Sediment and Nutrient Criteria in EPA-Permitted States

Table 1 Established Sediment and Nutrient Criteria in EPA-Permitted States, Territories, and Tribes

Region State/Tribe Sediment Water Quality Standard Nutrients Water Quality Standard

1 New Hampshire

http://des.nh.gov/

organization/com

missioner/legal/ru

les/documents/en

v-wq1700.pdf

TURBIDITY

A discharge may not cause or contribute to a turbidity increase 

of 10 NTU or more above the turbidity of the receiving water 

upstream of the discharge or otherwise outside of the visible 

discharge. 

Class A waters – No discharge allowed1.

Class B waters – No turbidity increase over 10 NTUs above 

background conditions.

NITROGEN

Class A waters – No discharge 

allowed1.

Class B waters – Narrative 

standard.

PHOSPHORUS

Class A waters – No discharge 

allowed1.

Class B waters – Narrative 

standard.

Lakes and Ponds – No 

discharge allowed1.

Massachusetts 

Surface Water 

Quality 

Standards, the 

and 

http://www.mass.

gov/dep/service/r

egulations/314cm

r04.pdf

NARRATIVE STANDARD ONLY NARRATIVE STANDARD ONLY

Mashpee 

Wampanoag 

Indian Tribal 

Council, Inc. 

TURBIDITY

Narrative Standard Only NARRATIVE STANDARD ONLY

Wampanoag 

Tribe of Gay 

Head

TURBIDITY

Narrative Standard Only NARRATIVE STANDARD ONLY

2 Puerto Rico 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/pr/pr_2_wqs.p

df

TURBIDITY

Class SB Waters (coastal and estuarine waters) and SC Waters 

(coastal waters) – Turbidity must not exceed 10 NTU, except 

by natural causes.

Class SD Waters (surface waters for public water supply) –

Turbidity must not exceed 50 NTU, except by natural causes.

Class SG1 Waters (ground waters for drinking water/ag use) –

Narrative standard.

PHOSPHORUS

Class SD Waters – Total phosphorus must not exceed 1 ppm in 

surface water bodies upstream from reservoirs, in segments of surface 

water bodies with drinking water intakes, or estuarine waters except 

when it is demonstrated to the satisfaction of the Board that a higher 

value of total phosphorus in combination with prevailing nitrogen 

derived nutrients will not contribute to eutrophic conditions in the 

water body. 

 

1

Sampling must not detect any of the pollutant in the discharge. 
St. Regis 

Mohawk Tribe

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/srmt_2_

%20wqs.pdf

TOTAL DISSOLVED SOLIDS

Must not increase by more than 1/3 of naturally-occurring 

levels, and must not exceed 500 mg/L.

NARRATIVE STANDARD ONLY

3 District of 

Columbia

TURBIDITY

Classes A, B, & C Waters – No turbidity increase over 20 

NTUs above background conditions.

NONE

4 Seminole Tribe 

of Florida

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/semi_tri

be_fl_4_wqs.pdf

TURBIDITY

Class I, II-B, II-C, and III Waters – No turbidity increase over

29 NTUs above background conditions.

Class II-A Waters - Narrative standard only. NARRATIVE STANDARD ONLY

Miccosukee 

Tribe 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/fl_4_mic

cosukee.pdf

TURBIDITY

Class I and III-A Waters – No turbidity increase over 29 NTUs

above background conditions.

Class III-B Waters – No turbidity increase over 29 NTUs above 

background conditions.

NARRATIVE STANDARD ONLY

5 Fon du Lac 

Band of Lake 

Superior 

Chippewa

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/chippew

a.pdf

TURBIDITY

Settleable and suspended solids must not reduce the depth of 

the compensation point for photosynthetic activity by more than 

10% from the seasonally established norm for aquatic life.

NARRATIVE STANDARD ONLY

6 New Mexico 

http://www.nmcp

r.state.nm.us/nma

c/parts/title20/20.

006.0004.pdf

TURBIDITY

Turbidity shall not exceed 10 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 20 percent when the background turbidity is more 

than 50 NTU.

NARRATIVE STANDARD ONLY
Ohkay 

Owingeh 

(Pueblo of San 

Juan) 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/ohk

ay.pdf

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 10 percent when the background turbidity is more 

than 50 NTU.

Primary Contact Ceremonial Use - Turbidity must not exceed

25 NTU's.

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/o

hkay.pdf .

NITROGEN

Primary Contact Ceremonial Use – Nitrate must not exceed 10.0 mg/l.

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/ohkay.pd

f .

Pueblo of 

Acoma Water 

Quality 

Standards 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/aco

ma.pdf

TOTAL DISSOLVED 

SOLIDS

Warm Water Habitat, Cold 

Water Habitat, Ephemeral, 

Domestic Water Source and 

Groundwater Recharge, and 

Primary Contact Recreational 

– Total dissolved solids must 

not exceed 1000 mg/L

TURBIDITY

Turbidity shall not exceed 5

NTU over background

turbidity when the background 

turbidity is 50 NTU or less, or 

increase more than 10 percent

when the background turbidity 

is more than 50 NTU.

Domestic Water Source and 

Groundwater Recharge, and 

Primary Contact Recreational 

– Turbidity Must Not Exceed 

25 NTU Warmwater Habitat, 

Coldwater Habitat, 

Ephemeral, Fish 

Consumption, Agricultural 

Irrigation, Agricultural 

Livestock Watering, and 

Partial Body Contact – ≤5 

NTU variation for waters with 

≤ 50 NTU background and a 

10% increase from 

background for waters >50 

NTU.

NITROGEN

Domestic Water Source and 

Groundwater Recharge, Primary 

Contact Recreational, and Partial 

Body Contact: Nitrogen –Nitrate 

must not exceed 10.0 mg/L

PHOSPHORUS

Streams - Total phosphorus must 

not exceed 100 ug/L

Lakes and Reservoirs – Total 

phosphorus must not exceed 50 

ug/L

Pueblo of Isleta 

http://www.epa.

gov/waterscienc

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

NITROGEN

Primary Contact Ceremonial – Total inorganic nitrogen must not 

exceed 10 mg/L.
e/standards/wqsl

ibrary/tribes/isle

ta_6_wqs.pdf

more than 10 percent when the background turbidity is more 

than 50 NTU.

Pueblo of 

Nambe 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/na

mbe_ween_6_w

qs.pdf

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 10 percent when the background turbidity is more 

than 50 NTU.

High Quality Coldwater Fishery Use - Turbidity must not 

exceed 10 NTU (25 NTU in certain reaches where natural 

background prevents attainment of lower turbidity). 

Primary Contact - Turbidity shall not exceed 25 NTU.

NITROGEN

High Quality Coldwater Fishery 

Use - Total inorganic Nitrogen 

(as N) shall not exceed 1.0 mg/L

Recharge of Domestic Water 

Supply – Nitrates must not 

exceed 10.0 mg/L

PHOSPHORUS

High Quality Coldwater Fishery 

Use - Total phosphorus must not 

exceed 0.1 mg/L

Pueblo of 

Picuris 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/pic

uris_6_wqs.pdf

TOTAL DISSOLVED 

SOLIDS

Total dissolved solids of 

mineral constituents must not 

exceed 500 mg/L.

TURBIDITY

Turbidity shall not exceed 5

NTU over background

turbidity when the background 

turbidity is 30 NTU or less, or 

increase more than 10 percent

when the background turbidity 

is more than 30 NTU.

High Quality Coldwater 

Fishery, Primary Contact Use

- Turbidity must not exceed 

10 NTU (25 NTU in certain 

reaches where natural 

background prevents 

attainment of lower turbidity). 

Primary Contact - Turbidity 

shall not exceed 10 NTU.

NITROGEN

High Quality Coldwater Fishery 

Use - Total inorganic Nitrogen 

(as N) shall not exceed 1.0 mg/L

Recharge of Domestic Water 

Supply – Nitrates must not 

exceed 10.0 mg/L

PHOSPHORUS

High Quality Coldwater Fishery 

Use - Total phosphorus must not 

exceed 0.1 mg/L

Pueblo of 

Pojoaque 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/poj

oaque_6_wqs.p

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 10 percent when the background turbidity is more 

than 50 NTU.

Primary contact – Turbidity must not exceed 25 NTU.

NITROGEN:

Segments Designated for Groundwater Recharge - Total Nitrates, as N, 

must not exceed 10.0 mg/L.
df

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/p

ojoaque_6_wqs.pdf.

Pueblo of 

Sandia 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/san

dia_6_wqs.pdf

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 10 percent when the background turbidity is more 

than 50 NTU.

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/sa

ndia_6_wqs.pdf.

PHOSPHORUS:

As a guideline, total phosphorus shall not exceed 100 ug/liter in 

stream or 50 ug/liter in lakes and reservoirs.

Pueblo of 

Santa Clara 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/san

ta_clara_6_wqs.

pdf

TOTAL DISSOLVED 

SOLIDS

Primary Contact - Total 

dissolved solids of mineral 

constituents must not exceed 

500 mg/L.

TURBIDITY

Turbidity shall not exceed 5

NTU over background

turbidity when the background 

turbidity is 50 NTU or less, or 

increase more than 10 percent

when the background turbidity 

is more than 50 NTU.

Fish Culture and High-Quality 

Cold Water Fisheries -

Turbidity must be less than 10 

NTU, except in certain 

reaches where natural 

background conditions 

prevent attainment of lower 

turbidity. In that instance, 

turbidity shall be less than 25 

NTU. 

Primary contact - Turbidity 

must not exceed 25 NTUs.

PHOSPHORUS

Fish Culture and High-Quality Cold Water Fisheries -

Total phosphorus must not exceed 0.1 mg/L.

Pueblo of Taos 

http://www.epa.

TURBIDITY

Drinking Water – Turbidity must not exceed 5 NTU.

NITROGEN

Drinking Water Standards - Nitrite must not exceed 1,000 ug/L.
gov/waterscienc

e/standards/wqsl

ibrary/tribes/tao

s-200606.pdf

High Quality Cold Water Fishery – Turbidity must not exceed 

10 NTU.

Nitrate + Nitrite must not exceed 10,000 ug/L.

Domestic Water Supply - Nitrate must not exceed 10,000 ug/L.

Pueblo of 

Tesuque 

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/tes

uque_6_wqs.pdf

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 10 percent when the background turbidity is more 

than 50 NTU.

High Quality Coldwater Fishery Use - Turbidity must not 

exceed to 10 NTU (25 NTU in certain reaches where natural 

background prevents attainment of lower turbidity). 

Primary Contact - Turbidity must not exceed 25 NTUs.

NITROGEN

High Quality Coldwater Fishery 

Use - Total inorganic nitrogen 

must not exceed 1.0 mg/L.

Groundwater Recharge - Nitrates 

must not exceed 10.0 mg/L.

PHOSPHORUS

High Quality Coldwater Fishery 

Use - Total phosphorus must not 

exceed 0.1 mg/L.

8 Confederated 

Salish and 

Kootenai 

Tribes of the 

Flathead 

Reservation

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/sali

sh_kootenai_8_

wqs.pdf

TURBIDITY

A-Closed and A-1 Waters - No discharge allowed1.

B-1 and C-1 Waters - No turbidity increase over 5 NTU above 

background conditions.

B-2, B-3, C-2, and C-3 Waters – No turbidity increase over 10 

NTU above background conditions. NARRATIVE STANDARD ONLY

Assiniboine 

and Sioux 

Tribes of the 

Fort Peck 

Indian 

Reservation

http://www.epa.

gov/waterscienc

e/standards/wqsl

ibrary/tribes/fort

_peck_8_wqs.p

df

See Fort Peck Tribe Numeric Water Quality Standards: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/fo

rt_peck_8_wqs.pdf

See Fort Peck Tribe Numeric Water Quality Standards: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/fort_pec

k_8_wqs.pdf

9 The Island of TURBIDITY NITROGEN PHOSPHORUS
American 

Samoa 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/territories/ame

rican_samoa_9_

wqs.pdf

Fresh Surface Waters - Turbidity average not to exceed 5 NTU.

Embayments - Turbidity average not to exceed 0.35 NTU.

Pago Pago Harbor - Turbidity average not to exceed 0.75 NTU.

Embayments – Fagatele Bay and Pala Lagoon - Turbidity 

average not to exceed 0.25 NTU (Fagatele Bay) and 0.75 NTU

(Pala Lagoon).

Open Coastal Waters - Turbidity average not to exceed 0.25 

NTU.

Ocean Waters - Turbidity average not to exceed 0.20 NTU. 

Fresh Surface Waters - Total 

Nitrogen average must not exceed 

300 mg/l as N.

Embayments - Total Nitrogen 

average must not exceed 150.0 

mg/l as N.

Pago Pago Harbor - Total 

Nitrogen average must not exceed

200 mg/l as N.

Embayments – Fagatele Bay and 

Pala Lagoon - Total Nitrogen 

average must not exceed 135 

mg/l as N.

Open Coastal Waters - Total 

Nitrogen average must not exceed

130.0 mg/l as N.

Ocean Waters - Total Nitrogen 

average must not exceed 115.0 

mg/l as N.

Fresh Surface Waters -Total 

Phosphorus average must not

exceed 150 mg/l as P.

Embayments - Total Phosphorus 

average must not exceed 20.0 

mg/l as P.

Pago Pago Harbor - Total 

Phosphorus average must not

exceed 30.0 mg/l as P.

Embayments – Fagatele Bay and 

Pala Lagoon - Total Phosphorus 

average must not exceed 15 mg/l

as P.

Open Coastal Waters -Total 

Phosphorus average must not

exceed 15.0 mg/l as P.

Ocean Waters - Total Phosphorus 

average must not exceed 11.0 

mg/l as P.

The Island of 

Guam 

http://node.guame

pa.net/programs/

water/WQS.pdf

TOTAL NONFILTERABLE 

SUSPENDED SOLIDS

M-1 and S-1 Waters – Must 

not exceed 5 mg/L, except 

when due to natural 

conditions.

M-2 and S-2 Waters –

Concentrations must not be 

increased by more then 10%

from background, and the 

total concentration must not 

exceed 20 mg/L, except when 

due to natural conditions.

M-3 and S-3 Waters –

Concentrations must not be 

increased by more than 25%

from background ,and the 

TURBIDITY

M-1 and S-1 Waters – No 

turbidity increase over 0.5 

NTU above background, 

except when due to natural 

conditions.

M-2, M-3, S-2, and S-3 

Waters – No turbidity increase 

over 1.0 NTU above 

background, except when due 

to natural conditions.

NITROGEN

Groundwater Quality – Nitrate 10 

mg/L; Nitrite 1 mg/L

M-1 and S-1 Waters - Nitratenitrogen shall not exceed 0.10 

mg/l.

M-2 and S-2 Waters - Nitratenitrogen shall not exceed 0.20 

mg/l.

M-3 and S-3 Waters - Nitratenitrogen shall not exceed 0.50 

mg/l.

PHOSPHORUS

M-1 and S-1 Waters -

Orthophosphate must not exceed 

0.024 mg/l.

M-2 and S-2 Waters -

Orthophosphate must not exceed 

0.05 mg/l.

M-3 and S-3 Waters -

Orthophosphate must not exceed 

0.10 mg/l.
total concentration must not 

exceed 40 mg/L, except when 

due to natural conditions.

Johnston Atoll NO WATER QUALITY STD NO WATER QUALITY STD

Midway Island 

and Wake NO WATER QUALITY STD NO WATER QUALITY STD

Commonwealth 

of the Northern 

Mariana Islands

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/territories/nort

hern_mariana_9_

wqs.pdf

TOTAL FILTERABLE 

SUSPENDED SOLIDS

AA, 1 Waters –

Concentrations must not be 

increased above background 

conditions at any time, and 

should not exceed 5 mg/L

except due to natural 

conditions.

A, 2 Waters – Concentrations 

must not be increased above 

background conditions at any 

time, and should not exceed 

40 mg/L except due to natural 

conditions.

TURBIDITY

AA, 1 Waters – No turbidity

increase over 0.5 NTU above

background conditions.

A, 2 Waters – No turbidity 

increase over 1.0 NTU above 

background conditions.

PHOSPHORUS

AA Waters - Orthophosphate concentration must not exceed 0.025

mg/l. Total Phosphorus must not exceed 0.024 mg/l.

A Waters - Orthophosphate concentration must not exceed 0.05 mg/l.

Total Phosphorus must not exceed 0.05 mg/l.

1, 2 Waters - Orthophosphate must not exceed 0.10 mg/l. Total 

Phosphorus must not exceed 0.10 mg/l.

NITROGEN

AA Waters- Nitrate-Nitrogen concentration must not exceed 0.20 

mg/l. Total Nitrogen concentration must not exceed 0.4 mg/l.

A Waters - Nitrate-Nitrogen must not exceed 0.50 mg/l.

A, 1 Waters - Total Nitrogen must not exceed 0.75 mg/L.

2 Waters -Total Nitrogen must not exceed 1.50 mg/l.

Navajo 

Reservation 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/navajo.p

df

SUSPENDED SOLIDS

The following water quality 

standards for suspended solids

concentration, are expressed 

as a median value determined 

from a minimum of four 

samples Collected at least 7 

days apart. A suspended solids 

sample collected during or 

within 48 hours of a local 

precipitation event shall not be 

used to determine the median 

value.

A&WHbt (warm water) – 80 

mg/L

A&WHbt (cold water) – 25 

mg/L

TURBIDITY

Turbidity shall not exceed 10 

NTU over background

turbidity when the background 

turbidity is 50 NTU or less, or 

increase more than 20 percent

when the background turbidity 

is more than 50 NTU.

NITROGEN

PrHC Deep, Shallow, and 

Sedimentary Lake – Total 

nitrogen numeric target 1.2 – 1.4 

mg/L.

PrHC Igneous Lake – Total 

nitrogen numeric target 1.5 – 1.7 

mg/L.

A&WHbt (cold water) – Total 

nitrogen numeric target 1.0 – 1.4 

mg/L.

A&WHbt (warm water) – Total 

nitrogen numeric target 1.6 – 1.8 

mg/L.

Dom – Total nitrogen numeric 

target 1.2 – 1.5 mg/L.

Domestic Water Supply – Nitrate 

must not exceed 10,000 ug/L; 

Nitrite must not exceed 1000 

PHOSPHORUS

PrHC Deep and Shallow Lake –

Total phosphorus numeric target 

70 – 90 ug/L.

PrHC Igneous and Sedimentary 

Lake – Total phosphorus numeric 

target 100 – 125 ug/L.

A&WHbt (cold water) – 50 – 90 

ug/L.

A&WHbt (warm water) – 115 –

140 ug/L.

Dom – 70 – 100 ug/L.
ug/L.

Primary and Secondary Human 

Contact – Nitrate must not exceed 

1493330 ug/L; Nitrite must not 

exceed 93330 ug/L.

Big Pine Paiute 

Tribe of the 

Owens Valley

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/bigpine200601.pdf

SUSPENDED MATERIALS

Natural High Quality Waters –

Concentration must not be 

altered to the extent that such 

alterations are discernible at 

the 10% significance level.

TURBIDITY

Must not increase more than 

10% above natural levels.

NITROGEN

Nitrate (as NO3) must not exceed 10 mg/L.

Nitrite (as nitrogen) must not exceed 1 mg/L.

Nitrite (as nitrogen) must not exceed 0.05 mg/L.

Bishop Paiute 

Tribe

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/bishop.p

df

TURBIDITY

Must not increase more than 10% above natural levels.

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/bishop.p

df

Hoopa Valley 

Tribe

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/hoopa_v

alley.pdf

NOT YET ESTABLISHED

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/hoopa_v

alley.pdf

Hopi Tribe

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/hopi.pdf

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 10 percent when the background turbidity is more 

than 50 NTU.

NITROGEN

Narrative Standard Only

PHOSPHORUS

As a guideline, total phosphorus 

must not exceed 100 ug/L 

instream or 50 ug/L in lakes and 

reservoirs, except in certain 

circumstances.

Pyramid Lake 

Paiute Tribe

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/ca9_pyr

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/ca

9_pyramid.pdf

For uses and standards for designated waterbodies, see: 

http://www.epa.gov/waterscience/standards/wqslibrary/tribes/ca9_pyra

mid.pdf
amid.pdf

White Mountain 

Apache

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/white_m

ountain_9_wqs.p

df

TURBIDITY

Turbidity shall not exceed 5 NTU over background turbidity 

when the background turbidity is 50 NTU or less, or increase 

more than 10 percent when the background turbidity is more 

than 50 NTU.

High-quality coldwater habitat, including cold water fish 

hatchery – Turbidity must be less than 10 NTU, except when 

due to natural conditions. 

Untreated drinking water – Turbidity must not exceed 10 NTU.

Primary contact – Turbidity must not exceed 25 NTU.

Secondary contact recreational – Turbidity must be less than 50 

NTU in river systems and 25 NTU in lakes.

NITROGEN

Domestic/industrial water supply 

– Total nitrate must not exceed 

10.0 mg/L.

PHOSPHORUS

Coldwater habitat, including 

coldwater fish rearing, and high 

quality coldwater habitat, 

including cold water fish hatchery 

– Total phosphorus must be less 

than 0.1 mg/L.

10 Idaho 

http://adm.idaho.

gov/adminrules/r

ules/idapa58/010

2.pdf

TURBIDITY

Turbidity, below any applicable mixing zone set by the 

Department, shall not exceed background turbidity by more 

than 50 NTU instantaneously or more than 25 NTU for more 

than 10 consecutive days.

Surface Water Quality Criteria for Water Supply Use 

Designations – Turbidity as measured at the public water intake 

shall not be: 1) Increased by more than 5 NTU above natural 

background, measured at a location upstream from or not 

influenced by any human induced nonpoint source activity, 

when background turbidity is 50 NTU or less; 2) Increased by 

more than 10% above natural background, measured at a 

location upstream form or not influenced by any human induced 

nonpoint source activity, not to exceed 25 NTU when 

background turbidity is greater than 50 NTU.

Point Source Wastewater Treatment Requirements – The 

wastewater must not increase the turbidity of the receiving 

water outside the mixing zone by: a) More than 5 NTU over 

background turbidity, when background turbidity is 50 NTU or 

less; or b) More than 10% increase in turbidity when 

background turbidity is more than 50 NTU, not to exceed a 

maximum increase of 25 NTU. 

NARRATIVE STANDARD ONLY

Confederated 

Tribes of the 

Chehalis 

TURBIDITY

Class AA & A Waters - Turbidity shall not exceed 5 NTU over 

background turbidity when the background turbidity is 50 NTU

NONE
Reservation 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/chehalis

_10_wqs.pdf

or less, or have more than a 10 percent increase in turbidity 

when the background turbidity is more than 50 NTU.

Class B Waters- Turbidity shall not exceed 10 NTU over 

background turbidity when the background turbidity is 50 NTU

or less, or have more than a 20 percent increase in turbidity 

when the background turbidity is more than 50 NTU.

Confederated 

Tribes of the 

Colville 

Reservation 

http://ecfr.gpoacc

ess.gov/cgi/t/text/

text-

idx?c=ecfr&rgn=

div5&view=text

&node=40:21.0.1

.1.18&idno=40#4

0:21.0.1.1.18.4.1

6.5

TURBIDITY

Class I & II Waters - Turbidity shall not exceed 5 NTU over 

background turbidity when the background turbidity is 50 NTU

or less, or have more than a 10 percent increase in turbidity 

when the background turbidity is more than 50 NTU.

Class III & IV Waters- Turbidity shall not exceed 10 NTU

over background turbidity when the background turbidity is 50 

NTU or less, or have more than a 20 percent increase in 

turbidity when the background turbidity is more than 50 NTU. Lakes & Special Resource Waters - Turbidity shall not exceed 5 

NTU over natural conditions.

NONE

Confederated 

Tribes of the 

Umatilla 

Reservation of 

Oregon 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/umatilla.

pdf

TURBIDITY

Must not increase by more than 10 percent over natural 

conditions as measured relative to a control point immediately 

upstream of any or all turbidity causing activities will not be 

allowed. 

NONE

Confederated 

Tribes of the 

Warm Springs 

Reservation of 

Oregon 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/warmspr

TURBIDITY

Must not increase by more than 10 percent over natural 

conditions as measured relative to a control point immediately 

upstream of any or all turbidity causing activities will not be 

allowed. NONE
ings.pdf

Kalispel Indian 

Reservation 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/kalispel.

pdf

TURBIDITY

Brown Trout Spawning Waters - Turbidity shall not exceed 5 

NTU over background turbidity when the background turbidity 

is 50 NTU or less, or have more than a 10 percent increase in 

turbidity when the background turbidity is more than 50 NTU.

These criteria shall apply between October 1 and March 1 

although site-specific designations may apply at other times:... 

Adult Salmonid Migration Waters - Turbidity shall not exceed 

5 NTU over background turbidity when the background 

turbidity is 50 NTU or less, or have more than a 20 percent

increase in turbidity when the background turbidity is more than 

50 NTU.

NONE

Lummi Indian 

Reservation 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/lummi.p

df

TURBIDITY

Class AA & A Waters - Turbidity shall not exceed 5 NTU over 

background turbidity when the background turbidity is 50 NTU

or less, or have more than a 10 percent increase in turbidity 

when the background turbidity is more than 50 NTU.

Class B Waters - Turbidity shall not exceed 5 NTU over 

background turbidity when the background turbidity is 50 NTU

or less, or have more than a 20 percent increase in turbidity 

when the background turbidity is more than 50 NTU.

Lake Class - No turbidity increase over 5 NTU over 

background conditions.

NARRATIVE STANDARD ONLY

Makah Tribe 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/makah.p

df

TURBIDITY

Freshwater Aquatic Life - Turbidity shall not exceed (i) 5 NTU

over background when the background is 50 NTU or less; or 

(ii) A 10 percent increase in turbidity when the background 

turbidity is more than 50 NTU.

Marine Aquatic Life, for Extraordinary & Excellent Quality 

Waters - Turbidity shall not exceed: (i) 5 NTU over background 

when the background is 50 NTU or less; or (ii) Have more than 

a 10 percent increase in turbidity when the background 

turbidity is more than 50 NTU.

Marine Aquatic Life, for Good Quality Waters - Turbidity shall 

not exceed: (i)10 NTU over background when the background 

is 50 NTU or less; or (ii) A 20 percent increase in turbidity 

when the background turbidity is more than 50 NTU.

Recreation – No turbidity increase over 5 NTU

Narrative Standard: Nutrients or other substances from 

anthropogenic causes shall not be present in concentrations which will 

produce objectionable algal densities or nuisance aquatic vegetation, 

result in a dominance of nuisance species, result in acute toxicity to 

any aquatic biota or wildlife, adversely affect public health or safety, 

or otherwise cause nuisance conditions. 
above background conditions. 

Port Gamble 

S’Klallam Tribe 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/sklallam-10-

wqs.pdf

TURBIDITY

Domestic Water Supply - Turbidity shall not exceed 1 NTU

over natural background levels when the natural background 

turbidity is 10 NTU or have more than a 10 percent increase in 

turbidity when the natural background level is more than 10 

NTU. Natural background turbidity for implementing this 

criteria is to represent the 90th percentile value of the annual 

average turbidity. 

Aquatic Life Criteria - Turbidity shall not exceed 5 NTU over 

natural background levels when the natural background 

turbidity is 50 NTU or less, or have more than a 10 percent

increase in turbidity when the natural background level is more 

than 50 NTU. Natural background turbidity for implementing 

this criteria is to represent the 90th percentile value of the annual 

average turbidity. 

NARRATIVE STANDARD ONLY

Puyallup Tribe 

of Indians 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/puyallup

_10_wqs.pdf

TURBIDITY

High Quality Waters - Turbidity shall not exceed 5 NTU over 

background turbidity when the background turbidity is 50 NTU

or less, or have more than a 10 percent increase in turbidity 

when the background turbidity is more than 50 NTU.

Good/Fair Quality Waters - Turbidity shall not exceed 10 NTU

over background turbidity when the background turbidity is 50 

NTU or less, or have more than a 20 percent increase in 

turbidity when the background turbidity is more than 50 NTU.

Lakes - No turbidity increase over 5 NTU above background 

conditions.

NONE

Spokane Tribe 

http://www.epa.g

ov/waterscience/s

tandards/wqslibra

ry/tribes/spokane.

pdf NARRATIVE STANDARD ONLY

PHOSPHORUS

Nutrient Criteria for Lakes -

Trophic 

State

If 

Ambient 

TP 

Range of 

Lake is:

Then 

Criteria

Should 

be Set

Ultraoligotrop

hic

0-4 4 or less

Oligotro

phic 

>4-10 10 or 

less
Lower 

mesotrop

hic

>10-20 20 or 

less

Upper 

mesotrop

hic

>20-35 35 or 

less