N.H. Code Admin. R. Env-Wq 402.251

Current through Register No. 25, June 20, 2024

Section Env-Wq 402.251 - Treatment for Excess 1,4-Dioxane and Certain Per- and Polyfluoroalkyl Substances in Wastewater Discharged to Groundwater

(a) If the level of any of the contaminants identified in Env-Dw 402.24(f), Table 402-2, in treated wastewater to be discharged to groundwater exceeds the maximum concentration established in Table 402-2 or if the level of any of the contaminants identified in Env-Dw 402.24(f), Table 402-2, in the groundwater at the perimeter of or outside the groundwater discharge zone exceeds the applicable ambient groundwater quality standard (AGQS) established in Env-Or 603, the facility discharging the wastewater shall:

(1) If the testing done pursuant to Env-Wq 402.25(a)(2) does not show the presence of any of the contaminants identified in Env-Dw 402.24(f), Table 402-2, in a private or public drinking water supply well at a concentration that exceeds the applicable AGQS, either:

a.Treat the wastewater effluent using best available technology (BAT); or

b.Implement an investigation and corrective action program (I&CA program) as described in (c) or (d), below, as applicable, to identify, assess, and address the potential source(s) of the contaminant(s); or

(2) If the testing done pursuant to Env-Wq 402.25(a)(2) shows the presence of any of the contaminants identified in Env-Dw 402.24(f), Table 402-2 in a private or public drinking water supply well at a concentration that exceeds the applicable AGQS and the department determines that it is more likely than not that the permitted wastewater discharge is the source of the contaminant(s), implement the response described in (1)a. or b., above, and (e), below.

(b) Within 90 days of initiating the implementation of the response, the facility shall submit to the department a report of the response implemented that describes all investigative actions taken, the nature and date of each corrective action taken, and the results as demonstrated by sampling of the treated wastewater.

(c) If the permittee is a public wastewater collection and treatment system, the I&CA program required by (a)(2), above, shall include the following:

(1) Assessment of each facility that discharges non-domestic wastewater to the wastewater system;

(2) Sampling within the wastewater system or at facilities connected to the wastewater system to evaluate potential sources of the contaminant(s); and

(3) Modification of operations at facilities discharging non-domestic wastewater as needed to reduce or eliminate sources that cause or contribute to elevated concentrations of the contaminant(s).

(d) If the permittee is not a public wastewater collection and treatment system, the I&CA program required by (a)(2), above, shall include the following:

(1) A review of the materials used in the facility to identify potential sources of the contaminant(s);

(2) Sampling of the materials used in the facility to evaluate potential sources of the contaminant(s); and

(3) Modification of facility operations, such as installing treatment systems for wastewater or replacing the materials that are causing or contributing to elevated concentrations of the contaminant(s) to the extent practicable.

(e) If required by (a)(2), above, the permittee shall:

(1) Expand the testing of public and private drinking water wells beyond 1,000 feet as necessary to determine the extent of the exceedance of the applicable AGQS in drinking water supplies; and

(2) Within 21 days of receiving the test results obtained pursuant to (1), above, submit a proposed response plan to the department that evaluates the relative costs and benefits of:

a.Installing treatment to remove the contaminant(s) from the water supplied from the well; or

b.Providing alternate water to those served by the drinking water supply by:

1.Supplying bottled water as an interim mitigation measure until a long-term water supply alternative is provided; and

2.Providing a long-term alternative water supply by:

(i) Installing, testing, and maintaining a point-of-entry water treatment system at each structure served; or

(ii) Connecting each structure served to a public water system.

(f) The response plan submitted pursuant to (e)(2), above, shall include:

(1) A recommendation for providing alternate water; and

(2) A schedule for implementing the response plan.

(g) The department shall:

(1) Approve the plan, including the schedule, if it determines that the plan is adequate to protect public health; and

(2) Notify the permittee of its determination in writing, provided that if the plan is not approved the department shall identify the reason(s) why.

(h) The permittee shall implement the response plan in accordance with the schedule approved by the department.

N.H. Code Admin. R. Env-Wq 402.251

Derived from Volume XXXVIII Number 28, Filed July 12, 2018, Proposed by #12553, Effective 9/1/2018, Expires 9/1/2028.

Amended by Volume XXXIX Number 32, Filed August 8, 2019, Proposed by #12836, Effective 9/30/2019, Expires 9/30/2029.