05-29-2003 Bayport Expansion Review Committee Meeting

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. . e e (Memorial Tract) located just north of Highway 146 on Red Bluff, immediately adjacent to Armand Bayou Nature Center and Taylor Lake. Within this property, the POHA proposes to create 66.8 acres of emergent freshwater wetlands (more than 3.4: I compensation for impacted, jurisdictional wetlands) and the enhancement of more than 12 acres of existing wetland. The project will also preserve 23.7 acres of forested and shrub uplands and 71 acres of restored coastal prairie. In addition, a conservation easement will be imposed on the entire I 73.5-acre tract. This will preserve a sizeable block of diverse habitat that is upstream of Armand Bayou Nature Center, and within its watershed. The applicant believ~s that this permanent protection of 173.5 acres offsets the impacts to aquatic resources located at the Bayport Terminal site. A more detailed discussion of the plan is contained elsewhere. Storm Water Management and Treatment The project will include a variety of mitigative features to improve water quality. These include first flush capture a south terminal retention pond, inlet treatment units, and high impact area treatment. These are described below. 10. First Flush - POHA is currently regulated for storm water discharges under the Multi-Sector Stormwater General Permit (MSGP) for Industrial Discharges and the Municipal Separate Storm Sewer System (MS4). The primary areas of concern under the MSGP for SIC 4491 (Water Transportation) are four metals (aluminum, zinc, lead and uranium). Experience at the existing Barbors Cut Container Terminal has revealed that these metals are primarily attached to Total Suspended Solids (TSS). To facilitate the capture of TSS, the applicant will capture the first inch of rainfall into a holding pond, as shown in the master plan drawing. This will allow the TSS to be retained in the pond, decreasing the discharge of sediments into the Bayport Ship Channel and Pine Gulley. 11. South Terminal Retention Pond - The loss of infiltration resulting from the concrete surfacing of the site would result in an increased rate of storm water discharge to Pine Gulley. To maintain the undeveloped discharge rate after project construction, the applicant will install a retention pond in addition to the first flush pond. The function of this structure is to capture and hold stormwater in excess of the first inch and release it slowly. The delayed release of stormwater will prevent increased flooding or disruption of the Pine Gulley ecosystem. To further enhance water quality fimctions, the POHA plans to create a meandering channel in the bottom of the South Terminal Retention Pond with fringe planting of low bio-mass wetland plant species, such as spikerush, which will grow to cover the entire 12-15 acre pond bottom. To discourage excess biomass build-up, the pond bottom will be mowed once annually, while the sides will be mowed 3-4 times per year to prevent loss of capacity. 12. Inlet Treatment Units and High Area ImDact Treatment - The areas with the highest likelihood of contributing contaminants to stormwater are the Maintenance Facility, RTG Maintenance Areas, and the Equipment Parking Areas. These areas will have isolated drainage Port of Houston Authority No. 21520(Revised) ...Iveston Bay. along the Bayport Ship Channel. Wy of Pasadena. Harris County, Texas. Attachment 1. Sheet 3 of ~(Revised May 2003) - 3 - 5/6/03