-1649 (858) 586-2600 Fax (858) 586-2601 www.sdapcd.org Date Dear Community Member: State law (Air Toxics "Hot Spots" Information and Assessment Act of 1987) protects your right to know about possible health risks from toxic air contaminants emitted by sources of air pollution in your neighborhood. The San Diego County Air Pollution Control District (APCD) is the local government agency responsible for implementing the Air Toxics “Hot Spots” Program in San Diego County. The following facility is required to notify all community members and workers living and/or working in areas where there is a potential health risk at or above the significant risk threshold in accordance with APCD Rule 1210. The enclosed potential cancer risk map shows the boundaries of the area that is exposed to health risks at or above the significant risk threshold. Facility Name: Encina Wastewater Authority Address: 6200 Avenida Encinas, Carlsbad, CA 92009 Type of Business: Municipal Wastewater Treatment Based on air emission data in 2017 the APCD requested a health risk assessment from Encina Wastewater Authority. The health risk assessment, approved by the APCD in March of 2022, shows that some toxic air contaminants, primarily formaldehyde and polycyclic aromatic hydrocarbons (PAHs), from Encina Wastewater Authority may be increasing the cancer risks for people who live in the area to a maximum increase of 13.42 chances in one million of getting cancer. APCD Rule 1210 requires public notification when the cancer risk is above 10 in one million. APCD Rule 1210 also requires facilities with emissions from 2017 and associated predicted cancer risk above the reduction threshold of 100 in one million to reduce their health risks below these thresholds. The APCD has prepared the enclosed “Program Fact Sheet” regarding its Air Toxic Hot Spots Program and a survey card to obtain your questions and comments regarding the information provided in this notice. If you would like more information, please complete and return the enclosed survey card to the APCD via mail, 10124 Old Grove Road, San Diego, 92131, or e-mail at APCDEngineering@sdapcd.org. Additionally, a virtual public meeting has been scheduled for PUBLIC MEETING DETALS to discuss the information on this notification and address your questions. For more information regarding the APCD’s Air Toxics Hot Spots program, please contact the APCD at 858-586-2600 /~· San Diego County _.Jiilll Air Pollution ~ Control District - or via email at APCDEngineering@sdapcd.org. For more information regarding the facility please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com with Encina Wastewater Authority. Sincerely, PAULA FORBIS Air Pollution Control Officer ENCINA WASTEWATER AUTHORITY . . A Public Agency SERVING THE CITY OF VISTA, CITY OF CARLSBAD, BUENA SANITATION DISTRICT, VALLECITOS WATER DISTRICT, LEUCADIA WASTEWATER DISTRICT AND CITY OF ENCINITAS 6200 Avenida Encinas Carlsbad, CA 92011-1095 Telephone (760) 438-3941 FAX (760) 438-3861 (Plant) (760) 431-7493 (Admin) April 18, 2022 Dear Resident: Encina Wastewater Authority (Encina) is required by the San Diego County Air Pollution Control District (SDAPCD) to conduct periodic heath risk assessments that evaluate air pollutants released from the Encina Water Pollution Control Facility located at 6200 Avenida Encinas. You are receiving this letter because you live within an area predicted to have a chance of excess cancer risk slightly above the public notification threshold as a result of the 2017 facility operations. This letter describes the nature and context of the potential impacts to help you evaluate the information in this required public notification. Health Risk Assessment Health risk assessments provide a theoretical estimate of the chance that a person may experience a health effect from exposure to chemicals based on predictive computer modeling. While any emission of toxic air pollutants is a concern to Encina, the estimated risk discussed in this notice is based on a hypothetical person who resides in one location 24 hours a day, for 30 years, and is exposed to 2017 facility emission levels. The health risk assessment used regulatory models that are designed to ensure impacts are not underestimated, for example the toxicity factors include safety and uncertainty factors to adjust the data from animal studies to humans. Risk assessments cannot predict actual health risks or be used to determine if a particular health issue was caused by a chemical. Instead, they are used to support regulatory activities by comparing results to various threshold levels considered protective of human health. Results of Health Risk Assessment The risk assessment conducted by the SDAPCD indicated that 14 residences may experience an excess cancer risk slightly greater than 10 in one million, up to 13.42 in a million due to Encina’s wastewater operations. Cancer risk is the probability that a person might contract cancer if exposed to toxic chemical emissions from remaining at their property continuously for 30 years. A cancer risk of 1 in one million means that in a population of one million people, not more than one additional person would have the chance of developing cancer as the result of the exposure to the toxic air pollutant. To put this in perspective, the average Californian has a 720 in one million chance of getting cancer due to the toxics in the ambient air, with the majority from diesel particulate matter emissions, and there is an approximately 400,000 in one million chance due to all causes. Emission Reduction Measures The health risks from Encina’s emissions are not significant enough for the District to require risk reduction measures. Encina controls emissions by implementing a Capital Improvement Program and ongoing maintenance programs that evaluate, upgrade, and replace equipment to protect air quality and treat odors from the Facility. About Encina Wastewater Authority Encina provides essential public services treating up to 43 million gallons per day of wastewater from over 379,000 residents and businesses throughout a 125-square-mile service area. Encina is owned by six public agencies and governed by a Joint Powers Authority that includes the Cities of Carlsbad, Vista, and Encinitas as well as Buena Sanitation, Vallecitos Water, and Leucadia Wastewater Districts. The Facility houses complex processes and equipment that protects the local ocean environment, preserves public health, and provides valuable water resources for the region. It also has extensive systems for process odor control, electricity generation from treatment process gas (cogeneration), and biosolids processing that produces a high-quality fertilizer product that is beneficially used. More Information If you would like further information about Encina’s facility, please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com. Sincerely, Alicia Appel Director of Environmental Compliance Encina Wastewater Authority 10124 Old Grove Rd. San Diego California 92131-1649 (858) 586-2600 Fax (858) 586-2601 www.sdapcd.org Air Toxics "Hot Spots" Program Fact Sheet What is the Air Toxics "Hot Spots" Program? The California Air Toxics “Hot Spots” Information and Assessment Act (Hot Spots Act), Assembly Bill 2588, was adopted into State Law in 1987 to address public health risks from toxic air contaminants emitted by stationary sources (including manufacturing operations, power plants, and other industrial, commercial and governmental operations). The Hot Spots Act requires local air pollution control districts to evaluate toxic air contaminant emissions from various stationary sources and determine which sources generate emissions that may present public health concerns. It also requires stationary source operators to notify communities and develop and implement strategies to reduce their potential health risks when those health risks are above specified levels. The San Diego County Air Pollution Control District (APCD) is responsible for implementing the Air Toxics “Hot Spots” Program (Program) in San Diego County by: (1) evaluating emissions of toxic air contaminants from stationary sources; (2) identifying sources that can create elevated health risks; and, (3) implementing public notification and risk reduction requirements through APCD Rule 1210, which establishes public notification and risk reduction thresholds and procedures1. What is a toxic air contaminant? Toxic air contaminants are chemicals in gases, liquids, or particles form which are emitted into the atmosphere that upon inhalation, digestion or skin contact may cause adverse health effects. Adverse health effects can range from relatively mild temporary conditions, such as minor eye or throat irritation, shortness of breath or headaches, to permanent and serious conditions such as cancer, birth defects, or damage to lungs, nerves, the liver, the heart, or other organs. The nature and severity of health effects vary by the type and quantity of pollutant, the duration of exposure, the distance from the emission source and the sensitivity of the individual. An example of a toxic air contaminant is diesel particulate matter (diesel PM), which is emitted from diesel engines2. The toxic air contaminants evaluated under this Program are included in the tables at the end of APCD Rule 12101. What is a health risk assessment? A health risk assessment estimates the risk of adverse health effects (cancer and noncancer) from exposures to emissions of toxic air contaminants into the air3. The estimated health risks are based on APCD approved emission calculations, state approved computer models, and health risk calculations based on a number of assumptions, some of which are health protective. 1 Rule 1210-Toxic Air Contaminant Health Risks-Public Notification and Risk Reduction (11/04/2021) (sdapcd.org) 2 https://oehha.ca.gov/calenviroscreen/indicator/diesel-particulate-matter 3 Guide to Health Risk Assessment (ca.gov) /~· San Diego County -.~ Air Pollution .,,, Control District In accordance with state law (California Health and Safety Code, Section 44362), health risk assessments are to be conducted by operators of stationary sources, within 180 days from a APCD request, and approved by the APCD, in consultation with the California state Office of Environmental Health Hazard Assessment (OEHHA) within one year from the submittal of the Health Risk Assessment. OEHHA is the scientific branch of the California Environmental Protection Agency (CalEPA) which evaluates the effects of toxic compounds and develops health protective exposure levels and health risk assessment guidelines4. How accurate is the health risk assessment? The OEHHA guidelines states5 “OEHHA has striven to use the best science available in developing these risk assessment guidelines. However, there is a great deal of uncertainty associated with the process of risk assessment. The uncertainty arises from lack of data in many areas necessitating the use of assumptions. The assumptions used in these guidelines are designed to err on the side of health protection in order to avoid underestimation of risk to the public. Sources of uncertainty, which may overestimate or underestimate risk, include: 1) extrapolation of toxicity data in animals to humans, 2) uncertainty in the estimation of emissions, 3) uncertainty in the air dispersion models, and 4) uncertainty in the exposure estimates.”. Additional information is available at https://oehha.ca.gov/media/downloads/risk-assessment/document/hrsguide2001.pdf How are risk assessment results reported? Risk assessment results are reported as "excess lifetime cancer risk" and/or as "non-cancer hazard index." • Excess lifetime cancer risk is the maximum estimated increased risk of contracting cancer (above normal background levels) caused by chronic exposure to a chemical suspected of being a human or animal carcinogen. Excess lifetime cancer risk is expressed as the probability of a resident or worker contracting cancer. This estimate assumes that a person resides at the location of maximum residential impact 24 hours per day, 365 days per year with 30 years of exposure, or a person works at the location of maximum occupational impact 8 hours per day, 250 days per year, with 25 years of exposure. To help put these risks into perspective, in accordance with the California Environmental Protection Agency, “cancer risks presented in risk assessments are often compared to the overall risk of cancer in the general U.S. population (about 250,000 cases for every one million people) or to the risk posed by all harmful chemicals in a particular medium, such as the air. The cancer risk from breathing current levels of pollutants in California’s ambient air over a 70-year lifetime is estimated to be 760 in one million”6 • Non-cancer health hazard index is calculated by dividing the estimated level of exposure to chemicals emitted from a facility to the level of exposure that is not expected to cause any adverse health effects. If the hazard index is less than or equal to one, then the estimated level of exposure is not likely to result in adverse health effects for anyone, including sensitive individuals such as children and the elderly. A hazard index above one indicates that there may be greater potential 4 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf 5 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf, page 1-5 6 Guide to Health Risk Assessment (ca.gov), page 10 for adverse health impacts from exposure to the toxic air contaminants of concern7. Under the Hot Spots program, a hazard index is calculated for both acute (short-term) and chronic (long-term) exposures to air toxic contaminants in facility emissions. • Cancer burden estimates the number of potential excess cancer cases within the population that would be exposed to the emissions for a lifetime (70 years). The cancer burden is calculated on the basis of lifetime (70-year) risks (whereas individual cancer risk is based on 30-year residential exposure).8 What is being done to reduce toxic air contaminant emissions? On November 4, 2021, the APCD Governing Board approved amendments to Rule 1210 which reduced the cancer risk threshold for risk reductions from 100 in one million to 10 in one million for emissions that occurred in 2018 and later years, consistent with the cancer risk threshold for public notifications. For more information regarding the Hot Spots Program please visit the APCD website at https://bit.ly/31XQXd69 7 February 2015, Air Toxics Hot Spots Program Risk Assessment (ca.gov) 8 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf 9https://www.sdapcd.org/content/sdc/apcd/en/engineering/Permits/Engineering_Emissions_Inventory/engineering_phase2hotspots.html ATTACHMENT C Encina Wastewater Authority AB 2588 Health Risk Assessment for Reporting Year 2017 Public Notification Locations ACUTE RECPTORS Receptors with Acute Hazard Indices Greater than Notification Threshold Receptor Number UTM Easting (m) UTM Northing (m) Acute Hazard Index Name Address 95 470,355 3,664,224 1.061 U-Haul Moving & Storage of Carlsbad 6175 Paseo Del Norte, Carlsbad, CA 92011 97 470,364 3,664,207 1.052 94 470,344 3,664,244 1.045 96 470,368 3,664,212 1.004 874 470,029 3,664,379 1.009 Ewing Irrigation & Landscape Supply 6104 Avenida Encinas, Carlsbad, CA 92011 ATTACHMENT C Figure 1: Locations of Receptors with Acute Risk > Public Notification Threshold 469900 469950 470000 Ewing Irrigation & La dscap 6104 Avenida Encinas 470050 470100 470150 470200 UTM East [m] 470250 470300 470350 470400 470450 470500 ATTACHMENT C CANCER RECPTORS Receptors with Cancer Risk Greater than Notification Threshold Receptor Number UTM Easting (m) UTM Northing (m) Cancer Risk (in a million) Name Address 58 470,494 3,664,296 13.415 Seagate Condominium Complex 956 & 958 Tide Ct, Carlsbad, CA 92011 85 470,499 3,664,302 13.232 Seagate Condominium Complex 950 & 954 Tide Ct, Carlsbad, CA 92011 86 470,505 3,664,311 12.957 Seagate Condominium Complex 944 & 952 Tide Ct, Carlsbad, CA 92011 87 470,514 3,664,322 12.412 Seagate Condominium Complex 946 & 948 Tide Ct, Carlsbad, CA 92011 88 470,521 3,664,330 12.012 Seagate Condominium Complex 940 & 942 Tide Ct, Carlsbad, CA 92011 57 470,515 3,664,276 11.943 Seagate Condominium Complex In the neighborhood but not on a structure 1209 470,529 3,664,279 11.414 Seagate Condominium Complex In the neighborhood but not on a structure 1210 470,529 3,664,329 11.634 Seagate Condominium Complex In the neighborhood but not on a structure There are no receptors at the following addresses, but they fall within the 10 in a million isopleth Seagate Condominium Complex 932, 934, 936 & 938 Tide Ct, Carlsbad, CA 92011 Receptors with Cancer Risk LESS THAN Notification Threshold Receptor Number UTM Easting (m) UTM Northing (m) Cancer Risk (in a million) Name Address 1251 470,579 3,664,329 9.707 Seagate Condominium Complex 922, 924, 926 & 928 Tide Ct ATTACHMENT C Figure 2: Locations of Receptors with Cancer Risk > Public Notification Threshold 470490 470500 470510 470520 470530 470540 470550 470560 470570 470580 470590 470600 470610 470620 470630 470640 UTM East [m] 10124 Old Grove Rd. San Diego California 92131-1649 (858) 586-2600 Fax (858) 586-2601 www.sdapcd.org Air Toxics "Hot Spots" Program Fact Sheet What is the Air Toxics "Hot Spots" Program? The California Air Toxics “Hot Spots” Information and Assessment Act (Hot Spots Act), Assembly Bill 2588, was adopted into State Law in 1987 to address public health risks from toxic air contaminants emitted by stationary sources (including manufacturing operations, power plants, and other industrial, commercial and governmental operations). The Hot Spots Act requires local air pollution control districts to evaluate toxic air contaminant emissions from various stationary sources and determine which sources generate emissions that may present public health concerns. It also requires stationary source operators to notify communities and develop and implement strategies to reduce their potential health risks when those health risks are above specified levels. The San Diego County Air Pollution Control District (APCD) is responsible for implementing the Air Toxics “Hot Spots” Program (Program) in San Diego County by: (1) evaluating emissions of toxic air contaminants from stationary sources; (2) identifying sources that can create elevated health risks; and, (3) implementing public notification and risk reduction requirements through APCD Rule 1210, whichestablishes public notification and risk reduction thresholds and procedures1. What is a toxic air contaminant? Toxic air contaminants are chemicals in gases, liquids, or particles form which are emitted into the atmosphere that upon inhalation, digestion or skin contact may cause adverse health effects. Adverse health effects can range from relatively mild temporary conditions, such as minor eye or throat irritation, shortness of breath or headaches, to permanent and serious conditions such as cancer, birth defects, or damage to lungs, nerves, the liver, the heart, or other organs. The nature and severity of health effects vary by the type and quantity of pollutant, the duration of exposure, the distance from the emission source and the sensitivity of the individual. An example of a toxic air contaminant is diesel particulate matter (diesel PM), which is emitted from diesel engines2. The toxic air contaminants evaluated under this Program are included in the tables at the end of APCD Rule 12101. What is a health risk assessment? A health risk assessment estimates the risk of adverse health effects (cancer and noncancer) from exposures to emissions of toxic air contaminants into the air3. The estimated health risks are based on APCD approved emission calculations, state approved computer models, and health risk calculations based on a number of assumptions, some of which are health protective. 1 Rule 1210-Toxic Air Contaminant Health Risks-Public Notification and Risk Reduction (11/04/2021) (sdapcd.org) 2 https://oehha.ca.gov/calenviroscreen/indicator/diesel-particulate-matter 3 Guide to Health Risk Assessment (ca.gov) ATTACHMENT B /~· San Diego County -.~ Air Pollution .,,, Control District In accordance with state law (California Health and Safety Code, Section 44362), health risk assessments are to be conducted by operators of stationary sources, within 180 days from a APCD request, and approved by the APCD, in consultation with the California state Office of Environmental Health Hazard Assessment (OEHHA) within one year from the submittal of the Health Risk Assessment. OEHHA is the scientific branch of the California Environmental Protection Agency (CalEPA) which evaluates the effects of toxic compounds and develops health protective exposure levels and health risk assessment guidelines4. How accurate is the health risk assessment? The OEHHA guidelines states5 “OEHHA has striven to use the best science available in developing these risk assessment guidelines. However, there is a great deal of uncertainty associated with the process of risk assessment. The uncertainty arises from lack of data in many areas necessitating the use of assumptions. The assumptions used in these guidelines are designed to err on the side of health protection in order to avoid underestimation of risk to the public. Sources of uncertainty, which may overestimate or underestimate risk, include: 1) extrapolation of toxicity data in animals to humans, 2) uncertainty in the estimation of emissions, 3) uncertainty in the air dispersion models, and 4) uncertainty in the exposure estimates.”. Additional information is available at https://oehha.ca.gov/media/downloads/risk-assessment/document/hrsguide2001.pdf How are risk assessment results reported? Risk assessment results are reported as "excess lifetime cancer risk" and/or as "non-cancer hazard index." •Excess lifetime cancer risk is the maximum estimated increased risk of contracting cancer(above normal background levels) caused by chronic exposure to a chemical suspected of beinga human or animal carcinogen. Excess lifetime cancer risk is expressed as the probability of aresident or worker contracting cancer. This estimate assumes that a person resides at the locationof maximum residential impact 24 hours per day, 365 days per year with 30 years of exposure, or a person works at the location of maximum occupational impact 8 hours per day, 250 days peryear, with 25 years of exposure. To help put these risks into perspective, in accordance with the California EnvironmentalProtection Agency, “cancer risks presented in risk assessments are often compared to the overall risk of cancer in the general U.S. population (about 250,000 cases for every one million people) or to the risk posed by all harmful chemicals in a particular medium, such as the air.The cancer risk from breathing current levels of pollutants in California’s ambient air over a70-year lifetime is estimated to be 760 in one million”6 •Non-cancer health hazard index is calculated by dividing the estimated level of exposure tochemicals emitted from a facility to the level of exposure that is not expected to cause any adversehealth effects. If the hazard index is less than or equal to one, then the estimated level of exposureis not likely to result in adverse health effects for anyone, including sensitive individuals such as children and the elderly. A hazard index above one indicates that there may be greater potential 4 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf 5 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf, page 1-5 6 Guide to Health Risk Assessment (ca.gov), page 10 for adverse health impacts from exposure to the toxic air contaminants of concern7. Under the Hot Spots program, a hazard index is calculated for both acute (short-term) and chronic (long-term) exposures to air toxic contaminants in facility emissions. •Cancer burden estimates the number of potential excess cancer cases within the population that would be exposed to the emissions for a lifetime (70 years). The cancer burden is calculated onthe basis of lifetime (70-year) risks (whereas individual cancer risk is based on 30-year residentialexposure).8 What is being done to reduce toxic air contaminant emissions? On November 4, 2021, the APCD Governing Board approved amendments to Rule 1210 which reduced the cancer risk threshold for risk reductions from 100 in one million to 10 in one million for emissions that occurred in 2018 and later years, consistent with the cancer risk threshold for public notifications. For more information regarding the Hot Spots Program please visit the APCD website at https://bit.ly/31XQXd69 7 February 2015, Air Toxics Hot Spots Program Risk Assessment (ca.gov) 8 https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf 9https://www.sdapcd.org/content/sdc/apcd/en/engineering/Permits/Engineering_Emissions_Inventory/engineering_phase2hotspots.html 10124 Old Grove Rd. San Diego California 92131-1649 (858) 586-2600 Fax (858) 586-2601 www.sdapcd.org June 13, 2022 Dear Community Member: State law (Air Toxics "Hot Spots" Information and Assessment Act of 1987) protects your right to know about possible health risks from toxic air contaminants emitted by sources of air pollution in your neighborhood. The San Diego County Air Pollution Control District (APCD) is the local government agency responsible for implementing the Air Toxics “Hot Spots” Program in San Diego County. The following facility is required to notify all community members in areas where there is a potential health risk at or above the significant risk threshold in accordance with APCD Rule 1210 and hold a public meeting to discuss this information. The enclosed map shows the boundaries of the area that is exposed to health risks at or above the significant risk threshold. Facility Name: Encina Wastewater Authority Address: 6200 Avenida Encinas, Carlsbad, CA 92009 Type of Business: Municipal Wastewater Treatment Based on air emission data in 2017 the APCD requested a health risk assessment from Encina Wastewater Authority. The health risk assessment, approved by the APCD on March 3, 2022, shows that some toxic air contaminants, primarily formaldehyde resulting from the operation of cogeneration engines, from Encina Wastewater Authority may be increasing the cancer risks for people who live in the area to a maximum increase of 13.42 chances in one million of getting cancer. APCD Rule 1210 defines significant health risk thresholds as, and requires public notification and a public meeting, when the cancer risk is at or above 10 in one million, or when any of the non- cancer health hazard indexes or cancer burden is at or above 1.0. As indicated above, for this facility, the maximum residential cancer risk is 13.42, which is above 10 in one million. APCD Rule 1210 also requires facilities with emissions at or above significant health risk thresholds (for cancer the threshold applies to emissions that occurred in calendar year 2018 or later) to submit an application for a risk reduction audit and plan with a proposal on how to reduce their health risks below these thresholds. The APCD has prepared the enclosed “Program Fact Sheet” regarding its Air Toxic Hot Spots Program and a survey card to obtain your questions and comments regarding the information provided in this notice. If you would like more information, please complete and return the enclosed survey card to the APCD via mail, 10124 Old Grove Road, San Diego, 92131, or e-mail at APCDEngineering@sdapcd.org. /~· San Diego County ~Jiilll Air Pollution ~ Control District Additionally, a virtual public meeting has been scheduled for Wednesday, July 6, 2022 at 5 P.M. to discuss the information on this notification and address your questions. Register online prior to the meeting at: https://bit.ly/encinajpa-HRA. For more information regarding the APCD’s Air Toxics Hot Spots program, please contact the APCD at 858-586-2600 or via email at APCDEngineering@sdapcd.org. For more information regarding the facility please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com with Encina Wastewater Authority. Sincerely, PAULA FORBIS Air Pollution Control Officer 10124 Old Grove Rd. San Diego California 92131-1649 (858) 586-2600 Fax (858) 586-2601 www.sdapcd.org June 13, 2022 Dear Employee: State law (Air Toxics "Hot Spots" Information and Assessment Act of 1987) protects your right to know about possible health risks from toxic air contaminants emitted by sources of air pollution in your neighborhood. The San Diego County Air Pollution Control District (APCD) is the local government agency responsible for implementing the Air Toxics “Hot Spots” Program in San Diego County. The following facility is required to notify all employees working in areas where there is a potential health risk at or above the significant risk threshold in accordance with APCD Rule 1210 and hold a public meeting to discuss this information. The enclosed map shows the boundaries of the area that is exposed to health risks at or above the significant risk threshold. Facility Name: Encina Wastewater Authority Address: 6200 Avenida Encinas, Carlsbad, CA 92009 Type of Business: Municipal Wastewater Treatment Based on air emission data in 2017 the APCD requested a health risk assessment from Encina Wastewater Authority. The health risk assessment, approved by the APCD on March 3, 2022, shows that the level of exposure to some toxic air contaminants, primarily formaldehyde and sodium hydroxide resulting from operation of cogeneration engines and wastewater treatment, may result in greater potential for adverse health impacts. Specifically, the Health Risk Assessment shows the Maximum Worker Acute Health Hazard Index is 1.06. The noncancer health hazard index is calculated by dividing the estimated level of exposure to chemicals emitted from a facility to the level of exposure that is not expected to cause any adverse health effects. If the hazard index is less than one (1.0), then the estimated level of exposure is not likely to result in adverse health effects for anyone, including sensitive individuals such as children and the elderly. A hazard index at or above one (1.0) indicates that there may be greater potential for adverse health impacts from exposure to the toxic air contaminants of concern. A hazard index is calculated for both acute (short-term) and chronic (long-term) exposures to air toxic contaminants in facility emissions. APCD Rule 1210 defines significant health risk thresholds as, and requires public notification and a public meeting, when the cancer risk is at or above 10 in one million, or when any of the non-cancer health hazard indexes or cancer burden is at or above 1.0. As indicated above, for this facility, the maximum worker acute health hazard index is 1.06, which is above 1.0. APCD Rule 1210 also requires facilities with emissions at or above significant health risk thresholds (for cancer the threshold applies to emissions that occurred in calendar year 2018 or later) to submit an application for a risk reduction audit and plan with a proposal on how to reduce their health risks /~· San Diego County ~Jiilll Air Pollution ~ Control District below these thresholds. This facility is required to submit an application for a risk reduction audit and plan to APCD by August 30, 2022. If you wish to receive a notice of the plan, please sign up for the APCD GovDelivery subscription service using the following link: https://bit.ly/3JTGsre. Please select the Air Pollution Control District News list. The APCD has prepared the enclosed “Program Fact Sheet” regarding its Air Toxic Hot Spots Program and a survey card to obtain your questions and comments regarding the information provided in this notice. If you would like more information, please complete and return the enclosed survey card to the APCD via mail, 10124 Old Grove Road, San Diego, 92131, or e-mail at APCDEngineering@sdapcd.org. Additionally, a virtual public meeting has been scheduled for Wednesday, July 6, 2022 at 5 P.M. to discuss the information on this notification and address your questions. Register online prior to the meeting at: https://bit.ly/encinajpa-HRA. For more information regarding the APCD’s Air Toxics Hot Spots program, please contact the APCD at 858-586-2600 or via email at APCDEngineering@sdapcd.org. For more information regarding the facility please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com with Encina Wastewater Authority. Sincerely, PAULA FORBIS Air Pollution Control Officer ENCINA WASTEWATER AUTHORITY . . A Public Agency SERVING THE CITY OF VISTA, CITY OF CARLSBAD, BUENA SANITATION DISTRICT, VALLECITOS WATER DISTRICT, LEUCADIA WASTEWATER DISTRICT AND CITY OF ENCINITAS 6200 Avenida Encinas Carlsbad, CA 92011-1095 Telephone (760) 438-3941 FAX (760) 438-3861 (Plant) (760) 431-7493 (Admin) June 15, 2022 Dear Business Owner: Encina Wastewater Authority (Encina) is required by the San Diego County Air Pollution Control District (SDAPCD) to conduct periodic heath risk assessments that evaluate air pollutants released from the Encina Water Pollution Control Facility located at 6200 Avenida Encinas. You are receiving this letter because your business is within an area predicted to have an acute health risk slightly above the public notification threshold as a result of the 2017 facility operations. This letter describes the nature and context of the potential impacts to help you evaluate the information in this required public notification. Health Risk Assessment Health risk assessments provide a theoretical estimate of the chance that a person may experience a health effect from exposure to chemicals based on predictive computer modeling. While any emission of toxic air pollutants is a concern to Encina, the estimated risk discussed in this notice is based on a worst-case scenario of 1-hour exposure to emissions from all sources at the facility operating simultaneously, even though all sources do not operate simultaneously. The health risk assessment used regulatory models that are designed to ensure impacts are not underestimated, for example the toxicity factors include safety and uncertainty factors to adjust the data from animal studies to humans. Risk assessments cannot predict actual health risks or be used to determine if a particular health issue was caused by a chemical. Instead, they are used to support regulatory activities by comparing results to various threshold levels considered protective of human health. Results of Health Risk Assessment The risk assessment conducted by the SDAPCD indicated that two businesses may experience short-term, non-cancer health impacts due to Encina operations. The public notification thresholds are set at a level designed to protect the most sensitive individuals in the population. If an acute risk is predicted to be greater than 1, this means there is a potential for a short-term (1-hour) health impact. The modeling predicted the maximum occupational acute risk to be 1.06, just over the notification threshold. The SDAPCD used maximum hourly emission rates from all sources in the analysis, even though all sources do not operate simultaneously or continuously. Importantly, only three of the four cogeneration engines ever operate simultaneously. Thus, modeling all four engines, plus the emergency generators, in use during 1 hour overestimated the associated health risks. The SDAPCD model included emissions of sodium hydroxide and chlorine from the Odor Reduction System #3 associated with the aerated sludge system by default. These substances were no longer used in the pollution control scrubber in 2017. Therefore, emissions and associated health risks were overestimated. To put these results in perspective, the toxicity factors for the top three chemicals are between 7 and 250 times more health protective than CalOSHA permissible exposure limits. Emission Reduction Measures As part of this Health Risk Assessment, Encina is required to submit a risk reduction plan to the SDAPCD in August 2022. Encina has already eliminated one source of emissions accounted for in the HRA models: at Odor Reduction System #3, Encina discontinued use of sodium hydroxide and chlorine in 2016. The SDAPCD permit was modified in 2016 and again in 2019 to reflect the removal of the caustic scrubber and the use of these chemicals. Without the inclusion of these chemicals from this source, the acute risk drops below the SDAPCD threshold. In addition, Encina implements a Capital Improvement Program and ongoing maintenance programs that replace and evaluate equipment to protect air quality and treat odors from the Water Pollution Control Facility. About Encina Wastewater Authority Encina Wastewater Authority provides essential public services treating up to 43 million gallons per day of wastewater from over 379,000 residents and businesses throughout a 125-square-mile service area. EWA is owned by six public agencies and governed by a Joint Powers Authority (JPA) that includes the Cities of Carlsbad, Vista, and Encinitas as well as Buena Sanitation, Vallecitos Water, and Leucadia Wastewater Districts. The Facility houses complex processes and equipment that protects the local ocean environment, preserves public health, and provides valuable water resources for the region. It also has extensive systems for process odor control, electricity generation from treatment process gas (cogeneration), and biosolids processing that produces a high-quality fertilizer product that is beneficially used. More Information If you would like further information about Encina’s facility, please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com. Sincerely, Alicia Appel Director of Environmental Compliance Encina Wastewater Authority ENCINA WASTEWATER AUTHORITY . . A Public Agency SERVING THE CITY OF VISTA, CITY OF CARLSBAD, BUENA SANITATION DISTRICT, VALLECITOS WATER DISTRICT, LEUCADIA WASTEWATER DISTRICT AND CITY OF ENCINITAS 6200 Avenida Encinas Carlsbad, CA 92011-1095 Telephone (760) 438-3941 FAX (760) 438-3861 (Plant) (760) 431-7493 (Admin) June 15, 2022 Dear Resident: Encina Wastewater Authority (Encina) is required by the San Diego County Air Pollution Control District (SDAPCD) to conduct periodic heath risk assessments that evaluate air pollutants released from the Encina Water Pollution Control Facility located at 6200 Avenida Encinas. You are receiving this letter because you live within an area predicted to have a chance of excess cancer risk slightly above the public notification threshold as a result of the 2017 facility operations. This letter describes the nature and context of the potential impacts to help you evaluate the information in this required public notification. Health Risk Assessment Health risk assessments provide a health protective estimate of the chance that a person may experience a health effect from exposure to chemicals based on computer modeling. While any emission of toxic air pollutants is a concern to Encina, the estimated risk discussed in this notice is based on assuming a person resides in one location 24 hours a day, for 30 years, and is exposed to 2017 facility emission levels. The health risk assessment used regulatory models that are designed to ensure impacts are not underestimated, for example the toxicity factors include safety and uncertainty factors to adjust the data from animal studies to humans. While risk assessments can be used to estimate whether current or future chemical exposures can pose health risks to a broad population, they cannot predict actual health risks or be used to tell us if a particular health issue was caused by a chemical. Results of Health Risk Assessment The risk assessment conducted by the SDAPCD indicated that 14 residences may experience an excess cancer risk greater than 10 in one million, up to 13.42 in a million due to Encina’s wastewater operations. Cancer risk is the probability that a person might contract cancer if exposed to toxic chemical emissions from remaining at an exposed property continuously for 30 years. A cancer risk of 1 in one million means that in a population of one million people, not more than one additional person would have the chance of developing cancer as the result of the exposure to the toxic air pollutant1. 1 https://ww2.arb.ca.gov/resources/documents/health-risk-assessment To put this in perspective, the average Californian has a 720 in one million chance of getting cancer due to the toxics in the ambient air2, with the majority from diesel particulate matter emissions, and there is an approximately 400,000 in one million chance due to all causes3. Emission Reduction Measures The health risk from Encina’s 2017 emissions is below the significant cancer risk threshold of the District Rule 1210 for emissions that occurred prior to year 2018 and therefore, a risk reduction plan is not required at this time. Encina controls emissions by implementing a Capital Improvement Program and ongoing maintenance programs that evaluate, upgrade, and replace equipment to protect air quality and treat odors from the Facility. About Encina Wastewater Authority Encina provides essential public services treating up to 43 million gallons per day of wastewater from over 379,000 residents and businesses throughout a 125-square-mile service area. Encina is owned by six public agencies and governed by a Joint Powers Authority that includes the Cities of Carlsbad, Vista, and Encinitas as well as Buena Sanitation, Vallecitos Water, and Leucadia Wastewater Districts. The Facility houses complex processes and equipment that protects the local ocean environment, preserves public health, and provides valuable water resources for the region. It also has extensive systems for process odor control, electricity generation from treatment process gas (cogeneration), and biosolids processing that produces a high-quality fertilizer product that is beneficially used. More Information If you would like further information about Encina’s facility, please contact Ms. Alicia Appel at (760) 268-8861 or AAppel@encinajpa.com. Sincerely, Alicia Appel Director of Environmental Compliance Encina Wastewater Authority 2 https://ww2.arb.ca.gov/resources/documents/health-risk-assessment 3 https://www.cancer.gov/about-cancer/understanding/statistics ATTACHMENT C Encina Wastewater Authority AB 2588 Health Risk Assessment for Reporting Year 2017 Public Notification Locations ACUTE RECPTORS Receptors with Acute Hazard Indices Greater than Notification Threshold Receptor Number UTM Easting (m) UTM Northing (m) Acute Hazard Index Name Address 95 470,355 3,664,224 1.061 U-Haul Moving & Storage of Carlsbad 6175 Paseo Del Norte, Carlsbad, CA 92011 97 470,364 3,664,207 1.052 94 470,344 3,664,244 1.045 96 470,368 3,664,212 1.004 874 470,029 3,664,379 1.009 Ewing Irrigation & Landscape Supply 6104 Avenida Encinas, Carlsbad, CA 92011 ATTACHMENT C Figure 1: Locations of Receptors with Acute Risk > Public Notification Threshold 469900 469950 470000 Ewing Irrigation & La dscap 6104 Avenida Encinas 470050 470100 470150 470200 UTM East [m] 470250 470300 470350 470400 470450 470500 ATTACHMENT C CANCER RECPTORS Receptors with Cancer Risk Greater than Notification Threshold Receptor Number UTM Easting (m) UTM Northing (m) Cancer Risk (in a million) Name Address 58 470,494 3,664,296 13.415 Seagate Condominium Complex 956 & 958 Tide Ct, Carlsbad, CA 92011 85 470,499 3,664,302 13.232 Seagate Condominium Complex 950 & 954 Tide Ct, Carlsbad, CA 92011 86 470,505 3,664,311 12.957 Seagate Condominium Complex 944 & 952 Tide Ct, Carlsbad, CA 92011 87 470,514 3,664,322 12.412 Seagate Condominium Complex 946 & 948 Tide Ct, Carlsbad, CA 92011 88 470,521 3,664,330 12.012 Seagate Condominium Complex 940 & 942 Tide Ct, Carlsbad, CA 92011 57 470,515 3,664,276 11.943 Seagate Condominium Complex In the neighborhood but not on a structure 1209 470,529 3,664,279 11.414 Seagate Condominium Complex In the neighborhood but not on a structure 1210 470,529 3,664,329 11.634 Seagate Condominium Complex In the neighborhood but not on a structure There are no receptors at the following addresses, but they fall within the 10 in a million isopleth Seagate Condominium Complex 932, 934, 936 & 938 Tide Ct, Carlsbad, CA 92011 Receptors with Cancer Risk LESS THAN Notification Threshold Receptor Number UTM Easting (m) UTM Northing (m) Cancer Risk (in a million) Name Address 1251 470,579 3,664,329 9.707 Seagate Condominium Complex 922, 924, 926 & 928 Tide Ct ATTACHMENT C Figure 2: Locations of Receptors with Cancer Risk > Public Notification Threshold 470490 470500 470510 470520 470530 470540 470550 470560 470570 470580 470590 470600 470610 470620 470630 470640 UTM East [m]