The City of Seguin (City) is proposing to construct a new, replacement effluent outfall for the Geronimo Creek Wastewater Treatment Plant. The City also proposes to abandon the existing outfall structure and existing pipeline in place. The proposed project will involve the extension of an existing 24 inch (in) (61 centimeters [cm]) wastewater treatment plant effluent line for a length of 535 feet (ft.) (163 meters [m]). The line will terminate at a new outfall structure located on the east bank of Geronimo Creek, approximately 260 ft. (79 m) from its confluence with the Guadalupe River. Two new manholes will be constructed along the line at major bends in the line. Line depths will range from 9 to 28 ft. (2.7 to 8.5 m). A 40 ft. (12.2 m) wide permanent easement is proposed for the line, along with a 30 ft. (9.1 m) wide temporary easementfor construction purposes. The extent of the outfallstructure should be fully within the 40 ft. (12.2 m) wide easement. The area of potential effect (APE) is defined as an area measuring 535 ft. (163 m) in length, and 70 ft. (21.3 m) in width for a total of 0.85 acres, and generally follows the eastern bank of Geronimo Creek.
The Texas Historical Commission (THC) reviewed the proposed development plans and determined that a cultural resource survey was necessary for this City proposed project as the area has potential for cultural resources. The City contracted with TRC Environmental Corporation (TRC) of Austin to conduct the intensive cultural resource survey of their proposed undertaking/APE.
TRC archeologists consulted the THC Archeological Sites Atlas (THC Atlas), a database that contains previously documented cultural resource sites and locations of previously conducted archeological surveys, prior to the field investigations. A 1 mi. (1.6 km) radius search around the APE revealed one previously recorded cultural resource site, 41GU21. This prehistoric site is on a high terrace just west of Geronimo Creek and has been extensively disturbed during modern housing construction and is considered ineligible for inclusion in the National Register of Historic Places (NRHP). No previous cultural resources surveys have been conducted in the vicinity of the APE. Southwest of the APE and beyond the 1 mi. (1.6 km) radius was a Texas Department of Transportation survey conducted in 2007 by Moore Consulting, Inc. along Farm-to-Market road 477. No cultural resources were recorded in that linear investigation.
On October 14 and 15, 2014, Mike Quigg, a TRC archeologists of the Planning, Permitting, and Licensing Practice of TRC’s office in Austin, conducted an intensive cultural resource survey along the 535 ft. (163 m) length of proposed APE. This included a 100 percent pedestrian survey, plus the mechanical excavation of four backhoe trenches (BT) within the APE to determine the presence/absence of any potential cultural resources within the APE. One deeply buried prehistoric site of potential significance was identified in two trenches (BTs 1 and 2) on the upper terrace along the APE. No cultural materials were recovered from two trenches (BTs 3 and 4) dug into the APE in the lower terrace. No historic structures were in the proposed APE.
TRC recommends avoidance of the potentially significant, deep stratified prehistoric site. If the site cannot be avoided then TRC recommends further testing to assess the sites significance, and the potential to yield significant information important in prehistory, either locally, regionally or nationally as per its legal obligations under existing state guidelines.
The City of Seguin reviewed the draft report, the archeological findings, and recommendations by TRC archeologists, and sought an alternate route for the proposed sewer line to avoid impact to cultural resource site 41GU168. The City and its engineers agreed to an alternate reroute satisfactory with the landowner that avoids the upper terrace The City of Seguin reviewed the draft report, the archeological findings, and recommendations by TRC archeologists, and sought an alternate route for the proposed sewer line to avoid impact to cultural resource site 41GU168. The City and its engineers agreed to an alternate reroute satisfactory with the landowner that avoids the upper terrace and the archeological site altogether. This proposed reroute successfully avoids and preserves deeply buried prehistoric site 41GU168 in place. TRC now recommends no further cultural resource investigation following the new proposed sewer line location
