Release-Based Cleanup Regulations

1. (a) Definitions For the purposes of the RBCRs, the following terms have the following meanings:

   1. (1) “Accessory uses of land” means any use of a parcel of land that is not the primary use of that parcel of land;
   2. (2) “Active recreation” means any recreational activity that is not “passive recreation activity” as it is defined in subdivision (100) of this subsection;
   3. (3) “Active remediation” means remediation but does not include determining the nature and extent of a release or monitored natural attenuation;
   4. (4) “Application of pesticides” means the spraying, spreading, injection, placement, or other use of pesticides at a parcel for the pesticide’s intended purpose, but does not include other releases of pesticides such as those from the handling, mixing, storing, spilling, leaking or disposing of pesticides, or releases of pesticides from equipment cleaning or repair;
   5. (5) “Aquifer protection area” has the same meaning as provided in section 22a-354h of the Connecticut General Statutes;
   6. (6) “Area of influence” has the same meaning as provided in section 22a-354b-1(a)(3) of the Regulations of Connecticut State Agencies;
   7. (7) “Areal extent of a groundwater plume” means the surface area beneath which groundwater is polluted by a release and in which one or more substances from such release or mobilized by such release is present at a concentration above the laboratory reporting limit;
   8. (8) “Assessment of the secondary containment system” means an inspection or examination of a secondary containment system to ensure it is free of cracks, gaps, or voids and is functioning as designed and intended;
   9. (9) “Association or professional property management company” means a common interest community association, homeowners association, or company authorized to monitor compliance with declarations, bylaws, lease agreements, or other documents enforceable by such association or company and to maintain a parcel of land;
   10. (10) “Audit” means the commissioner’s review of an LEP verification or PEP certification pursuant to section 22a-134tt-13 of the RBCRs;
   11. (11) “Automotive exhaust” means the substances which are byproducts of the reaction within an internal combustion engine and are expelled by those automobiles which rely on internal combustion engines for propulsion;

   12. (12) “Background concentration” means the concentration of a substance in soil or groundwater that, based on a validated conceptual site model, is:

       1. (A) In the general geographic vicinity of a release; and(B) Either:

2. (i) Naturally occurring; or(ii) Minimally affected by human influences at concentrations equal to or less than criteria specified in the RBCRs;

   1. (13) “Base annual fee” means the fee calculated and paid the first time a release is assigned to a tier pursuant to section 22a-134tt-6(f)(2)(A) of the RBCRs;
   2. (14) “Business day” means all calendar days, other than Saturdays, Sundays and days designated as national or State of Connecticut holidays on which banks in Connecticut are closed;
   3. (15) “Carcinogenic substance” means a substance defined as a “carcinogen” by federal or state agencies and for which a quantitative health risk extrapolation is available;

   4. (16) “Certification” means either:

      1. (A) An attestation on a form prescribed by the commissioner as to the accuracy of the information provided on such form; or(B) The written opinion of a permitted environmental professional on a form prescribed by the commissioner that the remediation of a release satisfies the standards established in the RBCRs;
   5. (17) “CFR” means the Code of Federal Regulations;
   6. (18) “Change in tier assignment” means the assignment of a release to a different tier following the process specified in section 22a-134tt-6(c)(2) of the RBCRs;
   7. (19) “Characterization” means determining the nature and extent of a release in accordance with prevailing standards and guidelines;
   8. (20) “Chloride-based, inorganic salt” means an inorganic substance containing chloride, including sodium chloride, calcium chloride, magnesium chloride or any other inorganic substance containing chloride;
   9. (21) “Cleanup standards sections” means sections 22a-134tt-7 to 22a-134tt-10, inclusive, of the RBCRs;
   10. (22) “Commissioner” means the Commissioner of Energy and Environmental Protection or the designated agent of the commissioner;
   11. (23) “Closure characterization” means characterization of a release such that the horizontal and vertical extent of such release is delineated to the points at which it is no longer detected or that the extent of such release has otherwise been determined in a manner consistent with prevailing standards and guidelines, provided delineation to the point at which a release is no longer detected for all releases shall not be required;
   12. (24) “Conceptual site model” means a representation in 3 dimensions of environmental conditions at a release area that is developed through a multi-phased investigative approach which validates such representation with information about, including, but not limited to, a substance’s release, fate and transport, and pathway to human and environmental receptors;
   13. (25) “Data” means facts and statistics, including, but not limited to, analytical data and recorded observations;
   14. (26) “Date of tier assignment” means the date specified by section 22a-134tt-6(c)(4)(D) of the RBCRs;
   15. (27) “Demarcation layer” means a brightly-colored, tear-resistant, environmentally-stable marker layer installed at an appropriate depth, suitable to indicate the presence of polluted soil beneath such layer;
   16. (28) “Department” means the Department of Energy and Environmental Protection;
   17. (29) “Dilution factor” means the ratio by which the concentration of a substance dissolving into soil water is reduced by dilution with groundwater or surface water, as applicable;
   18. (30) “Dilution and attenuation factor” or “Dilution attenuation factor” means the ratio by which the concentration of a substance dissolving into soil water is reduced by dilution with groundwater and by sorption to unsaturated or saturated soil, or by degradation, transformation or stabilization of the substance;

   19. (31) “Diminishing state groundwater plume” means a groundwater plume that has been characterized seasonally and in 3 dimensions, provided that the characterization of such plume:

       1. (A) Is consistent with a validated conceptual site model; and(B) Demonstrates that such plume:

3. (i) Is not migrating, or has very limited potential to migrate, in any direction; and(ii) Is comprised only of substances whose concentrations have decreased and will continue to decrease over time, except for the concentrations of related breakdown components, provided it is demonstrated that concentrations of such breakdown components are not a known risk to human health and the environment. For purposes of this clause, “breakdown components” means constituent compounds that result from the alteration of an original compound in the environment;

   1. (32) “Direct exposure criteria” or “DEC” means the criteria identified in section 22a-134tt-App2 of the RBCRs, alternative direct exposure criteria approved by the commissioner pursuant to section 22a-134tt-9(d) of the RBCRs, or direct exposure criteria approved by the commissioner pursuant to section 22a-134tt-9(b)(7) of the RBCRs;
   2. (33) “Downgradient” means in the direction of the maximum rate of decrease of hydraulic head;

   3. (34) “Downgradient area” with respect to a release of a substance means the area bounded by:

      1. (A) The width of the release area of such substance perpendicular to the direction of groundwater flow;
      2. (B) 2 side boundary lines parallel to the downgradient direction of groundwater flow extending from the 2 endpoints of said width to the downgradient parcel boundary; and(C) The downgradient parcel boundary extending between the 2 side boundary lines, excluding any portion of such downgradient area that is either affected by any other release of such substance or beneath an existing permanent structure;
   4. (35) “Dwelling unit” means a single family home or a section of a larger structure where a person or family eats, lives, and sleeps, such as a multi-family house, apartment, mobile home, or set of rooms;
   5. (36) “Drinking water supply well” means an artificial excavation constructed by any method for the purpose of obtaining or providing water for drinking or other domestic, industrial, commercial, agricultural, recreational or irrigation use, or other outdoor water use;

   6. (37) “Emergent reportable release” means a release to the land and waters of the state discovered by an observed change in conditions that is required to be reported by regulations adopted pursuant to section 22a-450 of the Connecticut General Statutes. “Emergent reportable release” does not include:

      1. (A) A release required to be reported pursuant to section 22a-450-2(a)(2) or 22a-450-2(a)(3) of the Regulations of Connecticut State Agencies if the quantity of the release is less than 10 gallons; and(B) A release required to be reported pursuant to section 22a-450-2(b)(2) or 22a-450-2(b)(3) of the Regulations of Connecticut State Agencies if the quantity of the release is less than 20 pounds or 3 gallons;
   7. (38) “Engineered control” means any physical barrier, system, technology or method that prevents exposure to polluted soil, or minimizes migration of liquids or vapor through such soil, and complies with the other requirements specified in section 22a-134tt-9(f)(2) of the RBCRs;
   8. (39) “Environmental land use restriction” or “ELUR” has the same meaning as provided in section 22a-133q-1(3) of the Regulations of Connecticut State Agencies;
   9. (40) “Environmental use restriction” or “EUR” has the same meaning as provided in section 22a- 133q-1(4) of the Regulations of Connecticut State Agencies;
   10. (41) “Environmentally isolated soil” means polluted soil which is above the seasonal high water table and is not subject to infiltration in accordance with section 22a-134tt-9(c)(5)(A) of the RBCRs, thereby preventing the leaching of pollutants from such soil into groundwater;
   11. (42) “EPA” means the United States Environmental Protection Agency;
   12. (43) “ETPH” means extractable total petroleum hydrocarbons;
   13. (44) “EUR regulations” has the same meaning as provided in section 22a-133q-1(7) of the Regulations of Connecticut State Agencies;
   14. (45) “Excess lifetime cancer risk” means the estimated probability that an individual’s exposure to a substance could result in cancer;
   15. (46) “Exigent condition” means a condition which exists or occurs as a result of a release that the commissioner determines, in the commissioner’s sole discretion, requires the department to respond to such release to abate such a condition;
   16. (47) “Existing release” means a release discovered through the laboratory analysis of samples taken from the land and waters of the state;
   17. (48) “Fertilizer” has the same meaning as provided in section 22-111b of the Connecticut General Statutes;
   18. (49) “GA area” means an area where the groundwater classification is GA, GAA, or GAAs;
   19. (50) “GB area” means an area where the groundwater classification is GB;
   20. (51) “Ground surface” means any horizontal surface at or near ground level, including, but not limited to, soil, grass, sidewalks, and driveways;
   21. (52) “Groundwater” means that portion of waters, as defined in section 22a-423 of the Connecticut General Statutes, at or below the water table;
   22. (53) “Groundwater classification” means the groundwater classification established in the water quality standards;
   23. (54) “Groundwater criteria” means surface-water protection criteria, water quality criteria, volatilization criteria, groundwater protection criteria, and background concentration, as applicable;
   24. (55) “Groundwater divide” means a line on the water table from which the water table slopes downward in both directions away from such line;
   25. (56) “Groundwater monitoring well” means a well constructed for the purpose of aquifer testing, obtaining samples of ground water quality and/or measurement of ground water level;
   26. (57) “Groundwater plume” means groundwater that has been impacted by a release and is emanating from a release area and in which one or more substances from such release is present at a concentration above the laboratory reporting limit;
   27. (58) “Groundwater protection criteria” or “GWPC” means the criteria identified in section 22a-134tt-App4 of the RBCRs, alternative groundwater protection criteria calculated by an LEP or approved by the commissioner pursuant to section 22a-133k-10(d)(2) of the RBCRs, or groundwater protection criteria approved by the commissioner pursuant to section 22a-134tt-10(i)(1) of the RBCRs;
   28. (59) “Hardscape” means man-made features that are incorporated into landscaped areas, including walkways constructed with asphalt, concrete, or pavers; gravel parking areas and driveways; paved or gravel storm water features; placement of natural rock; rip-rap; and non-vegetated retaining walls;
   29. (60) “Hazard index” means the calculation of the potential for non-cancer health effects as a result of exposure to one or more substances with the same or similar modes of toxic action or toxic endpoints;
   30. (61) “Historically impacted material” means polluted material that will be managed in accordance with the conditional exemption for historically impacted material pursuant to section 22a-134tt-9(j) of the RBCRs;
   31. (62) “Home heating fuel” means any petroleum-based fuel, including any petroleum product regulated pursuant to chapter 250 of the Connecticut General Statutes, used as the primary source of residential heating or domestic hot water;
   32. (63) “Hydraulic gradient” means the change in hydraulic head per unit distance;
   33. (64) “Hydraulic head” means the elevation to which water rises in a piezometer or a well;
   34. (65) “Immediate action” means the remediation necessary to comply with the requirements established by section 22a-134tt-5 of the RBCRs;
   35. (66) “Immobilization” or “Immobilize” means the act of binding a substance to create a solid that is resistant to leaching and eliminates or virtually eliminates the mobility of a substance from such solid, including, but not limited to, solidification to physically bind or enclose a substance within a stabilized mass, stabilization through chemical reactions between a stabilizing agent and a substance, or encapsulation by coating a substance;
   36. (67) “Impervious surface” means a surface composed of any material that prevents infiltration of water into the soil which shall include, but is not limited to, concrete or bituminous concrete;
   37. (68) “Improved surface” means an area of soil uniformly covered by pavement, concrete, stone, or other similar material except any secondary containment system;

   38. (69) “Inaccessible soil” means soil that meets at least one of the following conditions:

       1. (A) Is more than 4 feet below the ground surface;
       2. (B) Is more than 2 feet below a paved ground surface comprised of bituminous concrete that, at a minimum, is 3 inches thick or reinforced concrete that, at a minimum, is 4 inches thick;
       3. (C) Is beneath a building or other permanent structure;
       4. (D) Is polluted material:

4. (i) Beneath a paved ground surface comprised of bituminous concrete that, at a minimum, is 3 inches thick or reinforced concrete that, at a minimum, is 4 inches thick; and(ii) That exceeds the applicable direct exposure criteria solely due to:

   1. (I) Semi-volatile organic substances or petroleum hydrocarbons that are normal constituents of bituminous concrete; or(II) Metals at concentrations that are equal to or less than 2 times the applicable direct exposure criteria; or(E) Is located beneath concrete or bituminous concrete and complies with the applicable requirements of subparagraphs (B) and (C) of subdivision (3) of subsection (b) of section 22a-134tt-9 of the RBCRs.
   2. (70) “Incidental Public Roadway Release” means an existing release of asphalt or asphalt byproducts, petroleum hydrocarbons, or other substances to asphalt or soil in the right of way of a public roadway that is present due to the operation of passenger motor vehicles and is not a significant existing release, or is a release of chloride-based, inorganic salt.
   3. (71) “Indoor air” means the portion of the atmosphere interior to buildings;
   4. (72) “Immediate action plan” means a plan prepared pursuant to section 22a-134tt-5(j) of the RBCRs;
   5. (73) “Immediate action report” means a report prepared pursuant to section 22a-134tt-5(k) of the RBCRs;
   6. (74) “Industrial/commercial activity” means any activity related to the commercial production, distribution, manufacture or sale of goods, services, or any other activity which is not a residential activity;
   7. (75) “Industrial/commercial direct exposure criteria” means the criteria identified as industrial/commercial direct exposure criteria in section 22a-134tt-App2 of the RBCRs, alternative direct exposure criteria approved by the commissioner pursuant to section 22a-134tt-9(d) of the RBCRs, or direct exposure criteria approved by the commissioner pursuant to section 22a-133k-9(b)(7) of the RBCRs;
   8. (76) “Industrial/commercial volatilization criteria” means the criteria identified as industrial/commercial volatilization criteria in sections 22a-134tt-App6 and 22a-134tt-App7 of the RBCRs, alternative volatilization criteria approved by the commissioner pursuant to section 22a- 134tt-10(c)(4) of the RBCRs, or volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(i)(3) of the RBCRs;
   9. (77) “Intermittent watercourse” means a type of watercourse, as defined in section 22a-38 of the Connecticut General Statutes, that is delineated as described in section 22a-38 of the Connecticut General Statutes;
   10. (78) “Knowledge” means a person knows of a release because such person is aware of 1 or more of the types of information specified at section 22a-134tt-2(b) of the RBCRs;
   11. (79) “Laboratory reporting limit” means the lowest concentration at which an analyte can be detected in a sample of environmental media by a laboratory certified by the Department of Public Health pursuant to section 19a-29a of the Connecticut General Statutes and which concentration can be reported with a reasonable degree of accuracy and precision pursuant to section 22a-134tt-1(d) of the RBCRs;
   12. (80) “Land and waters of the state” has the same meaning as provided in section 22a-134pp(3) of the Connecticut General Statutes.
   13. (81) “Licensed environmental professional” or “LEP” means an environmental professional who has a current valid license issued by the commissioner pursuant to section 22a-133v of the Connecticut General Statutes;
   14. (82) “Managed multifamily residential activity” means activity at any parcel with 4 or more dwelling units, provided such dwelling units are managed by an association or a professional property management company;
   15. (83) “Managed multifamily residential direct exposure criteria” means the criteria identified as managed multifamily residential direct exposure criteria in section 22a-134tt-App11 of the RBCRs or an alternative direct exposure criteria approved by the commissioner pursuant to section 22a-134tt-9(d) of the RBCRs;
   16. (84) “Matrix interference” means either a positive or negative effect when measuring the concentration of a substance in a sample that creates erroneous results for an analyte;
   17. (85) “Maximum extent practicable” means the greatest degree of remediation that can be achieved using sound engineering and hydrogeologic practices without taking cost into consideration;
   18. (86) “Maximum extent prudent” means the greatest degree of remediation that can be achieved using sound engineering and hydrogeologic practices that the commissioner deems reasonable, taking into consideration cost in proportion to social and environmental benefits, provided that a mere showing of expense will not necessarily render a remediation option unreasonable;

   19. (87) “Monitored natural attenuation” means representative groundwater monitoring of the natural attenuation of each substance in a groundwater plume to a concentration equal to or less than groundwater criteria, provided such monitoring demonstrates that:

       1. (A) Such attenuation is occurring, and will continue to occur, as evidenced by changes in chemical concentrations, alterations of chemical components, and hydrogeologic conditions within the aquifer after completing the remediation of a release area in a manner that will achieve compliance with the RBCRs; and(B) The only remaining groundwater plume from a release is a diminishing state groundwater plume;
   20. (88) “Multiple lines of evidence” means 2 or more types of observable facts which tend to demonstrate the truth of a matter asserted;
   21. (89) “Municipality” has the same meaning as provided in section 22a-134pp(4) of the Connecticut General Statutes.
   22. (90) “Natural attenuation” means a decrease in concentration of a substance in groundwater through operation of natural physical or chemical processes, including, but not limited to, adsorption, absorption, dilution, phase transfer, oxidation, organic complexation, biodegradation, dispersion, and diffusion;
   23. (91) “Naturally occurring” means present in the environment in forms that have not been influenced by human activity;
   24. (92) “95 percent upper confidence level of the arithmetic mean” means a value that, when repeatedly calculated for randomly drawn subsets of size n from a population, equals or exceeds the population arithmetic mean 95 percent of the time;
   25. (93) “Non-aqueous phase liquid” or “NAPL” means a liquid that is not dissolved in water;
   26. (94) “Notice of Activity and Use Limitation” or “NAUL” has the same meaning provided in section 22a-133q-1(14) of the Regulations of Connecticut State Agencies;
   27. (95) “Numeric cleanup standards” means those cleanup standards identified in sections 22a-134tt-APP2 to 22a-134tt-APP12, inclusive, of the RBCRs;
   28. (96) “Oil or petroleum” means oil or petroleum of any kind or in any form, including, but not limited to, crude oil or fractions thereof, refined petroleum or fractions thereof, biofuels, waste oils, mineral oils, dielectric fluids and distillation products such as heating oils, diesel fuels, fuel oil, kerosene, naphtha, gasoline, and lubricating and hydraulic oils;
   29. (97) “Organoleptic” means the capability to produce a detectable sensory stimulus such as odor or taste;
   30. (98) “Parcel” means a piece, tract, or lot of land, together with the buildings and other improvements situated thereon, a legal description of which is contained in a deed or other instrument of conveyance;
   31. (99) “Parcel-wide investigation” means an investigation of an entire parcel of land conducted pursuant to the site characterization guidance document published by the commissioner on the department’s internet website, or by another method consistent with prevailing standards and guidelines approved in writing by the commissioner;
   32. (100) “Passive recreation activity” means recreational activities that do not encourage sustained activity in a discrete area or do not require development of prepared facilities like sports fields, courts, beaches, or buildings, but does include recreation activities that use paved or unpaved walking trails or roads integral to such passive recreational use;
   33. (101) “Passive recreation direct exposure criteria” means the criteria identified as passive recreation direct exposure criteria in section 22a-134tt-App12 of the RBCRs, or an alternative direct exposure criteria approved by the commissioner pursuant to section 22a-134tt-9(d) of the RBCRs;
   34. (102) “PCBs” means polychlorinated biphenyls;
   35. (103) “Permitted Environmental Professional” or “PEP” means a person authorized by a permit issued pursuant to section 22a-454 of the Connecticut General Statutes to certify release records;
   36. (104) “Person” has the same meaning as provided in section 22a-134pp(5) of the Connecticut General Statutes;
   37. (105) “Persistent impact to groundwater” means the presence of a release in groundwater after more than 24 hours;
   38. (106) “Pesticide” has the same meaning as provided in section 22a-47(w) of the Connecticut General Statutes;
   39. (107) “Per- and polyfluoroalkyl substances” or “PFAS” means man-made chemicals with at least one fully fluorinated carbon atom, including but not limited to perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS);
   40. (108) “Pollutant mobility criteria” or “PMC” means the criteria identified in section 22a-134tt-App3 of the RBCRs, alternative pollutant mobility criteria calculated by an LEP or approved by the commissioner pursuant to section 22a-134tt-9(d) of the RBCRs, or pollutant mobility criteria approved by the commissioner pursuant to section 22a-134tt-9(c)(6) of the RBCRs;
   41. (109) “Polluted fill” means soil which contained polluting substances at the time such soil was deposited as fill material;
   42. (110) “Polluted material” means soil that has been historically intermixed with coal ash, wood ash, coal fragments, coal slag, coal clinkers, asphalt paving fragments, or any combination thereof;
   43. (111) “Polluted soil” means soil affected by a release of a substance at a concentration above the laboratory reporting limit for such substance;
   44. (112) “Pollution” has the same meaning as provided in section 22a-423 of the Connecticut General Statutes;
   45. (113) “Potential public water supply resource” means any “potential well fields” as defined in section 22a-354a of the Connecticut General Statutes, or any area mapped by the commissioner pursuant to section 22a-354c(b) of the Connecticut General Statutes;
   46. (114) “PPB” means parts per billion;
   47. (115) “PPM” means parts per million;
   48. (116) “Practicable” means the greatest degree of remediation that can be achieved using sound engineering and hydrogeologic practices without taking cost into consideration;
   49. (117) “Preferential pathway” means a high-permeability conduit that allows contamination to migrate through soils and groundwater at a faster rate than would be expected through naturally occurring undisturbed soils or unfractured bedrock such as a utility penetration; line; drain; building sump or drainage pit; elevator shaft; fractured bedrock; or gravel;
   50. (118) “Private drinking water supply well” means a drinking water supply well that services a single dwelling unit;
   51. (119) “Properly constructed and developed groundwater monitoring well” means a well that provides samples that are representative of groundwater;
   52. (120) “Prudent” means reasonable, taking into consideration cost in proportion to social and environmental benefits;
   53. (121) “Public roadway” means any portion of a federal, state, town, or other public highway, including, but not limited to, road, street, parkway, limited access highway, boulevard, or avenue paved with bituminous concrete or concrete, under the control of the federal government, the state or any political subdivision of the state, any quasi-governmental entity or municipal economic development agency or entity created or operating under the Connecticut General Statutes, that is dedicated, appropriated, or open to the movement of vehicles or pedestrians, including appurtenant sidewalks, medians, and shoulders, but excluding landscaped or grassy areas beyond the outer edge of the travel way;
   54. (122) “Public water supply distribution system” means any combination of pipes, tanks, pumps, etc. which deliver water from the source or treatment facility to the consumer from any water company, as defined in section 25-32a of the Connecticut General Statutes, supplying water to 2 or more consumers, or 25 or more persons daily, at least 60 days of the year;
   55. (123) “Public drinking water supply well” means a drinking water supply well that services multiple dwelling units;
   56. (124) “Q99” means the daily stream flow that is predicted to be equaled or exceeded on 99 percent of days in a year, and is calculated using methods developed by the U.S. Geological Survey (StreamStats);
   57. (125) “Reasonable confidence protocols” or “RCPs” means any reasonable confidence protocols, quality assurance requirements, or quality control requirements, posted by the commissioner on the department’s internet website, regarding the laboratory measurements of the concentration of a substance in a sample;
   58. (126) “Release” has the same meaning as provided in section 22a-134pp(6) of the Connecticut General Statutes;
   59. (127) “Release-based cleanup regulations” or “RBCRs” means sections 22a-134tt-1 to 22a-134tt-APP12, inclusive, of the Regulations of Connecticut State Agencies;
   60. (128) “Release area” means the land area at or beneath which the land and waters of the state are impacted by a release;
   61. (129) “Release record” means a document certified by a PEP or verified by an LEP documenting compliance with a requirement or requirements of the RBCRs;
   62. (130) “Release remediation closure report” means a report prepared pursuant to section 22a-134tt-12 of the RBCRs.
   63. (131) “Remediation” has the same meaning as provided in section 22a-134pp(7) of the Connecticut General Statutes;
   64. (132) “Report” means to notify the commissioner of a release in accordance with the RBCRs or the regulations adopted pursuant to section 22a-450 of the Connecticut General Statutes, and in the manner specified by the commissioner;

   65. (133) “Residential activity” means any activity at:

       1. (A) A place intended for people to live, including, but not limited to, a residence, dwelling, house, apartment, condominium, nursing home, or dormitory;
       2. (B) A pre-school, primary school, secondary school, day care center, playground, or outdoor recreational area; or(C) A hospital, solely for the purposes of compliance with volatilization criteria;
   66. (134) “Residential direct exposure criteria” means the criteria identified as residential direct exposure criteria in 22a-134tt-App2 of the RBCRs, alternative direct exposure criteria approved pursuant to section 22a-134tt-9(d) of the RBCRs, or direct exposure criteria approved by the commissioner pursuant to section 22a-134tt-9(b)(7) of the RBCRs;
   67. (135) “Residential volatilization criteria” means the criteria identified as residential volatilization criteria in sections 22a-134tt-App6 and 22a-134tt-App7 of the RBCRs, alternative volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(c)(4) of the RBCRs, or volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(i)(3) of the RBCRs;
   68. (136) “Scoping level ecological risk assessment” means visual observation of potential pathways from a release to ecological receptors;
   69. (137) “Screening level ecological risk assessment” means confirming pathways from a release to ecological receptors through results of laboratory analysis of representative samples;
   70. (138) “Seasonal high water table” means, on an annual basis, the highest plane in the ground at which all pore spaces are filled with water at atmospheric pressure;
   71. (139) “Seasonal low water table” means, on an annual basis, the lowest plane in the ground at which all pore spaces are filled with water at atmospheric pressure;
   72. (140) “Secondary containment system” means a system serving one or more primary storage containers or tanks that is designed, installed and operated to collect and contain a release of a reportable material in the event of loss of the integrity or failure of the primary containment;
   73. (141) “Sediment” means unconsolidated material occurring in a watercourse, as defined in section 22a-38 of the Connecticut General Statutes, and in estuarine water or marine water;
   74. (142) “Semi-volatile organic substance” means an organic substance that has a higher molecular weight and higher boiling point than a volatile organic substance;
   75. (143) “Significant existing release” means a release to the land and waters of the state discovered pursuant to section 22a-134tt-2 of the RBCRs that is present in the location identified in, or creating one or more of the impacts to human health or the environment identified in, section 22a-134tt-5(e) of the RBCRs;
   76. (144) “Site-specific ecological risk analysis” means the full delineation and evaluation of pathways and impacts from a release to ecological receptors;
   77. (145) “Soil” means unconsolidated geologic material overlying bedrock, including, but not limited to, sediment that has been removed from any surface water body and placed on dry land;
   78. (146) “Soil water” means that portion of waters, as defined in section 22a-423 of the Connecticut General Statutes, which is above the water table;
   79. (147) “Soil vapor” means gaseous substances in the space between particles of soil;
   80. (148) “Solid, liquid or gaseous products” has the same meaning as provided in section 22a-450-1(39) of the Regulations of Connecticut State Agencies;
   81. (149) “SPLP” means Synthetic Precipitation Leaching Procedure EPA Method 1312 as set forth in “Test Methods for Evaluating Solid Waste: Physical/Chemical Methods”, SW-846, U.S. Environmental Protection Agency, Office of Solid Waste, Washington D.C. 20460;
   82. (150) “Subject area” means an area where the RBCRs require an EUR to be placed and maintained as part of the selected remedial approach. “Subject area” includes the area subject to the restrictions and requirements of an EUR after such EUR has been recorded. There can be multiple subject areas on a parcel, or an entire parcel may comprise a single subject area;
   83. (151) “Substance” means an element, compound or material which, when added to air, water, soil or sediment, may alter the physical, chemical, biological or other characteristic of such air, water, soil or sediment;
   84. (152) “Surface water” has the same meaning as provided in section 22a-426-1(60) of the Regulations of Connecticut State Agencies;
   85. (153) “Surface-water protection criteria” or “SWPC” means the criteria identified in section 22a-134tt-App5 of the RBCRs, alternative surface-water protection criteria calculated by an LEP or approved by the commissioner pursuant to section 22a-134tt-10(b) of the RBCRs, or surface-water protection criteria approved by the commissioner pursuant to section 22a-134tt-10(i)(2) of the RBCRs;
   86. (154) “Target indoor air concentrations” means risk-based indoor air concentrations developed in consultation with the Department of Public Health that are not expected to cause adverse health effects from chronic exposure;
   87. (155) “TCLP” means Toxicity Characteristic Leaching Procedure EPA Method 1311 as set forth in “Test Methods for Evaluating Solid Waste: Physical/Chemical Methods”, SW-846, U.S. Environmental Protection Agency, Office of Solid Waste, Washington D.C. 20460;
   88. (156) “Technically impracticable” means a determination by the commissioner that further reduction of the concentration of a substance in soil or groundwater cannot be achieved using sound engineering and hydrogeologic remediation practices;
   89. (157) “TI zone” means the areal extent of a substance that is technically impracticable to remediate to the applicable groundwater criteria;

   90. (158) “Tier” means either:

       1. (A) One of the categories established under 22a-134tt-6(b)(1) of the RBCRs; or(B) The act of assigning a release to one of the categories identified in 22a-134tt-6(b)(1) of the RBCRs, pursuant to the process specified in 22a-134tt-6 of the RBCRs;

   91. (159) “Tier characterization” means delineation of the nature and extent of each substance present in the land and waters of the state at a concentration that exceeds 50 percent of the applicable cleanup standard, or the applicable laboratory reporting limit, whichever is higher, or a demonstration that each substance is present in soil or groundwater at a level less than or equal to the background concentration has been made, using the standards identified in section 22a-134tt-4 of the RBCRs, except that:

       1. (A) Pesticides shall be characterized to the extent needed to determine that pesticides discovered are present due to the application of pesticides. If such a determination is made, no further characterization of pesticides present due to the application of pesticides shall be required for tier characterization; and, pesticides present due to spraying, spreading, injecting, placing or other use of pesticides for the pesticide’s intended purpose and consistent with its labeling shall not require further characterization for the purposes of tier characterization; and(B) A release of polluted material that is discovered on a parcel currently used only for industrial/commercial activity may be characterized only to the extent needed to determine that it is prudent to remediate the polluted material using the conditional exemption for historically impacted material, pursuant to section 22a-134tt-9(j) of the RBCRs;
   92. (160) “Underground storage tank system” or “UST system” means an underground storage tank and any associated ancillary equipment and containment system;
   93. (161) “Underground storage tank system regulations” means regulations adopted pursuant to section 22a-449(d) of the Connecticut General Statutes;
   94. (162) “Upgradient” means in the direction of maximum rate of increase of hydraulic head;

   95. (163) “Upgradient area” with respect to a release area of a substance means the area bounded by:

       1. (A) The width of the release area of such substance perpendicular to the direction of groundwater flow;
       2. (B) 2 side boundary lines parallel to the upgradient direction of groundwater flow extending from the 2 endpoints of said width to the upgradient parcel boundary; and(C) The upgradient parcel boundary extending between the 2 side boundary lines, excluding any portion of such upgradient area that is affected by any other release of such substance, or beneath an existing permanent structure;
   96. (164) “Vapor mitigation system” means technology employed to mitigate real or potential impacts from vapor intrusion;
   97. (165) “Verification” has the same meaning as provided in section 22a-134pp(9) of the Connecticut General Statutes;
   98. (166) “Volatilization criteria” means the criteria identified in sections 22a-134tt-App6 and 22a-134tt-App7 of the RBCRs, alternative volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(c)(4) of the RBCRs, or volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(i)(3) of the RBCRs;
   99. (167) “Volatilization criteria for groundwater” means the criteria identified in section 22a-134tt-App6 of the RBCRs, alternative volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(c)(4) of the RBCRs, or volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(i)(3) of the RBCRs;
   100. (168) “Volatilization criteria for soil vapor” means the criteria identified in section 22a-134tt-App7 of the RBCRs, alternative volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(c)(4) of the RBCRs, or volatilization criteria approved by the commissioner pursuant to section 22a-134tt-10(i)(3) of the RBCRs;
   101. (169) “Volatile organic substance” means an organic substance that has a high vapor pressure and low boiling point at room temperature;
   102. (170) “Volatile petroleum substance” means a volatile organic substance found in gasoline, diesel fuel, fuel oil, heating oil, kerosene, jet fuel, or similar fuels, along with volatile organic substances that may have been used as fuel additives;
   103. (171) “Water table” means the plane in the ground at which all pore spaces are filled with water at atmospheric pressure;
   104. (172) “Water quality criteria” or “WQC” means the lower of the human health or aquatic life criteria contained in Table 3 of the water quality standards;
   105. (173) “Water quality standards” means the Connecticut Water Quality Standards in sections 22a-426-1 to 22a-426-9, inclusive, of the Regulations of Connecticut State Agencies and the Classification Maps adopted pursuant to section 22a-426 of the Connecticut General Statutes;
   106. (174) “Wetland” has the same meaning as “wetlands” provided in section 22a-38(15) of the Connecticut General Statutes.
5. (b) Construction of Regulations In the construction of the RBCRs, terms or words in the singular may be construed and applied to more than one thing and terms or words in the plural may be construed and applied to the singular or just one thing.

6. (c) Use of Form Prescribed by the Commissioner (1) Any submittal to the commissioner under the RBCRs, including, but not limited to, a request for a variance, approval, notice, financial assurance, or EUR shall be submitted in writing on a form prescribed by the commissioner. Any such form may require the following information:

   1. (A) A description of the subject release;
   2. (B) A description of the distribution and concentration of substances in soil and groundwater resulting from the subject release;
   3. (C) The general characteristics of soil in the vicinity of the subject release area;
   4. (D) A map showing the extent of all release areas on a parcel and the subject release area, including all sample locations;
   5. (E) A map showing the extent of the subject groundwater plume and the concentration of substances in such plume;
   6. (F) The tabulated analytical results of all laboratory analyses of soil and groundwater at the subject release area;
   7. (G) A detailed justification for any variance or approval requested;
   8. (H) Any information specifically required by the RBCRs;
   9. (I) A signed certification by the person submitting the form and, if provided on the form, certification by an LEP; and(J) Any other information deemed necessary by the commissioner.
   10. (2) If an electronic system is available for any submission identified in subdivision (1) of this subsection, such submittal shall be made pursuant to the instructions prescribed by the commissioner for the use of such electronic system.
7. (d) General Requirements for Analytical Data (1) Analytical Data Quality and Usability (A) With respect to analytical data, the following shall apply:

8. (i) All analytical data used to comply with the RBCRs shall be scientifically valid and defensible, with a level of precision, accuracy, and sensitivity commensurate with its intended use. All analytical data submitted shall include an analytical data quality assessment and data usability evaluation prepared by individuals qualified to make such assessment or evaluation; and(ii) If the commissioner determines that analytical data is not scientifically valid and defensible, or not of a sufficient level of precision, accuracy, and sensitivity to support the intended use of the data, the commissioner shall identify in writing the reasons for such conclusions and such data shall not be relied upon to demonstrate compliance with the RBCRs.

   1. (B) The commissioner may specify, by posting on the department’s internet website, methods or protocols to ensure that analytical data is of known and documented quality, including, but not limited to:

9. (i) RCPs for laboratory quality assurance and quality control measures or analytical methods for the evaluation of soil, sediment, groundwater, air, or soil vapor;

   1. (ii) RCPs to be followed when establishing laboratory reporting limits; and(iii) Methods and protocols for assessing data quality and evaluating data usability which can be used to determine whether data is scientifically valid and defensible, with a level of precision, accuracy, and sensitivity commensurate with its intended use.
   2. (C) If an analytical data quality assessment or usability evaluation is conducted using a method or protocol other than the methods and protocols prescribed by the commissioner pursuant to this subdivision, such methods and protocols shall be documented and submitted for the commissioner’s review and evaluation. If the commissioner determines that such method or protocol is not scientifically valid and defensible, or not of a sufficient level of precision, accuracy, and sensitivity to support the intended use of the data, the commissioner shall identify in writing the reasons for such conclusions and such data shall not be relied upon to demonstrate compliance with the RBCRs.

   3. (2) Laboratory Reporting Limit Requirements The laboratory reporting limit for the analysis of all samples used to comply with the RBCRs shall:

      1. (A) Be established at a concentration which is less than the applicable criteria, unless matrix interference or instrument limitations cannot be overcome by taking the additional actions listed in subdivisions (3) and (4) of this subsection;
      2. (B) Not be artificially raised or lowered; and(C) (i) Be equivalent to the concentration of the lowest standard used to calibrate the instrument actually analyzing a sample, provided such instrument has been calibrated in accordance with a method specified in an RCP or otherwise approved by the commissioner after consultation with the Commissioner of Public Health; or(ii) Be equivalent to the concentration of a low-level reporting standard, as specified in an RCP or otherwise approved by the commissioner after consultation with the Commissioner of Public Health.

   4. (3) Matrix Interference (A) When analyzing a sample, if due to matrix interference the laboratory reporting limit for a substance is greater than the applicable RBCR criteria for such substance, additional procedures, including, but not limited to, sample preparation procedures or alternative analytical methods shall be evaluated to determine whether the use of such procedures or methods will enable a laboratory reporting limit equal to or less than the applicable RBCR criteria for such substance to be consistently and accurately achieved.

      1. (B) In the circumstances described in subparagraph (A) of this subdivision, at a minimum, the following procedures or methods shall be evaluated in determining whether a laboratory reporting limit less than or equal to the applicable criteria can be achieved:

10. (i) “Test Methods for Evaluating Solid Waste: Physical/Chemical Methods.” SW-846, U.S. Environmental Protection Agency, Office of Solid Waste, Washington D.C. 20460; or(ii) Other analytical methods or procedures either approved in writing by EPA or, after consultation with the Commissioner of Public Health, approved in writing by the commissioner.

    1. (C) (i) If pursuant to subparagraph (B) of this subdivision, a procedure or method is identified that will consistently and accurately achieve a laboratory reporting limit equal to or less than the applicable criteria, the sample shall be re-analyzed for the subject substance using such procedure or method.

       1. (ii) If after re-analysis the matrix interference is overcome and the lowest laboratory reporting limit for a substance that can be consistently and accurately achieved is equal to or less than the applicable criteria, the analytical results from such re-analysis can be used for the purpose of determining compliance with the RBCRs.

    2. (D) (i) If despite taking the actions to overcome matrix interference specified in subparagraphs (B) and (C) of this subdivision, a laboratory reporting limit less than or equal to the applicable criteria cannot be consistently and accurately achieved, a report detailing the measures taken to overcome such matrix interference shall be submitted in writing to the commissioner. This report shall include, at a minimum, a description of the measures taken under subparagraphs (B) and (C) of this subdivision as well as the lowest achievable laboratory reporting limit consistently and accurately achievable under subparagraph (C)(i) of this subdivision.

       1. (ii) The commissioner shall use the report submitted pursuant to clause (i) of this subparagraph to determine the lowest laboratory reporting limit for such substance that can be consistently and accurately achieved. If the commissioner determines that such laboratory reporting limit is still greater than the applicable criteria, the commissioner may determine that compliance with the RBCRs will be achieved when such laboratory substance has been remediated to such reporting limit. Any such determination by the commissioner shall be in writing and shall include the reasons for such determination.

    3. (4) Instrument Limitations (A) When analyzing a sample, if due to instrument limitations the laboratory reporting limit for a substance is greater than the applicable RBCR criteria for such substance, alternative analytical methods or alternative instrumentation shall be evaluated to determine whether the use of such procedures or methods will enable a laboratory reporting limit equal to or less than the applicable criteria for such substance to be consistently and accurately achieved.

       1. (B) In the circumstances described in subparagraph (A) of this subdivision, at a minimum, the following procedures or methods shall be evaluated in determining whether a laboratory reporting limit less than or equal to the applicable criteria can be achieved:

11. (i) “Test Methods for Evaluating Solid Waste: Physical/Chemical Methods.” SW-846, U.S. Environmental Protection Agency, Office of Solid Waste, Washington D.C. 20460; or(ii) Other analytical methods or instruments either approved in writing by EPA or, after consultation with the Commissioner of Public Health, approved in writing by the commissioner.

    1. (C) (i) If pursuant to subparagraph (B) of this subdivision, a method or instrument is identified that will consistently and accurately achieve a laboratory reporting limit equal to or less than the applicable criteria, the sample shall be re-analyzed for the subject substance using such method or instrument.

       1. (ii) If after re-analysis the instrument limitation is overcome and the lowest laboratory reporting limit for a substance that can be consistently and accurately achieved is equal to or less than the applicable criteria, the analytical results from such re-analysis can be used for the purpose of determining compliance with the RBCRs.

    2. (D) (i) If despite taking the actions to overcome instrument limitations specified in subparagraphs (B) and (C) of this subdivision, a laboratory reporting limit less than or equal to the applicable criteria cannot be consistently and accurately achieved, a report detailing the measures taken to overcome such instrument limitations shall be submitted in writing to the commissioner. This report shall include, at a minimum, a description of the measures taken under subparagraphs (B) and (C) of this subdivision as well as the lowest achievable laboratory reporting limit consistently and accurately achievable under subparagraph (C)(i) of this subdivision.

       1. (ii) The commissioner shall use the report submitted pursuant to clause (i) of this subparagraph to determine the lowest laboratory reporting limit for such substance that can be consistently and accurately achieved. If the commissioner determines that such laboratory reporting limit is still greater than the applicable criteria, the commissioner may determine that compliance with the RBCRs will be achieved when such substance has been remediated to such laboratory reporting limit. Any such determination by the commissioner shall be in writing and shall include the reasons for such determination.

12. (e) Significant Existing Releases For the purposes of the RBCRs, only the following existing releases are determined to be significant existing releases:

    1. (1) a release that has caused or is causing contamination of a public or private drinking water well;
    2. (2) a release of a substance for which a groundwater protection criteria has been specified that has caused or is causing contamination of groundwater within 500 feet of a private or public drinking water well at a concentration greater than the groundwater protection criteria;
    3. (3) a release discovered in soil within 2 feet of the ground surface that contains a substance at concentrations at or above 30 times the industrial/commercial direct exposure criterion for such substance if the parcel is in industrial or commercial use, or at or above 15 times the industrial/commercial direct exposure criterion for antimony, arsenic, barium, beryllium, cadmium, chromium, copper, cyanide, lead, mercury, nickel, selenium, silver, thallium, vanadium, zinc or polychorinated biphenyls, excluding arsenic or lead from the lawful application of pesticides, if the parcel is in industrial or commercial use and such soil pollution is not more than 300 feet from any residence, school, park, playground or daycare facility, or at or above 15 times the residential direct exposure criterion if the parcel is in residential use;
    4. (4) a release of volatile organic substances or volatile petroleum substances to groundwater that has caused or is causing groundwater within 15 feet of an industrial or commercial building to be contaminated with a volatile organic substance at a concentration at or above 10 times the industrial/commercial volatilization criterion for groundwater for such substance or, if such contamination is within 15 feet of a residential building, at a concentration at or above 10 times the residential volatilization criterion;
    5. (5) a release of a substance at a concentration of greater than 10 times the surface-water protection criteria for such substance, or of a non-aqueous phase liquid, to groundwater within 250 feet of surface water unless data exists to demonstrate that such concentrations decrease below such levels closer to surface water.

13. (f) Criteria and Land Uses (1) When determining the current use of land, all current uses on the parcel impacted by a release, including accessory uses of land, shall be considered. If any use of a parcel, or any portion of the parcel, is for residential activity, the current use of the parcel shall be residential.

    1. (2) When determining the applicable direct exposure and volatilization criteria for remediation, residential criteria shall be considered applicable unless use of a parcel is restricted by an EUR or the parcel is subject to a permit by rule.

14. (g) Issuing Permits to Permitted Environmental Professionals (1) In determining whether the commissioner is satisfied that issuing a permit pursuant to section 22a-454 of the Connecticut General Statutes to a person to act as a permitted environmental professional will not result in pollution, contamination, emergency or the violation of the RBCRs or a violation of any regulation adopted under sections 22a-30, 22a-39, 22a-116, 22a-347, 22a-377, 22a-430, 22a-449, 22a-451 and 22a-462 of the Connecticut General Statutes, the commissioner shall consider:

    1. (A) Such person’s training and education;
    2. (B) The duration and nature of such person’s professional experience; and(C) Any credentials or licenses held by such person.
    3. (2) As part of an application submitted pursuant to section 22a-454 of the Connecticut General Statutes, the commissioner may request any information necessary to comply with the requirements of this subsection.
    4. (3) No permit authorizing a person to act as a PEP shall be renewed if the commissioner determines that the activities of the permittee have resulted or will result in pollution, contamination, emergency, or a violation of the RBCRs. If the activities of a PEP result in pollution, contamination, emergency or a violation of the RBCRs, the commissioner may take any applicable enforcement action authorized by section 22a-134ss of the Connecticut General Statutes.

15. (h) Maintaining a Release (1) For the purposes of the RBCRs, a person shall be maintaining a release when, regardless of fault for the creation of such release, such person:

    1. (A) Owns a parcel of land on or under which such release, or a portion of such release, is located; or(B) Has the right to possess a parcel of land, or the portion of a parcel of land, where such release is located, except that if any person with the right to possess a parcel or portion of a parcel obtains knowledge of a release on the parcel or portion of a parcel they possess, such person shall not be determined to be maintaining such release if such person has notified the owner of the parcel of such release and such release has been reported to the department if such release is required to be reported pursuant to section 22a-134tt-3 of the RBCRs.
    2. (2) A release may be maintained by one or more persons. If more than one person is maintaining a release in violation of the provisions of chapter 445b of the Connecticut General Statutes or the RBCRs, each person shall be jointly and severally liable for compliance with the RBCRs, pursuant to section 22a-134ss(b) of the Connecticut General Statutes.
    3. (3) Any person maintaining a release that has migrated on or under the parcel or portion of a parcel owned or possessed by such person from a source on a different parcel may satisfy the cleanup standards sections of the RBCRs pursuant to section 22a-134tt-7(e) of the RBCRs.
    4. (4) A person shall not be considered to be maintaining releases on a parcel after such person no longer owns or has the right to possess such parcel or a portion of such parcel. If a person was maintaining a release in violation of the provisions of chapter 445b of the Connecticut General Statutes or the RBCRs, the commissioner may take enforcement action against such person, including those actions specified in section 22a-134ss, even if such person no longer owns or has the right to possess a parcel or portion of a parcel.
    5. (5) A lender shall not be considered to be maintaining a release if such lender is exempt from liability pursuant to section 22a-452f of the Connecticut General Statutes.
16. (i) Residential Exemption, Categorical Exemptions, and Lower Bounds (1) Discovery of Existing Releases on Parcels Used for Residential Activity (A) Notwithstanding the requirements of the RBCRs, an existing release shall not be determined to be discovered if:

17. (i) The release area is located on a parcel used only for residential activity;

    1. (ii) The person who obtains knowledge of the release is an owner of such parcel;
    2. (iii) The release is not actually known to impact any other parcel under different ownership;
    3. (iv) The person who obtains knowledge of the release is an occupant of a single family home on such parcel; and(v) The release is not a significant existing release.

    4. (2) Discovery of PFAS or road salt in a public or private drinking water supply (A) Notwithstanding the requirements of the RBCRs, if an existing release of PFAS or chloride-based, inorganic salt is discovered in a public or private drinking water supply, including but not limited to a public or private drinking water supply well, by the person who owns or operates such drinking water supply:

       1. (i) such release shall not be a significant existing release, and immediate action shall not be required; and(ii) provided such release is reported to the commissioner pursuant to the process specified in section 22a-134tt-3 of the RBCRs not more than 3 days following the first discovery of such release, the person who owns or operates such drinking water supply shall not be required to take any other action or pay any fee required by the RBCRs, except if the commissioner determines that such person created or maintained a source of PFAS or salt pursuant to subparagraph (B) of this subdivision.
       2. (B) The commissioner may investigate any release reported pursuant to subparagraph (A) of this subdivision, and if the commissioner identifies the source of such release and the creator or maintainer of such source, the commissioner shall notify such creator or maintainer in writing and such source shall be considered to be discovered for the purposes of section 22a-134tt-2 of the RBCRs, and subject to the requirements of the RBCRs.
       3. (C) If the commissioner identifies the source of such release, the commissioner may issue an order, including an order pursuant to sections 22a-134ss or 22a-471 of the Connecticut General Statutes, to each person who created or is maintaining such source to remediate the source of such release and to require that potable drinking water be provided to all persons affected by such release.

    5. (3) Discovery of PFAS in the land and waters of the state (A) Notwithstanding any other requirements of the RBCRs, an existing release of PFAS discovered in the land and waters of the state, except in a public or private drinking water supply, shall be subject to the requirements of the RBCRs only when:

       1. (i) Such release is discovered at concentrations that indicate that PFAS is not present solely due to atmospheric deposition or the use of consumer products for their intended purpose; and(ii) It can be reasonably expected that the source of such release is or was located on the parcel where such release is discovered or another parcel that is or was owned or operated by the creator of such release;
       2. (B) Any person claiming an exemption from the requirements of the RBCRs pursuant to this subdivision for a release located on a parcel that is or has been used for an industrial/commercial activity shall report the first discovery of such release to the commissioner not more than 365 days after it is discovered, pursuant to section 22a-134tt-3 of the RBCRs.
       3. (C) For the purposes of subparagraph (A) of this paragraph, if PFAS is discovered on a parcel that is or has been used for industrial or commercial purposes known or suspected to use PFAS in its operations, there shall be a reasonable expectation that the source of such release is or was located on such parcel.

    6. (4) Incidental Releases (A) Notwithstanding the requirements of the RBCRs, the presence of the following shall not be determined to be a release:

       1. (i) Trihalomethanes in groundwater reasonably believed to be attributable to naturally-occurring ecological processes or leakage or discharges from a public water supply system;
       2. (ii) The byproducts of the combustion of wood or charcoal reasonably believed to have been used for a residential or recreational purpose;
       3. (iii) Substances resulting or emanating from a consolidated bituminous concrete surface, provided such substance is from an incidental source, as such term is described in section 22a-134tt-9(b)(5)(B) of the RBCRs;
       4. (iv) Substances resulting or emanating from utility poles or landscaping timbers still serving their original intended use; and(v) Substances present due to authorizations issued pursuant to title 22a of the Connecticut General Statutes or due to automotive exhaust or the application of fertilizer or pesticides consistent with their labeling.
       5. (B) If the laboratory analysis of a soil sample identifies the presence of a substance, other than a volatile organic substance or PFAS, at concentrations less than or equal to 25 percent of the applicable criterion specified in sections 22a-134tt-app2 or 22a-134tt-app3 of the RBCRs or a calculated additional polluting substances criterion for such substance in soil, the discovery of such release shall be considered incidental and not subject to any requirements of the RBCRs.
       6. (C) If the laboratory analysis of a soil sample identifies the presence of a substance, other than a volatile organic substance or PFAS, at concentrations less than or equal to 50 percent of the applicable criterion specified in section 22a-134tt-app2 or 22a-134tt-app3 of the RBCRs or a calculated additional polluting substances criterion for such substance in soil, the discovery of such release shall be considered incidental and not subject to any requirements of the RBCRs, provided that:

18. (i) The source of such release is known, and:

    1. (I) 2 additional soil samples are collected, 1 at the approximate location of the source of such release and 1 at a reasonable distance further away from the source of such release as determined by an environmental professional when considering soil type, grade, and the substance identified, and the laboratory analysis of such samples indicates that the concentration of such substance is decreasing away from the source; and(II) Multiple lines of evidence indicate that the substance identified is reasonably likely to be the highest concentration of such substance present in soil as a result of such release; or(ii) The results of laboratory analysis of 5 soil samples, consisting of 3 additional soil samples, each collected at the same depth at a lateral distance of approximately 5 feet from the original sample location, 1 additional soil sample collected not more than 5 feet above the original sample location, and 1 additional soil sample collected at a depth of not more than 5 feet below the original sample location, demonstrate that such substance is not present in soil at the sampling locations, or is present only at concentrations less than or equal to those specified in subparagraph (C) of this subsection.

    2. (5) Notwithstanding section 22a-134tt-1(h) of the RBCRs, no person responsible for the maintenance of a public roadway shall be determined to be maintaining an incidental public roadway release on, under, or within any right of way that contains a public roadway for which such person is responsible provided that:

       1. (A) Any excavated soil impacted by an incidental public roadway release is:

19. (i) Reused pursuant to section 22a-134tt-9(h) of the RBCRs;

    1. (ii) Properly disposed; or(iii) Such soil is:

    2. (I) Reused in the same right of way from which it was excavated;

       1. (II) Reused in a location impacted by the same release, or an existing release of the same substances; and(III) If such soil contains volatile organic substances at concentrations greater than the applicable direct exposure criteria, such soil is 30 feet or more from a building and is reused under concrete or bituminous concrete; and(B) if such incidental public roadway release is a release of chloride-based, inorganic salt and such release has impacted a public or private drinking water supply, a safe drinking water supply is provided by the creator or maintainer of the release to each person served by such well.

    3. (6) Notwithstanding section 22a-134tt-1(h) of the RBCRs, no public utility as defined in section 16-345 of the Connecticut General Statutes or person responsible for the maintenance of a public roadway shall be determined to be maintaining a release discovered as the result of sampling of groundwater when:

       1. (A) The provision of public utility service or maintenance of the public roadway requires dewatering of shallow groundwater for the purposes of facilitating excavation;
       2. (B) Such release is not a significant existing release;
       3. (C) Any required permits for such dewatering activities are obtained; and(D) Groundwater is properly containerized, disposed or treated as required by such permits.
    4. (7) No provision of this subsection shall relieve any person of the requirement to comply with all federal, state, and local requirements, including, but not limited to, 40 CFR 761, all permits, and other required authorizations.

(Effective March 1, 2026)