In order to prepare a SWP3 that includes batch plant operations, the TPDES Permit TXR150000 Part II.A.2 states the following:
“Construction support activities authorized under this general permit are not commercial operations, and do not serve multiple unrelated construction projects. Discharges of stormwater runoff from construction support activities may be authorized under this general permit, provided that the following conditions are met:
the activities are located within one (1) mile from the boundary of the permitted construction site and directly support the construction activity;
a SWP3 is developed for the permitted construction site according to the provisions of this general permit, and includes appropriate controls and measures to reduce erosion and discharge of pollutants in stormwater runoff from the construction support activities; and
the construction support activities either do not operate beyond the completion date of the construction activity or, at the time that they do, are authorized under separate Texas Pollutant Discharge Elimination System (TPDES) authorization.”
If the plant site meets the requirements above, pursuant to the Permit’s provision in Part III - “Individual operators at a site may develop separate SWP3s that cover only their portion of the project, provided reference is made to the other operators at the site. “, a SWP3 can be generated specifically for the paving operations on the site. The total area to be paved along with the area of the plant site will constitute the SWP3’s disturbed area. The plant site will be classified as a “Construction Support Activity” within the SWP3. As such, it will not require separate permitting under TXR050000. It must be inspected along with the paving operations. The plant site will require effluent testing of discharge as required by TXR150000 Section A:
“When discharge occurs. Sampling is required within the first 30 minutes of discharge. If it is not practicable to take the sample, or to complete the sampling, within the first 30 minutes, sampling must be completed within the first hour of discharge. If sampling is not completed within the first 30 minutes of discharge, the reason must be documented and attached to all required reports and records of the sampling activity.
Sampling must be conducted at least once during each of the following periods. The first sample must be collected during the first full quarter that a stormwater discharge occurs from a concrete batch plant authorized under this general permit.
January through March; April through June; July through September; October through December.
For projects lasting less than one full quarter, a minimum of one sample shall be collected, provided that a stormwater discharge occurred at least once following submission of the NOI or following the date that automatic authorization was obtained under Section II.E.2., and prior to terminating coverage.A grab sample shall be collected from the stormwater discharge resulting from a storm event that is at least 0.1 inches of measured precipitation that occurs at least 72 hours from the previously measurable storm event. The sample shall be collected downstream of the concrete batch plant, and where the discharge exits any BMPs utilized to handle the runoff from the batch plant, prior to commingling with any other water authorized under this general permit.“
In an effort to reduce the likelihood of discharge from the batch plant site, the erosion control plan will show the creation of an earthen perimeter berm 18”-24” tall around the entire plant site. The erosion control plan will show a minimum of one stabilized construction entrance at the plant site to provide for traffic egress.
In order to terminate Permit coverage for this SWP3, all paving operations will need to have been completed, the entrance and earthen berm will need to be removed and the area disturbed at the plant site will need to reach final stabilization.