Water and Sediment Quality Priority Problems
For the most part Galveston Bay has historically maintained good water quality, which can be attributed in good part to its characteristics. It is shallow, well mixed, well aerated and undergoes a total water exchange more than four times a year due to freshwater inflow and tidal action. However, difficult water and sediment challenges must be addressed if Galveston Bay is to remain healthy and productive.
Contaminated storm water runoff, or non-point source (NPS) pollution, remains the top water quality problem facing Galveston Bay. NPS pollution is transported to our waterways via rainfall runoff from diffuse, land-based sources such as businesses, industries, farms, roads, parking lots, septic tanks, marinas and residential yards. Indications are that non-point sources of pollutants have steadily increased to the present day as human population and associated urban development have increased.
 Even though non-point sources dominate pollutant loadings in many of our subwatersheds, point sources pose water and sediment quality problems. Point source pollution problems facing Galveston Bay include:
- sewage leaks, sewage bypasses, and sanitary sewer overflows to our storm sewers, ground water, and the bay's tributaries, resulting from subsidence and corrosion of cities' aging wastewater collection systems
- improperly treated discharges from some small utility districts' wastewater treatment plants where operation and maintenance problems persist
- illicit connections to storm sewers, either intentional or unintentional
The effects of non-point source and point source pollution on the estuary include:
- low dissolved oxygen in the bay's western, urbanized bayous from nutrients and other oxygen-demanding substances
- toxic contamination of water and sediment by metals and organic pollutants
- closure of about one-half of the bay's shellfish harvesting areas due to elevated fecal coliform bacteria contamination
As a result of this degradation, many of the bay's tributaries have been listed on the Texas Section 303(d) List.
See more information on priority problems related to Galveston Bay water and sediment quality in Chapter Six of The State of the Bay. See Solutions. |
