1. (1) industrial water supplies after reasonable treatment;

   1. (i) maintenance of resident fish and other aquatic life;
   2. (ii) passage of anadromous fish;

   3. (iii) wildlife;

      (3)

   4. (i) recreation-secondary contact above R.M. 81.8; and
   5. (ii) recreation below R.M. 81.8; and

   (2)

2. (4) navigation.

   (c) Stream quality objectives.

3. (1) Dissolved oxygen:

   1. (i) 24-hour average concentration shall not be less than 3.5 mg/l; and
   2. (ii) during the periods from April 1st to June 15th, and September 16th to December 31st, the dissolved oxygen shall not have a seasonal average of less than 6.5 mg/l.

4. (2) Temperature. Shall not exceed:

   1. (i) 5°F (2.8°C) above the average 24-hour temperature gradient displayed during the 1961-66 period; or
   2. (ii) a maximum of 86°F (30.0°C), whichever is less. (See section 861.12[f][3] of this Title.)
5. (3) pH. Between 6.5 and 8.5 inclusive, unless outside this range due to natural conditions.
6. (4) Phenols. Maximum 0.02 mg/l, unless exceeded due to natural conditions.
7. (5) Threshold odor number. Not to exceed 24 at 60°C.
8. (6) Synthetic detergents (M.B.A.S.). Maximum 30-day average 1.0 mg/l.

9. (7) Radioactivity:

   1. (i) alpha emitters, maximum 3 pc/l (picocuries per liter);
   2. (ii) beta emitters, maximum 1,000 pc/l.

10. (8) Bacteria.

    1. (i) Fecal Coliform.

       1. (a) Above R.M. 81.8 maximum geometric average 770 per 100 milliliters.
       2. (b) Below R.M. 81.8 maximum geometric average 200 per 100 milliliters.

    2. (ii) Enterococcus.

       1. (a) Above R.M. 81.8 maximum geometric average 88 per 100 milliliters.
       2. (b) Below R.M. 81.8 maximum geometric average 33 per 100 milliliters.
11. (9) Total dissolved solids. Not to exceed 133 percent of background.

12. (10) Turbidity. Unless exceeded due to natural conditions:

    1. (i) maximum 30-day average 40 units; and
    2. (ii) maximum 150 units.
13. (11) Alkalinity. Between 20 and 120 mg/l.

14. (12) Toxic pollutants.

    1. (i) Applicable criteria to protect the taste and odor of ingested water and fish are presented in Tables 4 (section 860.30(c)(11).
    2. (ii) Applicable freshwater stream quality objectives for the protection of aquatic life are presented in Table 5 (section 860.30(c)(11).

    3. (iii) Applicable freshwater stream quality objectives for the protection of human health are presented in Tables 6 and 7 (section 860.30(c)(11).

       (d) Effluent quality requirements.

15. (1) All discharges shall meet the effluent quality requirements of this Part.
16. (2) the carbonaceous oxygen demand from all outfalls in the zone (exclusive of storm water bypass) shall not exceed that assigned by commission regulations.

(a) Description.

Zone 4 is that part of the Delaware River extending from RM 95.0 to RM 78.8, the Pennsylvania-Delaware boundary line, including the tidal portions of the tributaries thereof.

(b) Water uses to be protected.

The quality of zone 4 waters shall be maintained in a safe and satisfactory condition for the following uses: