The Texas Commission on Environmental Quality (TCEQ) has proposed to revise the current TPDES Multi Sector General Permit (MSGP) TXR050000, issued August 14, 2011 and expires on August 14, 2016. This permit authorizes the discharge of stormwater associated with industrial activity. The revised draft MSGP specifies which facilities must obtain permit coverage, which are eligible for exclusion from permit requirements, which may be automatically authorized, and which may be required to obtain individual permit coverage.

The principal changes to the existing MSGP include:

A. Changed the Standard Industrial Classification (SIC) code and sector format in Part II Section A to clarify what facilities are regulated under the general permit by adding more details to the existing SIC codes and industrial activity descriptions.

B. Added narrative and numeric effluent limitations guidelines under Part V, Sector S (Air Transportation) to include deicing requirements based on final federal Effluent Limitation Guidelines at 40 Code of Federal Regulations (CFR) Part 449 for airport and airplane deicing operations.

C. Changes to benchmark values and sampling:

  •  Lowered Ammonia Nitrogen value from 2.5 milligrams per Liter (mg/L) to 1.7 mg/L.
  •  Lowered Total Suspended Solids (TSS) values from 100 mg/L to 50 mg/L for sector A (SIC codes 2426 – 2499), sector C (SIC codes 2873 – 2879), sector F (SIC codes 3321 -3325), and sector H (SIC codes 1221 – 1241).
  • Lowered Biochemical Oxygen Demand (BOD) values from 30 mg/L to 20 mg/L for Sector T (Activity code TW)
  • Added language to Part IV, Section B.1.(a) clarifying the sampling requirements for the waiver option for benchmark sampling during Years 3 and 4. If sampling during Years 1 and 2 demonstrates that the annual average result for all benchmark parameters is below the benchmark level for the regulated sector, then permitees can waiver out of sampling for Years 3 and 4.

D. Added SIC code 7699 (Ship scaling services not done at a ship yard; Motorboat repair and maintenance services) to Sector R (Ship and Boat Building or Repairing Yards) .

E. Clarified permit language in Part V, Sector P (Land Transportation and Warehousing) and Sector I (Oil and Gas Extraction Facilities)

G. Clarified permit language in Part II, Section C.1(a) for above ground storage tanks (ASTs) requirements.

H. Added language to Part III, Section D.1 (c) to clarify how permittees should document zero rainfall totals, or no rain for sampling requirements.

I. Added clarification to the section “Impaired Water Bodies and Total Maximum Daily Load Requirements” to address when discharges are considered discharging to an impaired water body.

Caltha LLP provides technical support to Texas facilities to comply with State general stormwater discharge permit, and other regulatory compliance issues.

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