The necessity of providing increased treatment of pollutants and reduction in nutrients discharged from on-site sewage disposal systems in areas designated as nitrogen sensitive areas warrants the imposition of the following nitrogen loading limitations:

1. (1) Public and Private Water Supply Protection Areas. No facility owner for New Construction in Nitrogen Sensitive Areas designated in 310 CMR 15.214(1)(a) shall install a system designed to receive or allow a system to receive more than 440 gallons of design flow per day per acre except as set forth in 310 CMR 15.202 (use of recirculating sand filters), 310 CMR 15.216 (aggregate flows) or 310 CMR 15.217 (enhanced nitrogen removal).

2. (2) Natural Resource Areas. Any system serving New Construction or an existing facility in a Nitrogen Sensitive Area designated pursuant to 310 CMR 15.214(1)(b) on or after July 7, 2023 shall incorporate Best Available Nitrogen Reducing Technology, as follows:

   1. (a) Existing Systems. The owner of a system serving, or approved to serve, an existing facility as of the effective date of the Nitrogen Sensitive Area designation shall upgrade the system pursuant to 310 CMR 15.401 through 15.405 to incorporate the Best Available Nitrogen Reducing Technology within five years of the date on which the Notice of Intent and Application Period ends unless:

      1. 1. Except as otherwise provided in 310 CMR 15.215(2)(c)4. and 314 CMR 21.12(5), a Notice of Intent, a Watershed Permit application, or a De Minimis Nitrogen Load Exemption application is filed for the area during the Notice of Intent and Application Period pursuant to 310 CMR 15.215(2)(c), 314 CMR 21.03: Application for a Watershed Permit, or 314 CMR 21.12: De Minimis Nitrogen Load Exemption, respectively; or
      2. 2. The Nitrogen Sensitive Area is subject to a De Minimis Nitrogen Load Exemption and the facility is within the area covered by the exemption; or

      3. 3. The Nitrogen Sensitive Area is subject to a Watershed Permit, the facility is within the area covered by the permit, and:

         1. a. The Watershed Permit to which the Nitrogen Sensitive Area is subject specifies that the five-year upgrade requirement has been suspended on the basis of permit conditions that ensure at least equivalent nitrogen reductions within the schedule included in the Watershed Permit; or, for Watershed Permits issued before promulgation of 314 CMR 21.00: Massachusetts Watershed Permit Regulations, the five-year upgrade requirement is suspended for each permittee's watershed area, unless and until the permit is revoked or terminated, in which case 310 CMR 15.215(2)(d) shall go into effect for each system in the watershed area of each permittee to whom the revocation or termination is applicable; and
         2. b. The watershed permittee(s) is in compliance with the terms and conditions of the permit.

   2. (b) New Construction. Beginning six months after the effective date of the Nitrogen Sensitive Area designation any systems serving New Construction shall incorporate Best Available Nitrogen Reducing Technology. The Department will suspend this requirement only if:

      1. 1. Except as otherwise provided in 310 CMR 15.215(2)(c)4. and 314 CMR 21.12(5), a Notice of Intent, a Watershed Permit application, or a De Minimis Nitrogen Load Exemption application is filed for the area during the Notice of Intent and Application Period pursuant to 310 CMR 15.215(2)(c), 314 CMR 21.03: Application for a Watershed Permit, or 314 CMR 21.12: De Minimis Nitrogen Load Exemption, respectively; or
      2. 2. The Nitrogen Sensitive Area is subject to a De Minimis Nitrogen Load Exemption and the facility is within the area covered by the exemption; or

      3. 3. The Nitrogen Sensitive Area is subject to a Watershed Permit and the New Construction is within the area covered by the permit and:

         1. a. The Watershed Permit to which the Nitrogen Sensitive Area is subject specifies that the Best Available Nitrogen Reducing Technology incorporation requirement has been suspended on the basis of permit conditions that ensure nitrogen reductions will be sufficient to offset future additional nitrogen loads from newly constructed on-site systems; and
         2. b. The watershed permittee(s) is in compliance with the terms and conditions of the Watershed Permit.

   3. (c) Notice of Intent and Application Period.

      1. 1. The filing of an application for a Watershed Permit or a De Minimis Nitrogen Load Exemption or a Notice of Intent to apply for a Watershed Permit during the Notice of Intent and Application Period by a party who could otherwise apply for such permit under 314 CMR 21.00: Massachusetts Watershed Permit Regulations will prevent commencement of the five-year time period in which Title 5 system upgrades would otherwise be required under 310 CMR 15.215(2)(a).
      2. 2. An application for a Watershed Permit or De Minimis Nitrogen Load exemption shall be filed pursuant to 314 CMR 21.03: Application for a Watershed Permit or 21.12: De Minimis Nitrogen Load Exemption, respectively. A Notice of Intent shall be filed on a form provided by the Department and shall include a proposed schedule with sufficient milestones to be approved by the Department for the filing of a Watershed Permit application and issuance of the permit as soon as practicable but no later than seven years from the applicable Nitrogen Sensitive Area designation under 310 CMR 15.214(1)(b).
      3. 3. Within 28 days of filing a Notice of Intent, a Watershed Permit application, or De Minimis Nitrogen Load Exemption application, the party who filed such notice or application must publish notice of its filing and any suspension of the Title 5 upgrade and New Construction requirements under 310 CMR 15.215(2)(a) and (b): in the forthcoming Environmental Monitor; on the party's official website; in the town hall where similar notices are published; and in a local or regional newspaper with the largest readership distribution within the area that may be affected by the Title 5 upgrade and New Construction requirements in 310 CMR 15.215(2)(a) and (b). In municipalities with Environmental Justice Populations where the preceding method for publishing public notice does not specifically serve the Environmental Justice Population(s), the party who filed the Notice of Intent or Watershed Permit application must publish the preceding notice in at least one additional news organization that primarily serves the Environmental Justice Population(s) within the area that may be affected by the designation. The public notice shall be translated into other languages that are prevalent in areas with persons of limited English proficiency.
      4. 4. A party's failure to comply with deadlines in a Watershed Permit application schedule in a Notice of Intent approved under 310 CMR 15.215(2)(c)2. will commence the New Construction requirements and five-year time period for mandatory upgrades to existing systems under 310 CMR 15.215(2)(a) and (b) upon issuance of notice from the Department to the noncompliant party. Within 28 days of issuing that notice to the noncompliant party, the Department shall publish notice in accordance with the notice publication provisions in 310 CMR 15.215(2)(c)3. that the Title 5 upgrade and New Construction requirements under 310 CMR 15.215(2)(a) and (b) have been invoked.

   4. (d) Termination or Revocation of Watershed Permit or De Minimis Nitrogen Load Exemption. If a De Minimis Nitrogen Load Exemption or a Watershed Permit is terminated or revoked pursuant to 314 CMR 21.00: Massachusetts Watershed Permit Regulations for one or more permittees to the permit, any owner of an existing system or a system to serve New Construction in the designated Nitrogen Sensitive Area pertaining either to each permittee whose permit status is terminated or revoked or to the area that was covered by the De Minimis Nitrogen Load Exemption, as applicable, shall incorporate Best Available Nitrogen Reducing Technology, as follows:

      1. 1. For existing systems or those with a Disposal System Construction Permit for installation as of the date of the Watershed Permit or De Minimis Nitrogen Load Exemption termination or revocation, within five years of the date when the Notice of Intent and Application Period would have otherwise ended by its own terms or within two years of the date of termination or revocation of the Watershed Permit or De Minimis Nitrogen Load Exemption (as applicable), whichever is longer.
      2. 2. New systems installed after the effective date of the Watershed Permit or De Minimis Nitrogen Load Exemption termination or revocation shall incorporate Best Available Nitrogen Reducing Technology.
   5. (e) Notwithstanding 310 CMR 15.215(2)(a) through (d), the Department may extend any time limit contained in 310 CMR 15.215 for good cause including, but not limited to, an insufficient supply of necessary equipment or materials or unavailability of contractors.
   6. (f) Facility owners that install Best Available Nitrogen Reducing Technology pursuant to 310 CMR 15.215(2) shall not be required to upgrade to subsequent Best Available Nitrogen Reducing Technology unless the Approving Authority determines that: the system has failed and is required to be upgraded; there is an alteration to or change in use of the facility that is determined to be New Construction; or the system is failing to protect the public health, safety, and the environment.
   7. (g) The Department will maintain and publish a list on its website of Best Available Nitrogen Reducing Technologies and nitrogen reducing technologies that have received general, provisional, or piloting approval pursuant to 310 CMR 15.285 through 15.288. The Department may allow the use of technologies that do not meet the Best Available Nitrogen Reducing Technology definition in the event of significant supply or market limitations. The Department may prohibit the use of a technology as Best Available Nitrogen Reducing Technology based on a technology's noncompliance with the performance standards established in the technology's approval.
   8. (h) Facility owners that upgraded their system within ten years prior to the effective date of the Nitrogen Sensitive Area designation with Department-approved nitrogen removing technology are exempt from the individual system upgrade requirements in 310 CMR 15.215(2)(a) unless the Approving Authority determines that: the system has failed and is required to be upgraded; there is an alteration to or change in use of the facility that is determined to be New Construction; or the system is failing to protect the public health, safety, and the environment.
   9. (i) A facility owner of a system(s), which pursuant to 310 CMR 15.006 serves an existing facility with a design flow of 10,000 gpd or greater but less than 15,000 gpd, shall upgrade the system(s) pursuant to 310 CMR 15.304 when the facility is in a location designated as a Nitrogen Sensitive Area pursuant to 310 CMR 15.214.
3. (3) The owner of a system serving New Construction in a Nitrogen Sensitive Area designated in both 310 CMR 15.214(1)(a) and (1)(b) shall comply with the requirements of 310 CMR 15.215(2).
4. (4) The owner of a system or proposed system shall ascertain whether the facility is in a designated Nitrogen Sensitive Area. The Department will prepare and make available on the Department’s website maps portraying designated Nitrogen Sensitive Areas within the Commonwealth. Prior to any transfer of title for property where the facility is located, the transferor shall disclose to the transferee and Board of Health whether the facility is subject to an upgrade requiring Best Available Nitrogen Reducing Technology pursuant to 310 CMR 15.215.