Mississippi Administrative Code › Title 11 - Mississippi Department of Environmental Quality › Part 6 - Wastewater Pollution Control Regulations › Chapter 2 - Mississippi Commission on Environmental Quality Regulations for Water Quality Criteria For Intrastate, Interstate, And Coastal Waters › Rule 11-6-2.4 - Waterbody-Specific Water Quality Criteria

Current through June 25, 2024
A.
Chlorides, Sulfates, and Total Dissolved Solids (TDS) in the
				Mississippi River
:
The Mississippi River is classified as Fish and Wildlife. All
				  water quality criteria for the Fish and Wildlife classification apply but with
				  the following additions to the criteria stated herein:
Mineral Constituents
: Not to exceed
				  the following concentrations at any time:
From Mississippi-Tennessee border to
				  Vicksburg
Chlorides
60 mg/l
Sulfates
150 mg/l
TDS
425 mg/l
From Vicksburg south to the Mississippi-Louisiana
				  border
Chlorides
75 mg/l
Sulfates
120 mg/l
TDS
400 mg/l
B.
				Nickel in the Mississippi Sound
The Mississippi Sound is classified as Recreation. The
				  waterbody runs east-west along Mississippi Coast. The Mississippi Sound is
				  separated from the Gulf of Mexico on its southern side by the
				  Mississippi-Alabama barrier islands. The following nickel criteria are
				  applicable for this waterbody for the protection of aquatic life:
Acute
167 µg/l
Chronic
18.5 µg/l
C.
				Dissolved Oxygen in the Escatawpa River:
The Escatawpa River is located within Jackson County in
				  southeast Mississippi. The waterbody is located within the Pascagoula River
				  Basin is classified as Fish and Wildlife. Sitespecific criteria for dissolved
				  oxygen apply to a segment of the Escatawpa River from river mile 10 to its
				  mouth at the Pascagoula River. The following dissolved oxygen standard is
				  applicable for this segment:
Dissolved oxygen concentrations shall not be less than a
				  daily average of 3.7 mg/l from May 1 through October 31. Additional information
				  regarding the derivation and implementation of this criterion can be found in
				  MDEQ the report titled,
A SiteSpecific Dissolved Oxygen Criterion for
				  the Escatawpa River: Criteria Derivation and Implementation
.
D. Selenium in Little Bywy Creek,
				Middle Bywy Creek, and Big Bywy Ditch
Little Bywy Creek, Middle Bywy Creek, and Big Bywy Ditch are
				  located within Choctaw and Montgomery Counties in central Mississippi. These
				  water bodies are located within the Big Black River Basin and are all
				  classified as Fish and Wildlife. Site-specific criteria for selenium apply to
				  the following waterbody segments:
Little Bywy Creek: From the headwaters to its mouth at Middle
				  Bywy Creek
Middle Bywy Creek: From its headwaters to its mouth at Big
				  Bywy Ditch
Big Bywy Ditch: From the confluence with Middle Bywy Creek to
				  its mouth at the Big Black River
The following selenium criteria apply for the segments listed
				  above:
Media Type
Fish Tissue
Water Column
Criterion Element
Egg/Ovary
Fish Whole Body or Muscle
Monthly Average Exposure
Magnitude
15.1 mg/kg (dry weight)
Whole body: 8.5 mg/kg (dry weight)
or
Muscle:
11.3 mg/kg (dry weight) (skinless, boneless
								fillet)
1.5 µg/L in lentic aquatic systems
or
3.1 µg/L in lotic aquatic system
Duration
Instantaneous
Instantaneous
30 days
Frequency
Not to be exceeded
Not to be exceeded
Not more than once in three years on
								average
1. Fish tissue
				elements are expressed as steady-state.
2. Egg/Ovary supersedes any whole-body,
				muscle, or water column element when fish egg/ovary concentrations are
				measured.
3. Fish whole-body or
				muscle tissue supersedes water column element when both fish tissue and water
				concentrations are measured.
4.
				Water column values are based on dissolved total selenium in water and are
				derived from fish tissue values via bioaccumulation modeling. Water column
				values are the applicable criterion element in the absence of steady-state
				condition fish tissue data.
5. Fish
				tissue data provide instantaneous point measurements that reflect integrative
				accumulation of selenium over time and space in fish population(s) at a given
				site.