1975-01-20 Regular Meeting - Laserfiche WebLink

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~ • • t ~- Section II The Environmental Impact of the Proposed Action Existin Environmental Conditions - The City of La Porte is situated in the exas Gulf Coast P ain, the surface of which is relatively flat, sloping to the Southeast at 1° - 2°. The surface is altered occasionally by under- lying salt domes which cause the land surface in the immediate area to rise .into rolling hills. The soils are predominately sand and clay of a depository nature. Water bearing sands are found at varying depths with shallowest generally transporting non potable, brackish waters. At least two potable water bearing sands exist, the lower Alta Loma at about 450 feet and the Lissie at about 600 feet. No significant mineral deposits or rocks are found other than the previously mentioned salt domes. There are some fossil shellfish to be found and traces of other small prehistoric sea creatures (clams, urchins, etc.). Soil erosion is generally not a problem due to the flatness of the land. No caves or other such formations are known to exist. Local subsidence which has become a well known problem in this area is causing a multitude of faults to be revealed throughout the region. The only local natural body of water involved is Galveston Bay which has a water quality equal to or better than the following: BOD - 4.82 ppm Nitrates - 0.16 ppm DO - 7.5 ppm Coliforms - <'2872 ppm Sulfates - 490 ppm Fecal Coliforms - 387.4 ppm VSS - 21.82 Total Phosphorus - 3.3 ppm TSS - 79.92 Big Island Slough and Little Cedar Bayou are two natural waterways in the area, but neither normally carries water except storm runoff in times of rain. Big Island Slough terminates in Clear Creek and Little Cedar Bayou joins Galveston Bay. Both waterways are subject to tidal action in the lower reaches. Big Island Slough is the discharge route for wastewater from the Fairmont Park plant which will be abandoned as a part of this project. Little Cedar Bayou is the discharge waterway for the main La Porte plant and will remain so for the enlarged plant which this project proposes. The climatic conditions in the City of La Porte are typical of any Texas Gulf Coast area. Prevailing winds are from the South and Southeast except in January when frequent passages of high pressure areas bring northerly winds. The yearly average temperatures range from about 78.8° F to 57.2° F with extremes reaching 101° F and 19° F. The average annual rainfall is 46.9 inches with extremes reaching as high as 72.86 inches per year and down to 17.66 inches per year. _. f.~ .. _. ,..,_..__., . -_ - _ . ,..~..