Ariz. Admin. Code § 18-9-A317

Current through Register Vol. 30, No. 25, June 21, 2024

Section R18-9-A317 - Nitrogen Management Area

A. The Director may designate a new Nitrogen Management Area to control groundwater pollution by sources of nitrogen regulated by Title 49, Chapter 2, Article 3 of the Arizona Revised Statutes and not covered under an individual permit, modify the boundaries or requirements of a Nitrogen Management Area, or rescind designation of a Nitrogen Management Area.

1. If existing conditions or trends in nitrogen loading to an aquifer will cause or contribute to an exceedance of the Aquifer Water Quality Standard for nitrate at a point or points of current or reasonably foreseeable use of the aquifer, the Director shall use the following criteria to determine whether to designate the area as a Nitrogen Management Area:

a. Population of the area;

b. The degree to which the area is unsewered;

c. Gross areal nitrogen loading, calculated as the amount of nitrogen discharged into the subsurface by use of on-site wastewater treatment facilities, divided by the land area under consideration for designation as a Nitrogen Management Area;

d. Population growth rate of area;

e. Existing contamination of groundwater by nitrogen species;

f. Existing and potential impact to groundwater by sources of nitrogen other than on-site wastewater treatment facilities;

g. Characteristics of the vadose zone and aquifer;

h. Location, number, and areal extent of existing and potential sources of nitrogen;

i. Location and characteristics of existing and potential drinking water supplies; and

j. Any other information relevant to determining the severity of actual or potential nitrogen impact on the aquifer.

2. The Director may modify the boundaries or requirements of a Nitrogen Management Area or rescind designation of a Nitrogen Management Area based on:

a. A material change to one or more criterion specified in subsection (A)(1); or

b. The adoption by a local agency of a master plan to substantially sewer the area as soon as possible, but with a completion deadline within 10 years, unless a completion deadline of more than 10 years is approved by the Director.

B. Preliminary designation, modification, or rescission.

1. The Director shall provide a report to the mayors and members of the Board of Supervisors of all towns, cities, and counties and the directors of all sanitary districts affected by the Department's proposed action to designate, modify, or rescind a Nitrogen Management Area as follows:

a. If the Department proposes to designate a Nitrogen Management Area, the Department shall provide a report discussing each criterion specified in subsection (A)(1).

b. If the Department proposes to modify the boundaries or requirements of a Nitrogen Management Area or rescind the designation of a Nitrogen Management Area, the Department shall provide a report discussing applicable criteria in subsections (A)(1) and (2).

2. The town, city, county, or sanitary district receiving the Director's report may provide written comments to the Department within 120 days to dispute the factual information presented in the report and supply any information supporting the comments.

3. The Director shall evaluate the comments and supporting information obtained under subsection (B)(2) and either designate, modify, or rescind the Nitrogen Management Area or withdraw the proposal.

C. Final designation.

1. If the Director designates or modifies the Nitrogen Management Area, the Department shall:

a. Issue or modify the Nitrogen Management Area designation and any special provisions established for the area to control groundwater pollution by sources of nitrogen regulated by Title 49, Chapter 2, Article 3 of the Arizona Revised Statutes but not covered under an individual permit. The Department shall provide notice to the mayors and members of the Board of Supervisors of all towns, cities, and counties and the directors of all sanitary districts affected by the determination;

b. Maintain the designation and a map showing the boundaries of the Nitrogen Management Area at the Arizona Department of Environmental Quality, 1110 West Washington, Phoenix, Arizona 85007 and on the Department's web site at www.azdeq.gov; and

c. Provide, upon request, a copy of the Nitrogen Management Area designation and a map of the area.

2. If the Director withdraws the preliminary Nitrogen Management Area designation or rescinds the Nitrogen Management Area designation, the Director shall issue a determination stating the decision and post it on the Department's web site at www.azdeq.gov.

D. Nitrogen Management Area requirements. Within a Nitrogen Management Area:

1. The Department shall issue a Construction Authorization, under R18-9-A301(D)(1)(c), for an on-site wastewater treatment facility only if the applicant proposes, in the Notice of Intent to Discharge, to employ one or more of the technologies allowed under R18-9-E302 through R18-9-E322 that achieves a discharge level containing not more than 15 mg/l of total nitrogen.

2. An agricultural operation shall use the best control measure necessary to reduce nitrogen discharge when implementing the best management practices developed under 18 A.A.C. 9, Article 4. The Director may require the owner or operator to reassess the performance of the impoundment liner systems constructed under R18-9-403 before November 12, 2005.

3. A person shall comply with any special provision established for the Nitrogen Management Area, as applicable, for the person's facility.

Ariz. Admin. Code § R18-9-A317

New Section made by final rulemaking at 11 A.A.R. 4544, effective November 12, 2005 (05-3).