SEC Regulatory Meeting December 5, 2017

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Time
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Location
9:00 A.M.
Tuesday, December 5, 2017
Nevada Legislative Building, Room 4100,
401 South Carson Street
Carson City, NV
 
Video-conference:
Grant Sawyer Building, Room 4412E,
555 East Washington Avenue
Las Vegas, NV

Minutes, Agenda, & Audio


NDEP Regulatory Petitions

Permanent Regulation R102-16

The proposed amendment pertains to NAC Chapter 445A. The NDEP is proposing to amend NAC 445A.070 – 445A.2234, Standards for Water Quality, to align with the most current recommended numeric criteria published by the federal EPA for Escherichia coli (E. coli) bacteria to protect the water contact recreation beneficial use. The proposed revisions include: (1) change the existing reference period from annual geometric mean (AGM) to geometric mean (GM) for all waters that have an existing AGM to protect the water contact recreation beneficial use; (2) change the unit of measurement from most probable number (MPN) per 100 mL to colony-forming-units (CFU) per 100 mL; (3) remove existing single value (SV) criteria of 235 MPN, 298 MPN and 576 MPN and replace with a SV of 410 CFU; (4) add a footnote that explains frequency and duration limits of the GM and SV criteria; and (5) add a definition of colony-forming-units.

EPA’s water quality standards regulations at 40 CFR 131.11(a)(1) require states to adopt protective criteria that are based on sound scientific rationale. Nevada’s existing E. coli bacteria standards for the protection of the water contact recreation beneficial use are based on EPA criteria published in 1986. EPA published updated E. coli bacteria criteria in 2012. The 2012 criteria reflect significant research and new scientific developments that have occurred since 1986.

The new criteria comprise a more defined duration and frequency. The current AGM is changed to a GM that must be met in any 30-day interval. The existing E. coli standards include single value criteria for different levels of use (Beach—SV 235; Moderate—SV 298; Light—SV 410; and Infrequent—SV 576). The new criteria contain one single value, 410, that must not be exceeded more than ten percent of the time in any 30-day interval. This criterion has been determined to be protective of all levels of use. The method used to estimate colony-forming-units has been determined to be less variable than the method used to estimate the most probable number and therefore CFU estimates better reflect the true bacteria levels in a given sample.

To maintain a more restrictive standard to protect the Lake Tahoe designation of a Water of Extraordinary Aesthetic or Ecological Value, the existing S.V. 126 standard is being retained and a GM is not being proposed for Lake Tahoe and its tributaries. The units are being changed from MPN to CFU and a footnote indicating that the S.V. must not be exceeded more than ten percent of the time in any 30-day interval is being added.

Adoption of EPA’s 2012 criteria ensures the most appropriate protection for recreational users of Nevada’s surface waters.
This regulation will not have an immediate or long-term adverse economic impact on regulated business/industry or the public. There will be no additional costs to the State for enforcement of the proposed regulation and the regulation does not overlap, duplicate or conflict with any regulations of other government agencies. The proposed regulation does not include provisions which are more stringent than a federal regulation. The proposed regulation does not address fees and it is essential to the functions and operations of NDEP.

Supporting PDF Documents


Permanent Regulation R109-16

The proposed amendment pertains to NAC Chapter 445A. The NDEP is proposing to amend NAC 445A.070 – 445A.2234, Standards for Water Quality, by making numerous numeric criteria and formatting changes that will provide clarity and consistency throughout the water quality standards (WQS) tables. The proposed revisions include: (1) remove references to “natural conditions” or “no adverse effects” and establish numeric criteria for alkalinity, color and turbidity based on the most current federal EPA criteria; (2) remove references to the 95th percentile for the total dissolved solids beneficial use numeric criteria; (3) remove Xs in the Beneficial Use columns that refer to secondary uses; (4) reformat how the nitrogen species are presented in the WQS tables; (5) add a footnote that specifies the NAC criteria for Toxic Materials; (6) move the ammonia standards tables so they occur after standards applicability discussions and beneficial uses; and (7) make other minor formatting changes for clarity and consistency of parameter names and units throughout all the WQS tables.

EPA’s water quality standards regulations at 40 CFR 131.11(a) (1) require states to adopt protective criteria that are based on sound scientific rationale. Many waterbodies contained in the NAC have criteria that reference “natural conditions” or “no adverse effects” for alkalinity, color and turbidity; however, it is difficult to determine natural baseline conditions making it problematic to assess if the standards are being met and to establish discharge permit limits. Numeric criteria based on the most recent EPA recommended criteria are proposed for alkalinity (single value (S.V.) = 20 mg/L), color (S.V. = 75 PCU), and turbidity (= 10 NTU).

The existing total dissolved solids (TDS) numeric criteria for many streams is “S.V. =500 mg/l or the 95th percentile (whichever is less)”. All references to the 95th percentile value will be removed as this is inappropriate as a beneficial use standard. Higher water quality is protected through anti-degradation requirements.

The numeric criteria shown in the Water Quality to Protect Beneficial Uses column in the WQS tables are designed to protect the most restrictive use which is indicated in the Beneficial Uses columns by an asterisk. Inconsistencies throughout the WQS tables associated with the most restrictive use protected by a given parameter are being corrected. The current practice of indicating secondary uses with an X is not clear and is inconsistent throughout the WQS tables. Since it is assumed that any secondary uses associated with a particular parameter are protected under the most restrictive use, the Xs indicating secondary uses are not necessary. Removing the Xs simplifies the Beneficial Uses columns and makes it easier to see the most restrictive use.

The nitrogen species are currently placed in one row in the WQS tables. For clarification, each species (total nitrogen, nitrate and nitrite) will be placed in separate rows. No changes to the numeric criteria are being proposed at this time.

Water quality criteria for toxic materials applicable to all named waters are contained in NAC 445A.1236. For clarification a footnote specifying the NAC reference is being added to each WQS table.

The NAC reference to ammonia is being moved to place the standards for ammonia after the discussions of applicability, standards applicable to all surface waters and discussions of beneficial uses.

Other revisions for clarification, correctness and consistency include: (1) changing mg/l to mg/L; (2) changing Total Phosphates to Total Phosphorus; (3) changing Suspended Solids to Total Suspended Solids and (4) updating the reference to the Colorado River Salinity Standards to 2014.
This regulation will not have an immediate or long-term adverse economic impact on regulated business/industry or the public. There will be no additional costs to the State for enforcement of the proposed regulation and the regulation does not overlap, duplicate or conflict with any regulations of other government agencies. The proposed regulation does not include provisions which are more stringent than a federal regulation. The proposed regulation does not address fees and it is essential to the functions and operations of NDEP.

Supporting PDF Documents