§ 422.42 — Effluent limitations and guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

40 CFR § 422.42

• Title: Title 40: Protection of Environment
• Part: Part 422: Phosphate Manufacturing Point Source Category
• Source: eCFR (current through Apr 10, 2026)

Text

§ 422.42 Effluent limitations and guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

(a) Subject to the provisions of paragraphs (b), (c) and (d) of this section, the following limitations establish the quantity or quality of pollutants or pollutant properties, controlled by this section, which may be discharged by a point source subject to the provisions of this subpart after application of the best practicable control technology currently available: There shall be no discharge of process waste water pollutants to navigable waters.

(b) Process waste water pollutants from a cooling water recirculation system designed, constructed and operated to maintain a surge capacity equal to the runoff from the 10-year, 24-hour rainfall event may be discharged, after treatment to the standards set forth in paragraph (c) of this section, whenever chronic or catastrophic precipitation events cause the water level in the pond to rise into the surge capacity. Process waste water must be treated and discharged whenever the water level equals or exceeds the mid point of the surge capacity.

(c) The concentration of pollutants discharged in process waste water pursuant to the limitations of paragraph (b) of this section shall not exceed the values listed in the following table:

[Milligrams per liter]

Effluent characteristic	Effluent limitations
	Maximum for any 1 day	Average of daily values for 30 consecutive days shall not exceed—
Total phosphorus (as P)	105	35
Fluoride (as F)	75	25
TSS	150	50
pH	(1)	(1)
1 Within the range 6.0 to 9.5.

The total suspended solid limitation set forth in this paragraph shall be waived for process wastewater from a calcium sulfate storage pile runoff facility, operated separately or in combination with a water recirculation system, which is chemically treated and then clarified or settled to meet the other pollutant limitations set forth in this paragraph.

(d) The concentration of pollutants discharged in contaminated nonprocess wastewater shall not exceed the values listed in the following table:

[Milligrams per liter]

Effluent characteristic	Effluent limitations
	Maximum for any 1 day	Average of daily values for 30 consecutive days shall not exceed—
Total phosphorus (as P)	105	35
Fluoride (as F)	75	25
pH	(1)	(1)
1 Within the range 6.0 to 9.5.