NAC445A.2166. Colorado Region: Virgin River at Lake Mead.  


Latest version.
  • The limits of this table apply to the body of water known as the Virgin River from Mesquite to the river mouth at Lake Mead. This segment of the Virgin River is located in Clark County.

    STANDARDS OF WATER QUALITY

    Virgin River at Lake Mead

    PARAMETER

    REQUIREMENTS

    TO MAINTAIN

    EXISTING HIGHER

    QUALITY

    WATER QUALITY

    STANDARDS FOR

    BENEFICIAL USES

    Beneficial Usea

    Livestock

    Irrigation

    Aquatic

    Contact

    Noncontact

    Municipal

    Industrial

    Wildlife

    Aesthetic

    Enhance

    Marsh

    Beneficial Uses

    X

    X

    X

    X

    X

    X

    Aquatic Life Species of Concern

    Temperature - °C

    ΔTb - °C

    DT

    = 0

    S.V. Nov-Jun

    S.V. Jul-Oct

    DT

    ≤ 21

    ≤ 32

    ≤ 2

    *

    pH - SU

    S.V.

    DpH

    6.5 - 9.0

    ± 0.5

    X

    X

    *

    X

    X

    *

    Dissolved Oxygen - mg/l

    S.V.

    ≥ 5.0

    X

    *

    X

    X

    Total Phosphates

    (as P) - mg/l

    A-Avg.

    ≤ 0.1

    *

    X

    Nitrogen Species

    (as N) - mg/l

    Total Nitrogen

    Nitrate S.V.

    Nitrite S.V.

    ≤ 90

    ≤ 5.0

    X

    *

    X

    X

    A-Avg.

    S.V.

    ≤ 2.9

    ≤ 6.1

    Total Ammonia

    (as N) - mg/l

    c

    *

    Turbidity - NTU

    d

    *

    Color - PCU

    e

    *

    Total Dissolved Solids - mg/l

    f

    X

    *

    Alkalinity

    (as CaCO3) - mg/l

    < 25% change from natural conditions

    *

    X

    E. coli - No./100 ml

    A.G.M.

    ≤ 630

    *

    Fecal Coliform - No./100 ml

    A.G.M.

    S.V.

    ≤ 625

    ≤ 1250

    S.V.

    ≤ 1,000

    X

    *

    X

    X

    * = The most restrictive beneficial use.

    X = Beneficial use.

    a     Refer to NAC 445A.122 and 445A.2142 for beneficial use terminology.

    b     Maximum allowable increase in temperature above water temperature at the boundary of an approved mixing zone, but the increase must not cause a violation of the single value standard.

    c     The ambient water quality criteria for ammonia are specified in NAC 445A.118.

    d     Increase in turbidity must not be more than 10 NTU above natural conditions.

    e     Increase in color must not be more than 10 PCU above natural conditions.

    f     The salinity standard for the Colorado River System is specified in NAC 445A.1233.

     (Added to NAC by Environmental Comm’n by R160-06, eff. 8-26-2008; A by R131-12, 12-20-2012)