1. Dissolved Oxygen.

a. Shall not be less than 6.0 mg/l in cold water fisheries and not less than 5.0 mg/l

in warm water fisheries. Where natural background conditions are lower, DO shall

not be less than natural background conditions. Natural seasonal and daily variations

that are necessary to protect existing and designated uses shall be maintained.

2. Temperature.

a. Shall not exceed 68°F (20°C) based on the mean of the daily maximum

temperature over a seven day period in cold water fisheries, unless naturally

occurring. Where a reproducing cold water aquatic community exists at a naturally

occurring higher temperature, the temperature necessary to protect the community

shall not be exceeded and the natural daily and seasonal temperature fluctuations

necessary to protect the community shall be maintained. Temperature shall not

exceed 83°F (28.3°C) in warm water fisheries. The rise in temperature due to a

discharge shall not exceed 3°F (1.7°0C) in rivers and streams designated as cold

water fisheries nor 5°F (2.8°C) in rivers and streams designated as warm water

fisheries (based on the minimum expected flow for the month); in lakes and ponds

the rise shall not exceed 3°F (1.7°0C) in the epilimnion (based on the monthly

average of maximum daily temperature);

b. natural seasonal and daily variations that are necessary to protect existing and

designated uses shall be maintained. There shall be no changes from natural

background conditions that would impair any use assigned to this Class, including

those conditions necessary to protect normal species diversity, successful migration,

reproductive functions or growth of aquatic organisms;

c. alternative effluent limitations established in connection with a variance for a

thermal discharge issued under 33 U.S.C. § 1251 (FWPCA, § 316(a)) and 314 CMR

3.00 are in compliance with 314 CMR 4.00. As required by 33 U.S.C.§1251

(FWPCA, § 316(a)) and 314 CMR 3.00, for permit and variance renewal, the

applicant must demonstrate that alternative effluent limitations continue to comply

with the variance standard for thermal discharges; and

d. in the case of a cooling water intake structure (CWIS) regulated by EPA under

33 U.S.C. §1251 (FWPCA § 316(b)), the Department has the authority under 33

U.S.C. § 1251 (FWPCA §401), M.G.L. c. 21, §§ 26 through 53 and 314 CMR 3.00

to condition the CWIS to assure compliance of the withdrawal activity with 314

CMR 4.00, including, but not limited to, compliance with narrative and numerical

criteria and protection of existing and designated uses.

3. pH. Shall be in the range of 6.5 through 8.3 standard units and not more than 0.5

units outside of the natural background range. There shall be no change from natural

background conditions that would impair any use assigned to this Class.

4. Bacteria.

a. At bathing beaches as defined by the Massachusetts Department of Public Health

in 105 CMR 445.010: where E. coli is the chosen indicator, the geometric mean of

the five most recent samples taken during the same bathing season shall not exceed

126 colonies per 100 ml and no single sample taken during the bathing season shall

exceed 235 colonies per 100 ml; alternatively, where enterococci are the chosen

indicator, the geometric mean of the five most recent samples taken during the same

bathing season shall not exceed 33 colonies per 100 ml and no single sample taken

during the bathing season shall exceed 61 colonies per 100 ml;

b. for other waters and, during the non bathing season, for waters at bathing beaches

as defined by the Massachusetts Department of Public Health in 105 CMR 445.010:

the geometric mean of all E. coli samples taken within the most recent six months

shall not exceed 126 colonies per 100 ml typically based on a minimum of five

samples and no single sample shall exceed 235 colonies per 100 ml; alternatively, the

geometric mean of all enterococci samples taken within the most recent six months

shall not exceed 33 colonies per 100 ml typically based on a minimum of five

samples and no single sample shall exceed 61 colonies per 100 ml. These criteria

may be applied on a seasonal basis at the discretion of the Department; and

c. consistent with Massachusetts Department of Public Health regulations for

bathing beaches, the single sample maximum values in the primary contact bacteria

criteria in 314 CMR 4.05(3)(b)4.a. and 4.05(3)(b)4.b. also are for use in the context

of notification and closure decisions.

5. Solids. These waters shall be free from floating, suspended and settleable solids in

concentrations and combinations that would impair any use assigned to this Class, that

would cause aesthetically objectionable conditions, or that would impair the benthic biota

or degrade the chemical composition of the bottom.

6. Color and Turbidity. These waters shall be free from color and turbidity in

concentrations or combinations that are aesthetically objectionable or would impair any

use assigned to this Class.

7. Oil and Grease. These waters shall be free from oil, grease and petrochemicals that

produce a visible film on the surface of the water, impart an oily taste to the water or an

oily or other undesirable taste to the edible portions of aquatic life, coat the banks or

bottom of the water course, or are deleterious or become toxic to aquatic life.

8. Taste and Odor. None in such concentrations or combinations that are aesthetically

objectionable, that would impair any use assigned to this Class, or that would cause

tainting or undesirable flavors in the edible portions of aquatic life.