Stormwater Pollution Prevention Plan - Phoenix Sky Harbor ...

Non-mining MSGP 2010 General Permit
8.Q.6 Sector-Specific Benchmarks. (See also Part 6.)
Table 8.Q-1
Subsector
(Facility discharges may be subject to
Parameter
requirements for more than one
sector/subsector)
Subsector Q1. Water Transportation Facilities Total Aluminum
(SIC 4412-4499)
Total Iron
Total Lead 1
Total Zinc 1
Benchmark Monitoring
Concentration
0.75 mg/L
1.0 mg/L
Hardness Dependent
Hardness Dependent
1 The benchmark values of some metals are dependent on water hardness. For these parameters,
permittees must determine the hardness of the receiving water (see Appendix D, “Calculating Hardness
in Receiving Waters for Hardness Dependent Metals,” for methodology), in accordance with Part 6.2.1.1,
to identify the applicable ‘hardness range’ for determining their benchmark value applicable to their
facility. The ranges occur in 25 mg/L increments. Hardness Dependent Benchmarks follow in the table
below:
Benchmark values based on hardness and receiving waterbody
Water Hardness Range
(mg/L)
For discharges to
perennial and
intermittent
waterbodies
Lead
(mg/L)
Zinc
(mg/L)
For discharges to
ephemeral
waterbodies
Lead
(mg/L)
Zinc
(mg/L)
0-25 0.014 0.0362 0.0293 0.344
25-50 0.030 0.0651 0.0636 0.618
50-75 0.047 0.0918 0.0995 0.871
75-100 0.065 0.1170 0.1363 1.112
100-125 0.082 0.1417 0.1736 1.343
125-150 0.100 0.1652 0.2113 1.568
150-175 0.118 0.1883 0.2492 1.787
175-200 0.136 0.2108 0.2873 2.001
200-225 0.154 0.2329 0.3255 2.211
225-250 0.172 0.2547 0.3637 2.417
250-275 0.190 0.2761 0.4020 2.620
275-300 0.209 0.2972 0.4402 2.821
300-325 0.227 0.3181 0.4784 3.019
325-350 0.245 0.3387 0.5166 3.214
350-375 0.263 0.3591 0.5547 3.408
375-400 0.281 0.3793 0.5927 3.599
Stormwater Discharges Associated with Industrial Activity – Sector Q 71