1. (a) Time-frames for Issuance of Approvals by the Commissioner The commissioner shall make best efforts within available resources to process in a timely manner any variance or alternative criteria request pursuant to the cleanup standards sections of the RBCRs. The commissioner shall, upon request, provide estimated time frames for any such review. In establishing estimated time frames pursuant to this subsection, the commissioner shall take into account available resources, the complexity of the request, and the environmental and economic significance of the remediation.

2. (b) Environmental Use Restrictions (1) Whenever an EUR is required under the RBCRs:

   1. (A) An ELUR may always be used; and(B) A NAUL may only be used:

3. (i) Pursuant to section 22a-134tt-9(b)(2) of the RBCRs, provided the subject area is zoned for industrial/commercial use and no holder of an interest in such area, other than the owner of such area, has a right of residential activity or use;

   1. (ii) Pursuant to section 22a-134tt-9(b)(3)(B) of the RBCRs, provided the concentrations of substances in such inaccessible soil do not exceed 10 times the applicable direct exposure criteria;
   2. (iii) Pursuant to section 22a-134tt-9(b)(6) of the RBCRs;
   3. (iv) Pursuant to section 22a-134tt-9(c)(5)(A) of the RBCRs, provided that:
   4. (I) The concentrations of substances in such soil do not exceed 10 times the applicable direct exposure criteria and the applicable pollutant mobility criteria; or(II) The total volume of soil that is environmentally isolated that exceeds 10 times the applicable direct exposure criteria and the applicable pollutant mobility criteria is equal to or less than 10 cubic yards;

4. (v) Pursuant to section 22a-134tt-9(d)(2)(A) of the RBCRs;

   1. (vi) Pursuant to section 22a-134tt-9(f)(1) of the RBCRs;
   2. (vii) Pursuant to section 22a-134tt-9(f)(2)(B) or section 22a-134tt-9(f)(2)(C) of the RBCRs, provided that the concentrations of the substances in polluted soil at the subject area are equal to or less than 10 times the applicable direct exposure criteria;
   3. (viii) Pursuant to section 22a-134tt-10(c)(1) or section 22a-134tt-10(c)(2)(A) of the RBCRs, provided the subject area is zoned for industrial/commercial use and no holder of an interest in such area, other than the owner of such area, has a right of residential activity or use;
   4. (ix) Pursuant to section 22a-134tt-10(c)(2)(B) of the RBCRs;
   5. (x) Pursuant to sections 22a-134tt-10(c)(3), 22a-134tt10(c)(4), and 22a-134tt-10(c)(5) of the RBCRs;
   6. (xi) When an ELUR is required and the parcel on which it is to be recorded is owned by the state of Connecticut or the state of Connecticut purchases a property subject to an existing ELUR, the NAUL shall be approved by the commissioner;
   7. (xii) Pursuant to section 22a-134tt-9(b)(2)(C)of the RBCRs; or(xiii) Pursuant to section 22a-134tt-9(b)(2)(D) of the RBCRs.
   8. (2) Each EUR under the RBCRs shall be subject to and comply with all applicable requirements in section 22a-133o of the Connecticut General Statutes, the EUR regulations and the RBCRs.

   9. (3) If the RBCRs require an EUR:

      1. (A) Such EUR shall be in effect prior to:

5. (i) An LEP’s verification, including an LEP’s interim verification as those terms are defined in sections 22a-134(19), 22a-134(28), and 22a-134pp(9) of the Connecticut General Statutes and section 22a-134tt-1(164) of the RBCRs, including, but not limited to, a verification pursuant to section 22a-134tt-11 of the RBCRs; or(ii) When required by the commissioner, the review and approval of the remediation by the commissioner; or(B) When voluntary remediation is conducted pursuant to section 22a-133y of the Connecticut General Statutes, the documents required to be prepared by sections 22a-133q-2(b) or 22a-133q-3(b) of the EUR regulations, as applicable, shall be submitted as part of the final remedial action report at the time such report is submitted to the commissioner. Upon approval of such report by the commissioner, the EUR shall be executed not later than 36 days after such approval and be put into effect in accordance with the EUR regulations.

   1. (4) An EUR shall only be deemed to be in effect when such EUR is recorded on the land records in compliance with the EUR regulations.
   2. (5) When a remedy is selected under the cleanup standards sections of the RBCRs for which an EUR is required to be in effect for different subject areas on a parcel, a request may be submitted to the commissioner to extend any deadline specified in the cleanup standards sections of the RBCRs to prepare the materials required to obtain and request such EUR. The commissioner may approve or deny in writing such extension request. No request shall be approved unless it is demonstrated to the commissioner’s satisfaction that significant progress has been made to complete the remediation of the parcel and strict adherence to the stated deadline would create an extraordinary hardship.
   3. (6) A single EUR may be used to satisfy the requirements of the cleanup standards sections of the RBCRs for more than one release on a parcel, provided such EUR includes each restriction or obligation specified by the cleanup standards for each release.

6. (c) Financial Assurance (1) A financial assurance shall be required to support an engineered control variance or a technical impracticability variance. Such assurance shall be:

   1. (A) Established and maintained for the duration of the period that the engineered control or technical impracticability variance will be used to achieve compliance with the RBCRs;
   2. (B) Directly available to the commissioner to cover the costs of complying with the variance, including, but not limited to, operation, maintenance, inspection, monitoring, reporting, and other reasonably anticipated repairs and contingencies, in the event that the commissioner determines that such measures have not been performed as required by the RBCRs; and(C) Established in an amount equal to the cost of 20 percent of 30 years of operation, maintenance, inspection, monitoring, reporting, and other reasonably anticipated repairs and contingencies, which amount shall be maintained in effect for as long as the variance is used to achieve compliance with the RBCRs, except this amount may be adjusted in accordance with subdivision (4) of this subsection.

   3. (2) One or more of the following instruments, and no others, shall be used to satisfy the financial assurance requirements of this subsection:

      1. (A) Trust agreement or trust fund;
      2. (B) Irrevocable standby letter of credit;
      3. (C) Payment of funds in cash as directed by the commissioner; or(D) Certificate of insurance.

   4. (3) The wording of any instrument used to satisfy the requirements of this subsection shall be identical to the language prescribed by the commissioner, which language shall be posted on the department’s internet website. In addition, only an entity that satisfies the following requirements, as applicable, may issue an instrument used to satisfy the requirements of this subsection:

      1. (A) Any trustee shall be an entity with authorization to act as a trustee and whose trust operations are regulated and examined by a federal or state agency;
      2. (B) Any surety issuing a bond shall be among those listed as acceptable sureties on federal bonds in Circular 570 of the U.S. Department of Treasury;
      3. (C) Any institution issuing a letter of credit shall be an entity that has the authority to issue letters of credit and whose letter of credit operations are regulated and examined by a federal or state agency; and(D) Any insurer shall be licensed to transact the business of insurance, or eligible to provide insurance as an excess or surplus lines insurer, in one or more states.

   5. (4) The amount of the financial assurance established pursuant to this subsection:

      1. (A) Shall be adjusted for inflation at each 5 year interval from the anniversary date of the establishment of the financial instrument. The adjustment shall be made by using an inflation factor derived from the most recent Implicit Price Deflator for Gross National Product published by the U.S. Department of Commerce in its “Survey of Current Business” and by multiplying the latest adjusted surety estimate for the site by that 5-year inflation factor; and(B) May be adjusted, subject to the discretion and written approval of the commissioner, to reflect any recalculation of the costs of operation, maintenance, inspection, monitoring, reporting, and other reasonably anticipated repairs and contingencies, in current dollars. Any request for an adjustment pursuant to this subparagraph shall be submitted to the commissioner in accordance with section 22a-134tt-1(c) of the RBCRs.

   6. (5) The requirements of this subsection shall not apply when:

      1. (A) The entity responsible for remediation is a municipality, an agency or a political or administrative subdivision of the state or federal government; or(B) The amount established under subdivision (1)(C) of this subsection is less than $10,000, unless the commissioner requires compliance with this subsection as a condition of approving the engineered control or technical impracticability variance.

7. (d) Public Participation (1) Erection of a Sign A sign not less than 6 feet by 4 feet that is clearly visible from the public roadway, and includes the words “ENVIRONMENTAL CLEAN UP IN PROGRESS. FOR FURTHER INFORMATION CONTACT:” and includes a telephone number and an electronic mail address from which any party may obtain additional information about the proposed remediation shall be erected and maintained by the creator or maintainer whenever:

   1. (A) Active remediation of an existing release, including but not limited to excavating, removing or stockpiling soil, is underway on a parcel; or(B) The remediation of an emergent reportable release is underway, and the commissioner has directed in writing that a sign shall be erected and maintained.

   2. (2) Public Notice (A) The creator or maintainer of a release shall provide public notice of remediation for each release assigned to a tier, pursuant to section 22a-134tt-6 of the RBCRs. Public notice may be combined for multiple releases on the same parcel, provided all required information is included for each release. If there are multiple creators or maintainers of a release, only a single notice is required. Such notice shall be provided before the date of tier assignment. Public notice shall be prepared using a form prescribed by the commissioner, and shall include:

      1. (i) The address of the parcel on which remediation will be undertaken or, if no address is available, a description of the location of the parcel relative to the nearest intersection of named streets;
      2. (ii) A brief description of the nature of the release and the substances being remediated;
      3. (iii) An electronic mail and postal mailing address, telephone number, and a point of contact to whom comments regarding the remediation can be submitted and from whom any interested person may obtain additional information about the proposed remediation;
      4. (iv) A statement that public comments may be submitted, via electronic mail or in writing, for 30 days after the date of publication of such notice; and(v) Any other information specified by the commissioner on such form.
      5. (B) Public notice shall be provided by mailing or personally delivering the public notice form to the chief elected municipal official and to the Director of Health of the municipality in which remediation will occur and publishing the information specified on such form in a newspaper having general circulation in the municipality in which the release is located.
      6. (C) There shall be a public comment period on the proposed remediation for 30 days after publication of the newspaper notice required by subdivision (2)(B) of this subdivision. If comments on the proposed remediation are received during the public comment period, no later than 30 days after close of the public comment period, the person responsible for remediation shall submit to the commissioner a written summary of all such comments and a proposed response to each such comment. Based on the summary of comments and proposed responses, the commissioner may:

8. (i) Direct the person responsible for remediation to send the written summary and response document to each person who submitted comments not later than 30 days after the direction is given by the commissioner. If an electronic mail address is known, the summary and response document may be sent to a commenter using electronic mail;

   1. (ii) Revise the written summary and response document and direct the person responsible for remediation to send the written summary and response document, as revised by the commissioner, to each person who submitted comments not later than 30 days after the direction is given by the commissioner. If an electronic mail address is known, the summary and response document as revised by the commissioner may be sent to a commenter using electronic mail; or(iii) Determine that there is substantial public interest in the proposed remediation and direct the person responsible for the remediation to hold a public meeting regarding the proposed remediation. Notice of any such meeting shall be published in a newspaper of substantial circulation in the area of the proposed remediation at least 30 days prior to such meeting. At such meeting all interested persons shall have reasonable opportunity to submit data, views, or arguments orally or in writing. Any such meeting shall not be conducted as, nor be considered to be, a contested case as that term is defined in section 4-166 of the Connecticut General Statutes. After the public meeting, the person responsible for remediation shall comply with subparagraph (C) of this subdivision and, except for this clause, the commissioner may then take actions specified under this subparagraph. Not later than 30 days after a public meeting held in accordance with subparagraph (C) of this subdivision, the person responsible for remediation shall provide to the commissioner a written summary of and response to any comments received during the public meeting and the commissioner may then take any of the actions in subclauses (i) or (ii) of this subparagraph.

9. (e) Conditional Exemption for Existing Releases That Have Migrated (1) Whenever characterization conducted pursuant to section 22a-134tt-4 of the RBCRs demonstrates that any person is maintaining a release in the land and waters of the state only because a portion of such release has migrated onto a parcel owned or in the possession of such person, such person may satisfy all obligations imposed by the RBCRs if such person:

   1. (A) Demonstrates that:

10. (i) Such person neither created the release nor owns or is in possession of the parcel from which such release is or was migrating;

    1. (ii) Such substances are not already present in the land and waters of the state at the release area owned or possessed by such person because of a release at such parcel; and(iii) On the parcel owned or in possession of such person, all exposure pathways to drinking water supply wells, direct exposure to impacted soil, and from volatilization of impacted soil or groundwater into buildings from such release have been broken or mitigated to the extent reasonably necessary to protect human health. The direct exposure pathway to impacted soil shall be determined to be broken if the immediate action transition-point specified at section 22a-134tt-5(h)(2)(C) of the RCBRs has been achieved; and(B) Reports such release, if reporting is required pursuant to section 22a-134tt-3 of the RBCRs, in the time provided for the submission of such a report and takes any immediate action required by section 22a-134tt-5 of the RBCRs for the portion of the release on the parcel owned or in the possession of such person;
    2. (C) Prepares and submits a release remediation closure report pursuant to section 22a-134tt-12 of the RBCRs, provided that only the characterization information necessary to make the demonstrations required by subparagraph (A) of this subdivision shall be included in such report; and(D) Agrees to provide reasonable access to the creator of such release or the maintainer of the source of such release for the purpose of complying with the RBCRs.

    3. (2) Whenever characterization conducted pursuant to section 22a-134tt-4 of the RBCRs demonstrates that a person is maintaining a release to groundwater and that the substances present in such release have co-mingled with the same substances from a different release that has migrated from a parcel not owned or in the possession of such person, such person shall comply with the RBCRs, except that if such person did not create and is not maintaining the source of both releases, such person may close the release that they created or are maintaining if:

       1. (A) On the parcel owned or in possession of such person, all exposure pathways from each comingled release to drinking water supply wells and from volatilization into buildings have been broken or mitigated to the extent reasonably necessary to protect human health;
       2. (B) Such person prepares and submits a release-remediation closure report pursuant to section 22a-134tt-12 of the RBCRs demonstrating that closure characterization has been completed for the release created or maintained by such person and the portion of the release that has migrated onto property owned or in the possession of such person pursuant to section 22a-134tt-4 of the RBCRs and that concentrations of such substances do not exceed the concentrations of such substance at the boundary of the parcel onto which a release has migrated; and(C) Such person agrees to provide reasonable access to the creator of such release or the maintainer of the source of such release for the purpose of complying with the RBCRs.
    4. (3) The provisions of this subsection do not apply to any substances other than those substances that have migrated or are migrating from one parcel to another, to substances on a parcel that are comingled with a release of the same substances that has migrated onto such parcel, or substances present as a result of natural degradation transformations of such substances.
    5. (4) No provision of this subsection shall affect the ability of any person to seek recovery of costs incurred by such person pursuant to section 22a-452 of the Connecticut General Statutes or of the commissioner to recover costs incurred in accordance with section 22a-451 of the Connecticut General Statutes.
    6. (5) For the purposes of this subsection, reasonable access to an area used as a public roadway includes access provided at the time the next scheduled roadway improvement project is conducted or the creator of such release or the maintainer of the source of the release provides payment to the person responsible for maintaining the public roadway if the person responsible for maintaining the public roadway agrees to accept the payment and remediate the release as a part of the next scheduled roadway improvement project.
11. (f) Other Requirements All remediation undertaken to satisfy the RBCRs shall be conducted in accordance with all federal, state, and local requirements, including, but not limited to, 40 CFR 761, all permits, and other required authorizations. Nothing in this subsection shall be construed as requiring any further remediation of any release which has been remediated and which remediation has been approved in writing by the commissioner, unless the commissioner takes action to require such remediation pursuant to any section of Chapter 446k of the Connecticut General Statutes.

12. (g) Applicability of Remediation to Volatilization Criteria (1) Provided the requirements of subdivision (2) of this subsection are satisfied, notwithstanding sections 22a-134tt-10(a) and 22a-134tt-10(c) of the RBCRs, volatile organic substances in groundwater may be remediated to:

    1. (A) No more than 15 feet from the ground surface and no more than 15 feet from the lowest portion of a building under which groundwater is polluted with such substances; and(B) The applicable groundwater volatilization criteria listed in the following table. Volatile SubstanceResidential Volatilization Criteria for Groundwater in µg/L (ppb)Industrial/Commercial Volatilization Criteria for Groundwater in µg/L (ppb)Acetone50,00050,000Benzene215530Bromoform9203,8002-Butanone (MEK)50,00050,000Carbon Tetrachloride1640Chlorobenzene1,8006,150Chloroform2877101,2-Dichlorobenzene30,50050,0001,3-Dichlorobenzene24,20050,0001,4-Dichlorobenzene50,00050,0001,1-Dichloroethane34,60050,0001,2-Dichloroethane21901,1-Dichloroethylene161,2-Dichloropropane14601,3-Dichloropropene625Ethyl benzene50,00050,000Ethylene dibromide (EDB)416Methyl-tert-butyl-ether50,00050,000Methyl isobutyl ketone50,00050,000Methylene chloride50,00050,000Styrene5802,0651,1,1,2-Tetrachloroethane12501,1,2,2-Tetrachloroethane23100Tetrachloroethylene1,5003,820Toluene23,50050,0001,1,1-Trichloroethane20,40050,0001,1,2-Trichloroethane8,00019,600Trichloroethylene219540Vinyl chloride22Xylenes21,30050,000(2) Compliance with subparagraphs (A) to (D) of this subdivision is required in order to be eligible to use the remediation standards set forth in subdivision (1) of this subsection.

       1. (A) Prior to February 16, 2021:

13. (i) Remediation of such volatile organic substances shall have already been initiated or an LEP shall have documented in a remedial action plan submitted to the commissioner such LEP’s determination that no remediation of such substances is required; and(ii) If required, public notice of such remediation shall have been published, pursuant to subsection (d) of this section or any provision of the Connecticut General Statutes;

    1. (B) On or before February 16, 2023, remediation of such volatile organic substances shall have been completed and approved by the commissioner, or completed sufficient to support an LEP’s verification, as that term is defined in section 22a-133v-1(dd) of the Regulations of Connecticut State Agencies;
    2. (C) Compliance with all other requirements in the RBCRs regarding volatile organic substances in groundwater shall have been achieved; and(D) Documentation demonstrating compliance with this subsection is submitted to the commissioner by the earliest of the following dates:

14. (i) The applicable deadline set forth in section 22a-134a(g)(1)(B) or section 22a- 134a(g)(1)(C) of the Connecticut General Statutes;

    1. (ii) The deadline set forth in any order issued by the commissioner;
    2. (iii) The deadline set forth in any judgment issued by a court; or(iv) February 16, 2026.
    3. (3) In the event the requirements of subdivision (2) of this subsection are not complied with, volatile organic substances in groundwater shall be remediated to the standards set forth in Appendix 6 of the RBCRs, and not those in subdivision (1) of this subsection.

(Effective March 1, 2026)