Section R18-9-D307. 3.07 General Permit: Tertiary Treatment Wet- lands

A.      A 3.07 General Permit allows constructed wetlands that receive with the intent to treat, discharges of reclaimed water that meet the secondary treatment level requirements specified in R18-9-B204(B)(1).

B.       Notice of Intent to Discharge. In addition to the Notice of Intent to Discharge requirements specified in R18-9-A301(B), an applicant shall submit:

1.        The name and individual permit number of any facility that provides the reclaimed water to the treatment wet- land;

2.        The name and individual permit number of any facility that receives water released from the treatment wetland;

3.        The design of the treatment wetland construction and management project, including information on the quality of the influent, the treatment process, and the expected quality of the wastewater;

4.        A Best Management Practices Plan that includes:

a.         A site plan showing the treatment wetland footprint, point of inflow, stormwater drainage, and placement of vegetation;

b.        A contingency plan to address any problem, includ- ing treatment performance, wash-out, and vegetation die-off;

c.         A management plan for flows into and through the treatment wetland to minimize erosion and damage to vegetation;

d.        A description of the measures for restricting access to the treatment wetlands by the public;

e.         A management plan for vector control; and

f.         A plan or criteria for enhancing or supplementing treatment wetland vegetation.

C.      Design requirements. An applicant shall:

1.        Release water from the treatment wetland under an indi- vidual permit and an AZPDES permit, if required. The applicant shall release water from the treatment wetland only to a direct reuse site if the site is permitted to receive reclaimed water of the quality generated under the indi- vidual permit specified in subsection (B)(1);

2.        Construct and locate the treatment wetland so that it:

a.         Maintains physical integrity during a 100-year, 24- hour storm event; and

b.        Operates properly during a 25-year, 24-hour storm event;

3.        Ensure that the bottom of the treatment wetland is at least 20 feet above the seasonal high groundwater table;

4.        Maintain a minimum horizontal separation of 100 feet between a water supply well and the maximum wetted area of the treatment wetland;

5.        Maintain the setbacks specified in R18-9-B201(I) for no noise, odor, or aesthetic controls between the property boundary at the site and the maximum wetted area of the treatment wetland;

6.        Fence the treatment wetland area to prevent unauthorized access;

7.        Post signs at points of access stating “CAUTION. THESE WETLANDS CONTAIN RECLAIMED WATER, DO NOT DRINK.” The applicant shall ensure that the signs are in English and Spanish, or in English with inclusion of the international “do not drink” symbol;

8.        Construct the treatment wetland with a liner using low hydraulic conductivity liner, site-specific liner, or both, to achieve a calculated seepage rate of less than 550 gallons per acre per day. The applicant shall:

a.         Ensure that if a synthetic liner is used, such as geomembrane, the liner is underlain by at least 6 inches of prepared and compacted subgrade;

b.        Anchor the liner along the perimeter of the treatment wetland; and

c.         Manage the plants in the treatment wetland to pre- vent species with root penetration that impairs liner performance;

9.        Calculate the size and depth of the treatment wetland so that the rate of flow allows adequate treatment detention time. The applicant shall design the treatment wetland with at least two parallel treatment cells to allow for effi- cient system operation and maintenance;

10.     Ensure that the treatment wetland vegetation includes cat- tails, bulrush, common reed, or other species of plants with high pollutant treatment potential to achieve the intended water quality identified in subsection (B)(3); and

11.     Ensure that construction and operation of the treatment wetlands is consistent with local zoning and land use requirements.

D.      Operational requirements. The permittee shall:

1.        Implement the Best Management Practices Plan approved under subsection (B);

2.        Monitor wastewater leaving the treatment wetland to ensure that discharge water quality meets the expected wastewater quality specified in subsection (B)(3). The permittee shall ensure that analyses of wastewater sam- ples are conducted by a laboratory certified by the Department of Health Services, following the Depart- ment’s Quality Assurance/Quality Control requirements;

3.        Follow the prescribed measures as required in the contin- gency plan under subsection (B)(4)(b) and submit a writ- ten report  to the Department within  five  days if verification sampling demonstrates that an alert level or discharge limit is exceeded;

4.        Inspect the treatment wetlands at least quarterly for bank and liner integrity, erosion evidence, and condition of sig- nage and vegetation, and correct any problem discovered; and

5.        Ensure that the treatment wetland is operated by a certi- fied operator under 18 A.A.C. 5, Article 1.

E.       Recordkeeping. A permittee shall maintain the following information for at least 10 years and make it available to the Department upon request:

1.        Construction drawings and as-built plans, if available; and

2.        A log book or similar documentation to record inspection results, repair and maintenance activities, monitoring results, and facility closure.

F.       Reporting requirements. The permittee shall, by January 30, provide the Department in writing with an annual assessment of the biological condition of the treatment wetland including the volume of inflow to the treatment wetland in the past year.

Historical Note

New Section adopted by final rulemaking at 7 A.A.R. 235, effective January 1, 2001 (Supp. 00-4). Amended by final rulemaking at 11 A.A.R. 4544, effective November 12, 2005 (05-3).