Central Texas project meets storm water compliance requirements to mitigate runoff
Central Texas cities are expanding and sprawling at one of the fastest rates in the nation. There are many new residential communities, commercial buildings and infrastructure improvements needed to facilitate this urban growth. Unfortunately, a byproduct of abounding construction is pollution, especially pollution related to the storm water runoff of construction debris and dirt. Because of this, storm water awareness and water quality goals have become larger components of developmental strategies. Local, state and national level environmental agencies have continued to crack down on storm water policy, and storm water permittees are continuing to learn the best and most efficient ways to stay compliant.
Planning & Permitting
The project site for a new elementary school in Central Texas is approximately 14 acres and necessitates gas and electric installation, consisting of both overhead and underground utility work. When this land type is set to be developed, there are many steps that need to occur before utility installation can begin, including planning, development, permitting and more. The project site's developer must have its own set of permits, including storm water, allowing it to break ground and initiate development. Once the site has been cleared and graded, and perimeter sediment and erosion control measures are installed, utility installation can commence. For this project, the chosen best management practices (BMPs) included silt fence on the downslope portion of the project and gravel filter bags at the storm drain inlets.
Utility installations often will cover most of the site and will tie into existing infrastructure lines (i.e., underground gas and/or electrical lines and overhead electrical lines). To connect old and new infrastructure, the installer may need to conduct work outside of the development’s perimeter controls off site and access the tie-in locations. In the case of this elementary school, work off site and outside the perimeter of the common plan of development is necessary and requires that the utility installer be held liable for designing BMPs to address storm water permit concerns not addressed by the developer’s BMPs. These additional BMPs must contain all offsite discharges and address the final stabilization measures of the offsite area of impact to reach the required 70% final stabilization.
The elementary school project, like all utility installations, has a distinct set of specifications. Each site offers its own set of challenges and uniqueness related to topography and other natural resource concerns. For these reasons, the utility work usually is carried out by a specialized contractor who is proficient in the installation of utility lines. However, the utility provider has the final say on the correctness and completion of installed utility lines, as well as the ability to modify their plans to best fit the site conditions. This hiring and firing power gives the utility provider (the owner) the status of an operator. Per the permit, an operator has control of the plans, specifications, and/or day-to-day control of the construction site. Further, an operator ensures compliance with a storm water pollution prevention plan (SWPPP) and is required to maintain overall compliance with the Texas Pollutant Discharge Elimination System (TPDES) program. As an operator with control over plans and specifications, the utility provider must have its own set of storm water permits to conduct work, and the installer, acting as an operator with control over day-to-day operations, also must obtain permit coverage.
The utility provider starts with a review and assessment of the type of work that is planned for the site (i.e., gas, underground or overhead electrical, or both). A SWPPP then will be created, reviewed by the utility provider and the contractor, then approved. Once the SWPPP is approved, both operators must create the appropriate type of Notice of Intent permit: one for the utility provider and one for the contractor (if one will be used). Once permitting is completed and construction site notices posted, then installation work can begin. During construction, the permittees must ensure performance of weekly inspections of the project.
A typical onsite utility trench for gas and electric line installation was located within the developer’s footprint.
During site inspections, the inspector will look at the active work area and determine if any discharges are affecting a perimeter BMP controlled by the developer of the overall common plan. If so, then a corrective action is needed to rectify the issue. However, if a discharge from an activity related to utility work takes place but is contained within the developer’s designed BMPs and has not damaged the BMPs, then the discharge is controlled by the developer’s BMPs and no corrective action is required by the utility provider and its contractor. Once all utility work is complete, permit termination can be initiated by creation of a Notice of Termination (NOT) for the active TPDES and/or NPDES permits. The project is considered complete only if the area of impact has been returned to the original grade and operational control of the area has been returned to the developer, and/or all offsite impacts have achieved a 70% stabilization. After the NOT is filed and signed, permit guidelines require all records of site work to be kept for three years.
In the case of the elementary school project, the utility provider had specifications to install onsite gas, underground electric and overhead street lights. To do this, the provider had to tie in to offsite lines located across the street from the project entrance. An electric power pole was installed roughly 200 ft from the curb line for future powerline work. This power pole then was connected to an underground electricity line via a trench spanning the 200-ft distance. Simultaneously, onsite, the utility provider created underground electrical trenches to connect the school building to the local power grid and stub outs installed for streetlight installation. Once the onsite electric work was completed and all the trenches filled, stabilization was not necessary because the work was completed within the developer’s common plan of development. The developer prescribed final stabilization and was its responsibility.
The offsite trenches, however, needed to be backfilled and the 70% vegetative stabilization achieved. In this case, the utility provider also turned control of this portion of the project back to the developer. Because turning over offsite control was not customary, a discussion with the developer and acknowledgement of the responsibility was needed in writing before operators could file the NOT for the electric work. Once the permit was terminated, the displayed onsite permit signage was removed.
With electric work complete, it was time for the gas installation contractor to conduct their work. The onsite portion of work took place along some of the same trench areas as the electric work, so much of the same area was disturbed. The onsite work was completed free of issue and within days. The offsite work, however, was done through an underground bore that was placed in the same area of impact as the offsite electric work. The electric offsite area was controlled by the developer, but the gas work still was controlled by the utility provider. Even though this area was small, it still required stabilization as part of a larger common plan of development. Because this was the end of the utility providers work within the entire site, it was necessary to reach stabilization to remain compliant and terminate all permits for this project.
The work took place during drought conditions in Texas, and there are certain provisions in the TXR150000 permit for final stabilization in this arid climate. The gas contractor initially laid grass seed, but failed to apply sufficient water for stabilization. As an alternative way to reach final stabilization during the drought, the contractor opted to place wood mulch on top of the already laid grass seed. The mulch will hold water longer than regular sediment and allow the seeds to sprout once regular rain and watering cycles began. Once the mulch was installed and photos taken for documentation, the gas NOT permit was filed, gas permit signage was removed and the site was completed.
This project is a typical representation of the intricacies of the operator-contractor relationship and the ways that a utility provider approaches working on a construction site in central Texas. It can be complicated and sometimes frustrating, but communication is the best way to stay on top of potential issues and keep construction debris and dirt out of storm water.