§ 6.0. Environmental requirements section.

Texas Construction General Permit (CGP)

Construction activities that discharge stormwater runoff into or adjacent to any surface water of the state are regulated by the State of Texas under the construction general permit (CGP) (TXR150000). The governing agency is the Texas Commission on Environmental Quality (TCEQ). Construction activities are regulated according to the area of land disturbed.

Large construction activities:

For sites that disturb five or more acres, or are part of a larger common plan of development that will disturb five or more acres, and meet the definition of an operator, the following applies:

1.

Prepare and implement a stormwater pollution prevention plan (SW3P).

2.

Post a site notice.

3.

Submit a copy of the site notice to the MS4 operator.

For sites that disturb five or more acres, and meet the definition of a primary operator, the following applies:

1.

Prepare and implement a SW3P.

2.

Submit a notice of intent (NOI) to TCEQ.

3.

Post the NOI and site notice.

4.

Submit a copy of the NOI to MS4 operator

Small construction activities:

For sites that disturb at least one but less than five acres, or are part of a larger common plan of development that will disturb at least one, but less than five acres and meet the definition of an operator, the following applies:

1.

Prepare and implement a SW3P.

2.

Post a site notice.

3.

Submit a copy of the site notice to the MS4 operator.

Sites that disturb less than one acre and that are not part of a larger common plan of development that would disturb one or more acres, are not required to have coverage under the general permit. Refer to the General Permit definitions for Operator and Primary Operator. Additional information on the Texas Construction General Permit can be found at the following link: http://www.tceq.texas.gov/permitting/stormwater/

Storm Water Pollution Prevention Plan (SW3P).

One of the requirements of the construction general permit is to develop an SW3P in accordance with CGP and the SW3P guidance policy for the Town of Little Elm. The purpose of the SW3P is to provide guidelines for minimizing sediment and other pollutants that may originate on the site, from flowing into municipal storm systems, or jurisdictional waters during construction. The plan must also address the principal activities known to disturb significant amounts of ground surface during construction. The stormwater management controls included in the SW3P should focus on providing control of pollutant discharges with practical approaches that use readily available techniques, expertise, materials, and equipment. The SW3P must be implemented prior to the start of construction activity.

Construction Controls.

Structural and non-structural controls may be used for controlling pollutants for stormwater discharges from small and large sites. Structural controls shall comply with details and specifications in the latest edition of the NCTCOG iSWM technical manual and these standards. When the NCTCOG Manual and these standards are in conflict, these standards shall govern. The following are acceptable temporary controls for use during construction:

Non-Structural

Minimizing the area of disturbance
Preserving existing vegetation

Structural

Silt fence
Inlet protection
Rock check dams
Stabilized construction entrances
Sediment traps
Vegetated buffer strips
Temporary detention structure
Rock check dams
Hydromulch

Suggested construction controls can be found on the NCTCOG iSWM website. It is the responsibility of the design engineer to select and design appropriate construction controls for each site. If the most appropriate control is not shown in the iSWM technical manual, the design engineer shall submit calculations and references for design of the control to the Department of Engineering Services for review and approval.

Waste and Hazardous Material Controls.

Covered containers shall be provided for waste construction materials and daily trash. Hazardous materials shall be stored in a manner that prevents contact with rainfall and runoff. Onsite fuel tanks and other containers of motor vehicle fluids shall be placed in a bermed area with a liquidtight liner or be provided with other secondary containment and spill prevention controls. The SW3P shall require federal, state and local reporting of any spills and releases of hazardous materials greater than the regulated reportable quantity (RQ) and reporting to engineering services of all spills and releases to the storm drainage system.

Temporary Stabilization.

A.

Portions of a site that have been disturbed, but where no work will occur for more than 21 days shall be temporarily stabilized as soon as practicable, and no later than 14 days, except when precluded by seasonal arid conditions, or prolonged drought.

B.

Temporary stabilization shall consist of providing a protective cover, designed to reduce erosion on disturbed areas. Temporary stabilization may be achieved using temporary seeding, soil retention blankets, hydro-mulches and other techniques that cover 100 percent of the disturbed areas until either final stabilization can be achieved or until further construction activities take place.

C.

Perimeter controls such as silt fence, vegetated buffer strips or other similar perimeter controls are intended to act as controls when stabilization has not occurred. Perimeter controls may remain in place during temporary stabilization.

Final Stabilization.

Final stabilization consists of soil cover such as vegetation, geo-textiles, mulch, rock, or placement of pavement. For stabilizing vegetated drainageways, sod or seeded soil retention blankets shall be used. Hydromulch will not be allowed in vegetated swales, channels or other drainageways. The plan for final stabilization shall be coordinated with permanent controls in the SWMP and with the landscaping plan, if applicable.

Notice of Intent (NOI).

If applicable, copies of the NOI shall be sent to the public works department at least two days prior to construction. The NOI may be emailed to [e-mail].

TCEQ Site Notice.

A signed copy of the construction site notice shall be posted at the construction site in a location where it is readily viewed by the general public during all construction activity.

Notice of Termination (NOT).

All parties that submitted a NOI shall submit a NOT within 30 days after final stabilization is established. When the owner of a residential subdivision transfers ownership of individual lots to builders before final stabilization is achieved, the SW3P shall include controls for each individual lot in lieu of final stabilization. These controls shall consist of stabilization of the right-of-way and placement of structural controls at the low point of each individual lot or equivalent measures to retain soil on each lot during construction. All temporary controls must be removed prior to submitting the NOT. Additionally, the builder must submit a valid NOI before an NOT can be submitted by the owner.

Inspection and Maintenance during Construction.

1.

The owner shall construct all controls required by the SW3P. The owner shall have qualified personnel inspect the controls every seven days with no additional inspections after rain events. An alternative method may be used as long as it is in accordance with the CGP.

2.

Certified inspection reports shall be retained as part of the SW3P. Within seven days of the inspection, controls identified as damaged or deteriorated shall be repaired or replaced, as appropriate. Controls shall also be routinely cleaned to maintain adequate capacity.

3.

Changes or additions shall be made to the controls within seven days to prevent discharges from the site. The owner shall implement procedures to remove discharged soil from all portions of the storm drainage system including streets, gutters, inlets, storm drain, channels, creeks, ponds, etc.

4.

Notes requiring the inspection and maintenance shall be placed on SW3P drawings. The SW3P shall identify the responsible party for inspecting and maintaining each control. If no party is identified, each owner and operator that submitted a NOI for the site shall be fully responsible for implementing all requirements of the SW3P.

Construction and Maintenance.

The owner shall submit an erosion control plan and site layout for each major phase of the project. These phases, at a minimum, shall include:

1.

Initial grading and utility construction.

2.

Street and other pavement construction.

3.

Post pavement construction.

4.

Final acceptance to stabilization.

The owner shall construct all permanent controls and is responsible for maintenance of the controls. When the control falls within a drainage easement, the plat or separate instrument dedicating the easement shall include a statement of the owner's responsibility for maintenance.