Ariz. Admin. Code § R18-11-217 - Best Management Practices for non-WOTUS Protected Surface Waters

A. The BMPs described in this rule are intended to ensure that activities within the ordinary high-water mark of perennial or intermittent non-WOTUS protected surface waters, or within the bed and bank of other waters that materially impact (i.e., are within 1/4 mile upstream of) non-WOTUS protected surface waters, do not violate applicable surface water quality standards in the non-WOTUS protected surface waters. For purposes of this section, the activities described in the prior sentence will be referred to as "regulated activities." Depending on the regulated activities conducted, not all of the BMPs described below may be applicable to a particular project. The owner or operator is responsible to consider the BMPs outlined below and to implement those necessary to ensure that the regulated activities will not violate applicable surface water quality standards in the non-WOTUS protected surface water.

B. The BMPs described below are not applicable to any activities that are addressed under an individual or general AZPDES permit that are otherwise regulated under A.R.S. Title 49.

C. Erosion and sedimentation control BMPs:

1. When flow is present in any non-WOTUS protected surface waters within a project area, flow shall not be altered except to prevent erosion or pollution of any non-WOTUS protected surface waters.

2. Any disturbance within the ordinary high-water mark of non-WOTUS protected surface waters or within the bed and banks of other waters, that is not intended to be permanently altered, shall be stabilized as soon as practicable to prevent erosion and sedimentation.

3. When flow in any non-WOTUS protected surface water is sufficient to erode, carry, or deposit material, regulated activities shall cease until:

a. The flow decreases below the point where sediment movement ceases; or

b. Control measures have been undertaken, i.e., equipment and material easily transported by flow are protected within non-erodible barriers or moved outside the flow area.

4. Silt laden or turbid water resulting from regulated activities should be managed in a manner to reduce sediment load prior to discharging.

5. No washing or dewatering of fill material should occur within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface waters. Other than the replacement of native fill or material used to support vegetation rooting or growth, fill placed within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface water must resist washout whether such resistance is derived via particle size limits, presence of a binder, vegetation, or other armoring.

D. Pollutant management BMPs:

1. If regulated activities are likely to violate applicable surface water quality standards in a perennial or intermittent non-WOTUS protected surface water, operations shall cease until the problem is resolved or until control measures have been implemented.

2. Construction material and/or fill (other than native fill or that necessary to support revegetation) placed within surface waters as a result of regulated activities shall not include pollutants in concentrations that will violate applicable surface water quality standards in a perennial or intermittent non-WOTUS protected surface water.

E. Construction phase BMPs:

1. Equipment staging and storage areas or fuel, oil, and other petroleum products storage and solid waste containment should not be located within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface water.

2. Any equipment maintenance, washing, or fueling shall not be done within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface waters with the following exception: Equipment too large or unwieldy to be readily moved, such as large cranes, may be fueled and serviced in non-WOTUS protected surface waters (but outside of standing or flowing water) provided material specifically manufactured and sold as spill containment is in place during fueling/servicing.

3. All equipment shall be inspected for leaks, all leaks shall be repaired, and all repaired equipment shall be cleaned to remove any fuel or other fluid residue prior to use within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface waters.

4. Washout of concrete handling equipment shall not take place within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface waters.

F. Post-construction BMPs:

1. Upon completion of regulated activities, areas within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface waters shall be promptly cleared of all forms, piling, construction residues, equipment, debris, or other obstructions.

2. If fully, partially, or occasionally submerged structures are constructed of cast-in-place concrete instead of pre-cast concrete, steps will be taken using sheet piling or temporary dams to prevent contact between water (instream and runoff) and the concrete until it cures and until any curing agents have evaporated or are no longer a pollutant threat.

3. Any permanent water crossings within the ordinary high-water mark of any perennial or intermittent in a non-WOTUS protected surface water (other than fords) shall not be equipped with gutters, drains, scuppers, or other conveyances that allow untreated runoff (due to events equal to or lesser in magnitude than the design event for the crossing structure) to directly enter a non-WOTUS protected surface water if such runoff can be directed to a local stormwater drainage, containment, and/or treatment system.

4. Debris shall be cleared as needed from culverts, ditches, dips, and other drainage structures within the ordinary high-water mark of any perennial or intermittent non-WOTUS protected surface water to prevent clogging or conditions that may lead to a washout.

5. Temporary structures constructed or imported materials shall be removed no later than upon completion of the regulated activities.

6. Temporary structures constructed of native materials, if they provide an obstacle to flow or can contribute to or cause erosion, or cause changes in sediment load, shall be removed no later than upon completion of the regulated activities.

G. Design consideration BMPs:

1. All temporary structures constructed of imported materials and all permanent structures, including but not limited to, access roadways, culvert crossings, staging areas, material stockpiles, berms, dikes, and pads, shall be constructed so as to accommodate overtopping and resist washout by streamflow.

2. Any temporary crossing, other than fords on native material, shall be constructed in such a manner so as to provide armoring of the stream channel. Materials used to provide this armoring shall not include anything easily transportable by flow. Examples of acceptable materials include steel plates, untreated wooden planks, pre-cast concrete planks or blocks. Examples of unacceptable materials include clay, silt, sand, and gravel finer than cobble (roughly fist-sized). The armoring shall, via mass, anchoring systems, or a combination of the two, resist washout.

H. Notification. The owner or operator of any regulated activities shall, five days prior to initiation of the regulated activities, submit a notice to ADEQ on a form that includes basic information including the GPS location, the waterbody ID of the nearest non-WOTUS protected surface water, general description of planned activities, types of BMPs to be employed during the project, and phone number and email for a contact person. Work may proceed after five calendar days have passed since the owner/operator provided notification to ADEQ unless ADEQ responds in writing to the contact person for the owner/operator.

I. Exclusions: The BMPS and notification requirements in this section shall not apply to:

1. Activities that are already regulated under A.R.S. Title 49.

2. Discharges to a non-WOTUS protected surface water incidental to a recharge project.

3. Established or ongoing farming, ranching and silviculture activities such as plowing, seeding, cultivating, minor drainage or harvesting for the production of food, fiber or forest products or upland soil and water conservation practices.

4. Maintenance but not construction of drainage ditches.

5. Construction and maintenance of irrigation ditches.

6. Maintenance of structures as dams, dikes, and levees.

Notes

Ariz. Admin. Code § R18-11-217

New Section made by final rulemaking at 29 A.A.R. 302, effective 2/20/2023.