40 CFR § 471.41 - Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).
Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations for the process operations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT):
(a) Rolling spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.
(b) Rolling spent emulsions.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(c) Drawing spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.
(d) Drawing spent emulsions.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(e) Drawing spent soap solutions.
Subpart D—BPT
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
|---|---|---|
| mg/off-kg (pounds per million off-pounds) of precious metals drawn with soap solutions | ||
| Cadmium | 0.001 | 0.0005 |
| Copper | 0.006 | 0.003 |
| Cyanide | 0.0009 | 0.0004 |
| Silver | 0.001 | 0.0006 |
| Oil and grease | 0.063 | 0.038 |
| TSS | 0.128 | 0.061 |
| pH | ( 1) | ( 1) |
1 Within the range of 7.5 to 10.0 at all times.
(f) Metal powder production wet atomization wastewater.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(g) Heat treatment contact cooling water.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(h) Semi-continuous or continuous casting contact cooling water.
Subpart D—BPT
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
|---|---|---|
| mg/off-kg (pounds per million off-pounds) of precious metals cast by the semi-continuous or continuous method | ||
| Cadmium | 3.50 | 1.55 |
| Copper | 19.6 | 10.3 |
| Cyanide | 2.99 | 1.24 |
| Silver | 4.23 | 1.75 |
| Oil and grease | 206 | 124 |
| TSS | 423 | 209 |
| pH | ( 1) | ( 1) |
1 Within the range of 7.5 to 10.0 at all times.
(i) Stationary casting contact cooling water—subpart D—BPT. There shall be no discharge of process wastewater pollutants.
(j) Direct chill casting contact cooling water.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(k) Shot casting contact cooling water.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(l) Wet air pollution control scrubber blowdown—subpart D—BPT. There shall be no discharge of process wastewater pollutants.
(m) Pressure bonding contact cooling water.
Subpart D—BPT
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
|---|---|---|
| mg/off-kg (pounds per million off-pounds) of precious metals and base metal pressure bonded | ||
| Cadmium | 0.029 | 0.013 |
| Copper | 0.159 | 0.084 |
| Cyanide | 0.024 | 0.010 |
| Silver | 0.034 | 0.014 |
| Oil and grease | 1.67 | 1.00 |
| TSS | 3.43 | 1.63 |
| pH | ( 1) | ( 1) |
1 Within the range of 7.5 to 10.0 at all times.
(n) Surface treatment spent baths.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(o) Surface treatment rinse.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(p) Alkaline cleaning spent baths.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(q) Alkaline cleaning rinse.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(r) Alkaline cleaning prebonding wastewater.
Subpart D—BPT
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
|---|---|---|
| mg/off-kg (pounds per million off-pounds) of precious metals and base metal cleaned prior to bonding | ||
| Cadmium | 3.95 | 1.74 |
| Copper | 22.1 | 11.6 |
| Cyanide | 3.37 | 1.39 |
| Silver | 4.76 | 1.97 |
| Oil and grease | 232 | 139 |
| TSS | 476 | 226 |
| pH | ( 1) | ( 1) |
1 Within the range of 7.5 to 10.0 at all times.
(s) Tumbling or burnishing wastewater.
Subpart D—BPT
1 Within the range of 7.5 to 10.0 at all times.
(t) Sawing or grinding spent neat oils—subpart D—BPT. There shall be no discharge of process wastewater pollutants.
(u) Sawing or grinding spent emulsions.
Subpart D—BPT
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
|---|---|---|
| mg/off-kg (pounds per million off-pounds) of precious metals sawed or ground with emulsions | ||
| Cadmium | 0.032 | 0.014 |
| Copper | 0.178 | 0.094 |
| Cyanide | 0.027 | 0.011 |
| Silver | 0.039 | 0.016 |
| Oil and grease | 1.87 | 1.12 |
| TSS | 3.83 | 1.82 |
| pH | ( 1) | ( 1) |
1 Within the range of 7.5 to 10.0 at all times.
(v) Degreasing spent solvents—subpart D—BPT. There shall be no discharge of process wastewater pollutants.