Pollution Affecting Shellfish Harvesting In Galveston Bay Texas


         ENVIRONMENTAL PROTECTION AGENCY

              WATER QUALITY OFFICE
                    Report on
                                 \
    Pollution Affecting Shellfish Harvesting
                       in
              Calves ton Bay, Texas
                   Prepared by
Division of Field Investigations - Denver Center
                       and
              South Central Region
Denver, Colorado                   Dallas,  Texas

                   March 1971

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                        TABLE OF CONTENTS


Section                       Title

           LIST OF FIGURES .	,

           LIST OF TABLES  .......
   I       INTRODUCTION  .  .  .  .  	  .......        1

  II       SUMMARY AND CONCLUSIONS	        3

 III       RECOMMENDATIONS  .......  	  ....       11

  IV       DESCRIPTION OF AREA	  .       15

           A.  PHYSICAL DESCRIPTION	       15
           B.  CLIMATE	       16
           C.  HYDROLOGY	       17
           D.  POPULATION	       19
           E.  ECONOMY	       20
           F.  WATER USE	       21
               Municipal and  Industrial Water  Supply  ...       21
               Navigation	       23
               Recreation	       24
               Irrigation	,	       25
               Shellfish Harvesting  	       25

   V       WATER QUALITY	       29

           A.  APPLICABLE STANDARDS  	       29
           B.  COLIFORM	       31
           C.  HEAVY METALS AND PESTICIDES	       36
           D.  OIL AND PETROCHEMICAL RESIDUES	       40
           E.  DISSOLVED OXYGEN	       44
           F.  BIOCHEMICAL OXYGEN DEMAND  	       47

  VI       WASTE SOURCES .  „	       51
           A.  MUNICIPAL AND  DOMESTIC WASTE DISCHARGES  .  .       64
           B.  INDUSTRIAL WASTE DISCHARGES  	       65
           C.  OTHER SOURCES	       75

 VII       ECONOMIC IMPACT  OF POLLUTION  	       79

           A.  SHELLFISH AREAS  CLOSED BY  POLLUTION  ....       79
           B.  PRODUCTIVE SHELLFISH  BEDS IN CLOSED AREAS        81
           C.  ECONOMIC DAMAGES	       83

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                  TABLE OF CONTENTS (CONT'D)
Section                      Title
 VIII     WATER QUALITY IMPACT OF FUTURE DEVELOPMENTS  ...      87

          A.   HOUSTON WATER SUPPLY DIVERSION 	      87
          B.   CEDAR BAYOU POWER PLANT  	      90
          C.   MORGAN POINT DEEPWATER PORT  	      95
          BIBLIOGRAPHY  	      97

          APPENDICES

               A    APPLICABLE TEXAS WATER QUALITY
                      REQUIREMENTS FOR THE CALVESTON
                      BAY AREA AND THE PUBLIC HEALTH
                      SERVICE MANUAL "SANITATION OF
                      SHELLFISH GROWING AREAS"

               B    ODOR EVALUATION TEST PROCEDURES
                      AND RESULTS
                               11

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                         LIST OF FIGURES
Figure No.


   IV-1

    V-l


    V-2


    V-3


    V-4



    V-5



    V-6



    V-7



    V-8



    V-9



    V-10



    V-ll
           Title
Calves ton Bay Area

Water Quality Standards Zones
  in the Calves ton Bay Area

Calves ton Bay Study Sampling
  Stations and Classifications
  of Shellfish Harvesting Areas
Isolines of Median Coliform
  Concentrations, Calves ton Bay

Percent of Samples with Total
  Coliform Concentrations Greater
  Than 230/100 ml, Calves ton Bay

Isolines of Total Coliform Con-
  centrations - Galveston Bay -
  January 14, 1969

Isolines of Total Coliform Con-
  centrations - Galveston Bay -
  February 18, 1969

Isolines of Total Coliform Con-
  centrations - Galveston Bay -
  March 18, 1969

Isolines of Total Coliform Con-
  centrations - Galveston Bay -
  January 13, 1970

Isolines of Total Coliform Con-
  centrations - Galveston Bay -
  February 10, 1970

Isolines of Total Coliform Con-
  centrations - Galveston Bay -
  March 10, 1970

Water and Oyster Sampling Loca-
  tions -- FWQA Reconnaissance
  Survey,  November 1970
       Page


Follows Page 16


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Follows Page 46
                              111

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                       LIST OF FIGURES (CONT'D)
Figure No.
  VI-1
  VI-2
  VI-3
  VI-4
  VII-1
  VIII-1
              Title
Permitted Wastewater Discharges
  in the Calves ton Bay Area

Permitted Suspended Solids Dis-
  charges in Calves ton Bay Area

Permitted BOD Waste Discharges *
  in the Calves ton Bay Area

Permitted COD Waste Discharges
  in the Calves ton Bay Area

Classifications of Shellfish
  Harvesting Areas

Future Development
      Page


Follows Page 64


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Follows Page 80


Follows Page 90
                                  IV

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                        LIST OF TABLES
Table No.                    Title
 IV-1          Municipal and Industrial  Uses  of Water
                 in the Vicinity  of  Galveston Bay  1960,
                 and Projected 1990  and  2020                    22

 IV-2          Oyster Harvest and Value,  Galveston Bay          26

  V-l          Summary of Texas Water  Quality Standards
                 Applicable to Galveston Bay  and
                 Houston Ship Channel                           30

  V-2          Median Values of Total  Coliform Concen-
                 trations and Percentage of Samples
                 Greater Than 230 Coliform/100 ml  at
                 Selected Stations in  Galveston Bay
                 for Periods Dec.1968-April 1969 and
                 Dec01969-April 1970                           32

  V-3          Median Fecal Coliform Concentrations and
                 Percentage of Samples with Fecal  Coli-
                 form Concentrations Greater  than  33/100 ml
                 at Selected Stations  in Galveston Bay for
                 the Periods Dec.1968-April 1969 and
                 Dec01969-April 1970                           34

  V-4          Concentrations of  Heavy Metals Galveston
                 Bay - Houston Ship  Channel                     38

  V-5          Metals Concentrations in  Oysters from
                 Galveston Bay November  12, 1970                41

  V-6          Evaluation of Galveston Bay Oyster  Meats
                 for Odor                                      45

  V-7          Comparison of BOD  Standards with Observed
                 and Average Values                             49

 VI-l-A        Municipal and Domestic  Waste Discharges to
                 the Houston Ship Channel above Morgan
                 Point,  Including Baytown Area                  52

 VI-l-B        Municipal and Domestic  Waste Discharges to
                 Galveston Bay                                 56
                              v

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                    LIST OF TABLES  (CONT'D.)
Table No.                    Title                             Page
 VI-2-A        Waste Discharges from Petroleum,  Chemical,
                 Plastics,  and Rubber Industries to the
                 Houston Ship Channel or Its  Tributaries
                 Above Morgan Point Including the Baytown
                 Area                                           58

 VI-2-B        Other Industrial Discharges to the Houston
                 Ship Channel or Its Tributaries               60

 VI-2-C        Waste Discharges from Petroleum,  Chemical,
                 Plastics,  and Rubber Industries to
                 Galveston Bay or Its Tributaries               62

 VI-2-0        Other Industrial Discharges to Galveston
                 Bay or Its Tributaries                         63

 VI-3          Pollutants Associated with  Various Petro-
                 chemical Processes                             72

 VI-4          Discharges of Heavy Metals to  the Houston
                 Ship Channel                                   74

 VI-5          Summary of Permitted Waste Discharges,
                 Galveston Bay Area                             76
                              VI

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                           I.  INTRODUCTION





     Water quality standards were adopted for Galveston Bay and




its tributaries by the Texas Water Quality Board in June 1967 and




accepted by the Secretary of the Interior on January 28, 1968 in




accordance with the Federal Water Quality Act of 1965.  Pollution




of these waters is subject to the provisions of Section 10, Federal




Water Pollution Control Act, as amended (33 U.S.C. 466 et seq.).




Section 10(a) of the Act provides that the pollution of navigable




waters in or adjacent to any State, which endangers the health




or welfare of any persons, shall be subject to abatement.




     Section 10(d) of the Act further provides that a Federal-




State conference shall be called whenever, on the basis of reports,




surveys, or studies, there is reason to believe that substantial




economic injury results from the inability to market shellfish




or shellfish products in interstate commerce because of pollution




of such waters, and because of action of Federal, State or local




authorities.




     This report summarizes presently available information per-




taining to the quality of the Galveston Bay system; evaluates that




information with respect to applicable standards, statutes, regula-




tions, and criteria; and recommends a program which will lead to




compliance with established water quality uses.




     Specific objectives of the report are:




     (1)  To describe existing water quality in the Galveston Bay




system.

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     (2)  To summarize presently available information pertaining




to sources of pollution.




     (3)  To evaluate the impact of present waste discharges on




water quality and uses, and to assess compliance with established




State and Federal regulations.




     (4)  To indicate the effect of projected water related devel-




opment upon water quality in the Galveston Bay system.




     Sources of information contained in this report include:  the




National Estuarine Pollution Study, FWQA; the Texas Water Quality




Board; the Texas Parks and Wildlife Department; the Texas State




Department of Health; the Texas Water Development Board; the




Galveston Bay Study  (a cooperative Federal-State-local study




currently in progress), Texas A&M University and the U.S. Army




Corps of Engineers.  Limited field studies were also conducted by




the Division of Field Investigations, Denver Center, WQO - EPA,




to obtain additional data.  The cooperation and contribution of




the various State, local and private organizations are gratefully




appreciated.

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                     II.  SUMMARY AND CONCLUSIONS






     .The area considered in this report includes all of Galveston




Bay, Texas, and its major tributary streams and embayments.




     Nearly half of Galveston Bay is presently closed for shellfish




harvesting due to excessive bacteriological contamination and




the proximity to sewage and industrial waste effluents.  Total




coliform concentrations at two locations in the approved area of




Galveston Bay and one location in the approved area of West Bay




exceed the applicable criteria of 230 organisms per 100 milliliters




more than 10 percent of the time (Appendix B), based on monthly




samples collected by the Galveston Bay Study during the 1968-69




and 1969-70 shellfish harvesting seasons.




     Under the applicable standards for shellfish harvesting,




sampling to determine approved and prohibited areas must be con-




ducted under the most unfavorable hydrographic and pollution




conditions.  In Galveston Bay, the most unfavorable hydrographic




and pollution conditions occur with northerly and northwesterly




winds as well as precipitation.  During the 1968-69 shellfish




harvesting season, these conditions occurred about 40 percent




of the time.  On days when the most unfavorable hydrographic




and pollution conditions occur, virtually the entire approved




area in Galveston Bay, including the most productive reefs, have




total coliform concentrations exceeding the required criteria.  If




sampling were regularly conducted under these conditions, nearly

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all of Galveston Bay would be closed to shellfish harvesting due




to excessive bacteriological pollution.




     The major source of bacteriological pollution to both open and




closed areas for shellfish harvesting in Galveston Bay is the




Houston Ship Channel.  The Clear Lake area also contributed to




excessive total coliform concentrations in the Bay.  The City of




Galveston area, while not affecting concentrations in approved




areas, does discharge significant bacteriological pollution to the




closed areas.  There are localized influences of bacteriological




pollution in West Bay approved areas from Chocolate Bayou and in




Galveston Bay proper from Double Bayou.




     Of the more than 215 million gallons per day  (MGD) of domestic




waste which are permitted by the Texas Water Quality Board to be dis-




charged to Galveston Bay and its tributaries, about 110 MGD is raw,




inadequately treated and/or unchlorinated.  As of January 1971, the




two largest sewage treatment plants of the City of Houston which dis-




charge to the Ship Channel area, the Northside and Sims Bayou plants,




account for 103 MGD of unchlorinated discharge.  The effluent from




each of these plants contained nearly 35,000,000 total coliform




organisms per 100 milliliters during February 1969 sampling.




     Oil and hydrocarbon residues were observed in oysters taken




from both approved and prohibited areas of Galveston Bay, ranging




from 23 parts per million  (ppm) and 26 ppm in the approved area to




237 ppm in a prohibited area near the mouth of the Houston Ship

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Channel.  These hydrocarbons are not generated by the oysters




themselves but derived from petroleum wastes.  The concentrations




observed in oysters taken from approved areas in Calveston Bay are




from two to six times greater than concentrations in oysters from




West Falmouth Bay, Massachusetts.  The State of Massachusetts




closed West Falmouth Harbor to shellfish harvesting, based on




residues in oyster tissue ranging between 4.0 ppm and 12.0 ppm.




Odor tests on Galveston Bay oysters showed unacceptable concentra-




tions of odor-causing materials in all samples from both approved




and prohibited harvesting areas.  The intensity of odor became less




as distance from the Houston Ship Channel increased.  There is a




health hazard, in addition to bacteriological pollution, associated




with consumption of Galveston Bay oysters due to the presence of




oil and hydrocarbon residues in excessive concentrations.




     According to 1968 Texas Water Quality Board permits, there




are 75 sources of petroleum refining or related industrial effluents




in the Galveston Bay area.  These effluents constitute a permitted




discharge of nearly 423 MGD with a total of 1,144,000 pounds per day




of chemical oxygen demand.  The permits allow the discharge of




more than 55,000 pounds per day of oil and grease from 81 sources,




although this is in direct violation of Section 11-b of the Federal




Water Pollution Control Act as amended.  The Texas Water Quality




Requirements specify that receiving waters shall be "substantially




free" of oil.  Seventy-four of these sources are located on the




Houston Ship Channel, accounting for 98 percent of the total

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permitted discharge.  The major industries permitted to discharge




oil and grease are:  Diamond Shamrock Corporation at Deer Park,




U. S. Plywood-Champion Paper Company, Armco Steel Company, Atlantic




Richfield Company, humble Oil and Refining Company, Southland Paper




Mills, Shell Chemical Company, and Crown Central Petroleum Company.




These eight sources account for 86 percent of the permitted dis-




charges .




     It is estimated that 1,600 pounds per day of lead, 5,000




pounds per day of cadnium, 400 pounds per day of phenols, 7,900




pounds per day of zinc, 300 pounds per day of chromium and at




least 1,000 pounds per day of cyanide are discharged, primarily to




the Houston Ship Channel.  Concentrations of these heavy metals




and toxic compounds in the waters of Galveston Bay and the Houston




Ship Channel range from 8.5 times greater than background in




natural seawater for nickel, to 108,000 times greater than




background for chromium.  These concentrations indicate substantial




contamination of the receiving waters by waste discharges.  Con-




centrations of toxic compounds in the Houston Ship Channel are three




times greater than levels which could be tolerated for normal algal




growth.  The known major dischargers of heavy metals contamination




are Diamond Shamrock Company, Armco Steel Company, Olin llathieson




Corporation, Houston Northside sewage treatment plant, U. S. Plywood-




Champion Paper Company, Humble Oil and Refining Company  (Baytown),




and Shell Chemical Company  (Deer Park).  These sources discharge more than

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500 pounds per day as determined by sampling conducted by the




Texas Water Quality Board in February 1969.  Although the health




hazard and specific numerical criteria associated with concentrations




of heavy metals and toxic substances has not been established by the




appropriate regulatory agencies, the Texas Water Quality Requirements




prohibit acute or chronic toxicity to human, animal, or aquatic life.




     Dissolved oxygen and biochemical oxygen demand (BOD) criteria




established by the State of Texas for the Houston Ship Channel




are almost continually violated due to the discharge of municipal




and industrial wastes.  Although the Texas Water Quality Board




permits specify that 180,800 pounds per day of BOD may be discharged




from municipal and industrial sources to the Houston Ship Channel,




studies conducted in the Channel during 1968 and 1969 indicate




that as much as 363,000 pounds per day of five-day BOD is the actual




loading.  The aggregate total of waste discharges to the Ship




Channel is in substantial non-compliance with the Texas Water




Quality Board permits.




     The 1968 permits allow the discharge of 315,000 pounds per day




of suspended solids to the Houston Ship Channel.  Bottom material




dredged from the Ship Channel contains substantial quantities of




organic sludges, oil and other pollutants characteristic of wastes




discharged to the Channel.  About one-third of the BOD loading and




one-half of the suspended solids discharged from waste sources




settle out and are incorporated in the bottom sediments.  These

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waste materials contribute a substantial portion of the sediments




which must periodically be removed by dredging.  The total project




cost incurred by the U.S. Army Corps of Engineers for dredging the




Houston Ship Channel in 1970 is $2,807,000.  The disposal of this




highly organic spoil may cause water quality problems through disper-




sion of pollutants and through exercise of oxygen demand from the




volatile material contained.




     The total permitted discharge of waste effluent to Galveston




Bay and its tributaries is approximately 779 MGD which may contain




583,000 pounds per day of suspended solids, 270,000 pounds per day




of BOD and 1,657,000 pounds per day of chemical oxygen demand (COD).




Of this total, 92.6 percent of the suspended solids, 85.5 percent




of the BOD and 92.8 percent of the COD are allocated to industrial




sources.  Industrial sources contribute about 72 percent of the




total waste flow.




     Of the 277 municipal and industrial waste sources having




discharge permits in the Galveston Bay area, the waste treatment



needs and status of 189 are not listed.  Where needs are indicated,




40 sources provide inadequate or no treatment and no abatement,




beyond engineering studies in a few instances, is in progress.




Seventeen sources have treatment facilities in progress; 22 are




said to be in compliance with permit requirements.  Nine sources




either provide adequate treatment or have no needs.




     The City of Houston discharges wastes from 41 treatment plants,




only eight of which have flows greater than 1 MGD.  Harris County

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sewer districts discharge wastes from 27 sources, only one of




which has a flow of 1 MGD.  Galveston has three sources and




Baytown has five.  The multiplicity of waste treatment plants does




not provide adequate operations to assure the best treatment of




domestic sewage.




     The development of an electrical power plant at Cedar Bayou




by the Houston Lighting and Power Company will eventually require




about 5,000 cubic feet per second (cfs) of cooling water.  Some




of the intake cooling water will consist of grossly polluted




water from the lower reaches of the Houston Ship Channel.  The




heated water will be discharged to the relatively unpolluted




Trinity Bay.  Water temperature in a large portion of Trinity




Bay will be raised above background.  Trinity Bay is the major




spawning area for commerical shrimp in Galveston Bay.




     The present actual economic loss to the Galveston Bay area




caused by inability to market shellfish due to pollution ranges




between $86,000 and.$258,000 annually at dockside.  If excessive




hydrocarbon or heavy metals concentrations in oysters and/or




sampling under the most unfavorable hydrographic and pollution




conditions, as required, caused the closure of all Galveston Bay




to shellfish harvesting, the potential damage would be substan-




tially greater.  The final retail value of shellfish products is




roughly four times the dockside value.  The total actual damages




caused by pollution affecting shellfish harvesting in Galveston Bay




are between $359,000 and $1,045,000 annually.

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           Sewage and industrial wastes discharged to Galveston Bay and




      its tributaries are causing substantial economic injury resulting




      from the inability to market shellfish or shellfish products in




      interstate commerce.  Accordingly, the pollution of these navigable




      waters is subject to abatement under the provisions of Section 10




      of the Federal Water Pollution Control Act, as amended (33 U.S.C.




      1151 et seq.).

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                        III.  RECOMMENDATION S







     To eliminate the health hazard associated with consumption




of shellfish from the Galveston Bay system and to abate the




existing pollution, it is recommended that:




     1)  Due to concentrations of oil and hydrocarbon residues in




oysters taken from approved areas in Galveston Bay, the Texas  State




Department of Health, in cooperation with the Food and Drug Administration,




ascertain the extent of health hazard  incurred,  and, if warranted,




recommend closure of Galveston Bay to shellfish harvesting.  Consideration




be given to prohibition of all commercial fishing in Galveston Bay until




it has been ascertained that the marine species taken from the Bay are




suitable for human consumption




     2)  Sampling for determining bacteriological acceptability of




areas for shellfish harvesting in Galveston Bay be conducted under




the most unfavorable hydrographic and pollution conditions as  required




by applicable regulations.  The most unfavorable hydrographic  and




pollution conditions occur with northerly and/or northwesterly winds




during or following periods of precipitation.




     3)  Effective disinfection of all waste sources contributing




bacteriological pollution to Galveston Bay be provided.   A program of




centralization and abandonment of small plants be undertaken to assure




the best treatment for domestic sewage,  with an implementation schedule




to be submitted to the Conferees within three months ofvthe date of the




first session of the Galveston Bay Enforcement Conference.

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           4)  A waste source survey be conducted on all sources of




      domestic and industrial waste permitted by the Texas Water Quality




      Board to discharge effluent to Galveston Bay and its tributaries.




      This survey should characterize and quantify specific compounds




      being discharged and include recommendations and scheduling of




      abatement measures.  A characterization and scheduling of abatement




      for the 55 waste sources discharging more than 500,000 gallons per




      day be submitted to the Conferees within eight months of the date




      of the first session of the Galveston Bay Enforcement Conference.




      The Texas Water Quality Board permits be amended to reflect the




      recommendations of this waste source survey including the compliance




      schedule.




           5)  The Texas Water Quality Board permits be amended to




      immediately prohibit the discharge of oil and grease as well as




      toxic materials from all waste sources.




           6)  The additional costs incurred by the Corps of Engineers




      for dredging of the Houston Ship Channel and the effect on water




      quality due to disposal of the organic sludge be evaluated.  Rec-




      ommendations of this evaluation include an assessment of damages




      among the waste dischargers to the Channel and, location of suit-




      able spoil disposal areas to minimize or eliminate deleterious




      effects on water quality.




           7)  The Houston Lighting and Power Company be required to




      abate the waste heat load to be discharged from the Cedar Bayou

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                                                                      13
plant to Trinity Bay such that the monthly mean of the maximum




daily temperatures not be raised more than 4 F during the fall,




winter and spring (September through May), or by more than 1.5 F




during the summer (June through August) at the point of discharge.




A cooling system incorporating recirculation and reuse be installed




at the Cedar Bayou power plant.  The Houston Lighting and Power




Company also insure that no deleterious effects or impairment of




water quality occur in Trinity Bay by reason of the use of a polluted




source for cooling water.




     8)  A committee be appointed to make recommendations to the




Secretary of Health, Education, and Welfare and the Administrator




of the Environmental Protection Agency within one year from the




date of establishment, on interim specific numerical criteria in




both water and meat for acceptance of shellfish and other commer-




cially valuable species taken from Galveston Bay.  The specific




numerical criteria to include bacteriological, oil and hydrocarbon




residue, taste and odor, as well as other acute and chronically




toxic or growth-inhibiting parameters.  The committee include




representatives of the Food and Drug Administration and the




Environmental Protection Agency, in cooperation with appropriate




Texas regulatory agencies.




     9)  Color of the waste effluent from U.S. Plywood-Champion




Paper Company and Southland Paper Mills be reduced to natural




background occurring in uncontaminated area waters.

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           10)  An assessment be made of the total waste load which can




      be discharged to Galveston Bay and/or its tributaries to meet




      applicable State and Federal water quality standards as well as




      the recommendations of this report.  This waste load be allocated




      among individual waste dischargers and not be exceeded regard-




      less of future development.

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                                                                      15
                       IV.  DESCRIPTION OF AREA






A.  PHYSICAL DESCRIPTION




     Galveston Bay is located in southeastern Texas on the Gulf of




Mexico about 25 miles southeast of Houston, the largest city in




the State.  The Galveston Bay estuarine system, consisting of four




large bays, Galveston, Trinity, East, and West Bays, and numerous




smaller bays, creeks and bayous, has a total surface area of




about 533 square miles and is the largest estuary on the Texas




coast.  The combined shoreline totals 245 miles.




     The major bays are broad and shallow, averaging less than ten




feet in depth.  The smaller bays, creeks and bayous are shallow and




sluggish.  Marshes border the open water in many areas.




     Most of the land surface adjacent to the bay system is only a




few feet above sea level and is virtually flat for about 50 miles




inland from the Gulf of Mexico.  The natural drainage is poorly




defined and has been altered by irrigation, drainage canals, and




other man-made waterways.




     Impoundments on the Trinity and San Jacinto Rivers regulate




fresh water inflows from these streams.  As a result, the hydrology




of the estuary is influenced primarily by inflows from an area of




3,600 square miles in the immediate vicinity.  The area includes




600 square miles of the lower Trinity River Basin, 1,500 square




miles of the lower San Jacinto River Basin, and 1,500 square miles




which drain directly into the bay system through bayous and

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      creeks.  The total drainage area of Galveston Bay is 24,300 square




      miles of which 17,800 square miles is in the Trinity River system




      and 3,900 square miles in the San Jacinto system.  The remaining




      2,500 square miles is from numerous small streams draining to




      the bay.




           Three major passages connect the estuary with the Gulf of




      Mexico.  San Luis Pass and Rollover Pass, an artificial fish




      passage, are outlets for West and East Bays, respectively.  The




      largest passage is Bolivar Roads, located between Galveston Island




      and Bolivar Peninsula.  This openeing is the primary outlet for




      the estuarine system.




           Several navigation channels are located in the estuary.  Of




      major importance is the Houston Ship Channel, a dredged deep-draft




      channel which enters Bolivar Roads, traverses Galveston Bay, the




      San Jacinto River and Buffalo Bayou, and terminates in Houston




      about 50 miles from the Gulf of Mexico.  Shorter deep-draft




      channels connect port facilities in Galveston and Texas City




      with the shallow-draft Intracoastal Waterway which traverses




      East and West Bays.  Other shallow waterways connect various




      points in the estuary system.  The area under consideration is




      illustrated in Figure IV-1.






      B.  CLIMATE




           The average annual rainfall in the Houston area is approxi-




      mately 45 inches per year, with monthly rainfall evenly distributed

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                                               o
Figure IV-1
Calves ton Bay Area

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                                                                      17
throughout the year.  Thunderstorms are the main source of precipi-




tation, with rainfall of several inches per day not uncommon.




     Temperatures are moderated by the influence of winds from the




Gulf, which result in mild winters and warm humid summers.  Average




daily temperatures range from about 53 F in the winter to about 83 F




in the summer, with an annual mean temperature of 69 F.




     Prevailing winds are from the southeast and south, except in




January, when frequent passages of high pressure areas bring




prevailing northerly winds.  Thundersqualls and tropical storms




with high wind velocities occasionally pass through the area.






C.  HYDROLOGY




     Freshwater inflow to the estuarine system from the Trinity




and San Jacinto Rivers and other coastal streams averages about




11,300 cubic feet per second (cfs), or an average annual volume of




8.2 million acre-feet.  Both the rate of inflow and the annual




runoff fluctuate widely.  For example, in 1965 the average weekly




inflow varied from less than 1,000 cfs to more than 45,000 cfs.




Between 1941 and 1957, total annual inflow varied from less than




2 million acre-feet to more than 20 million acre-feet.  Precipita-




tion falling directly on the water surface of the estuary contributes




a fresh water inflow of about 1.4 million acre-feet annually.




     The location, relative magnitude and variability of the major




sources of freshwater exert a strong influence on water quality in




the estuarine system.  The Trinity and San Jacinto Rivers together

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      contribute almost 90 percent of total freshwater inflow.  With an




      average annual flow rate of 7,900 cubic feet per second, the Trinity




      River strongly influences salinity levels in Trinity Bay.  The




      Houston Ship Channel traverses the lower ten miles of the San




      Jacinto River.  High flows in the river thus tend to flush degraded




      water from the middle reach of the ship channel out into Galveston




      Bay.  Buffalo Bayou, a small stream with a drainage area of about




      360 square miles, discharges into the upper end of the ship channel




      in the City of Houston.  Peak flows in the bayou following heavy




      rainfall frequently flush the water contained in the upper 25




      miles of the ship channel, into Galveston Bay.




           A major portion of the water supply for municipal and industrial




      purposes in the Galveston Bay area is obtained from groundwater




      sources.  The principal freshwater aquifer in the area is the




      Gulf Coast Aquifer which has a saturated depth exceeding 3,000 feet.




      Recharge of the aquifer is adequate to sustain the present rate of




      pumping if the withdrawal points were adequately dispersed.  Sus-




      tained heavy withdrawals in local areas have caused overdrafts




      of the aquifer.  Declining water tables, land subsidence and




      salinity intrusion problems have resulted.  A reduction in ground




      water withdrawals is expected in the future as these problems




      become more severe and alternate surface supplies become available.




           Two types of tides occur in the Galveston Bay estuary during




      normal weather.  Diurnal tides, with an average range of 1.25 feet,




      exist during  two to three weeks per month, and semi-diurnal tides,

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                                                                      19
with an average range of 0.5 feet, prevail during the remaining

period.  The complex geometry of the bay causes amplifications and

reflections of normal tidal effects resulting in considerable

spatial variation in tides.  During unusual weather conditions,

such as high winds or the passage of a cold front, the Galveston

Bay tides become wind-dominated and no consistent tidal performance

can be observed.

     Current measurements made by the Corps of Engineers show that

ebb and flood currents in the Houston Ship Channel are about 1.5

feet per second— .  In shallow areas of Galveston Bay, water currents

average between 0.3 and 0.4 feet per second.  However, in some of

the passes and channels between reefs, currents may range as high

as four feet per second.


D.  POPULATION

     The population of the Galveston Bay Basin, including three

counties and portions of four additional counties, was estimated at

1.4 million in 1960.  By 1968, the population had increased to an

estimated 1.8 million.  The Houston Standard Metropolitan Statistical

Area (SMSA), with 1970 population of 1.9 million, and the Galveston-

Texas City SMSA, with combined 1970 population of 178,000, are the

most important urban areas.
I/  Bobb, W. H., and R. A. Boland, Jr., Galveston Bay Hurricane Surge
      Study, Technical Report H-69-12, July 1970, U.S. Army Engineer
      Waterways Experiment Station, Vicksburg, Mississippi.

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20
           The population of the area is expected to continue the rapid




      growth rate of recent years.  Projections indicate that the popula-




      tion of the area will triple by the year 2020.






      E.  ECONOMY




           The economy of the area rests heavily on manufacturing, chiefly




      in the petrochemical field.  Manufacturing is concentrated around




      the southern and western shores of Galveston Bay, in the Houston




      metropolitan area, and along the Houston Ship Channel.  This concen-




      tration is expected to become more pronounced as the potential




      development of the area is realized.




           Since construction of the Houston Ship Channel in 1914, Houston




      has become a major port, now surpassed in total tonnages handled by




      only two other U.S. ports, New York and New Orleans.  The require-




      ment for sites located near the Texas oil fields and major shipping




      lanes has led to intensive development along the Ship Channel of




      refineries, chemical and petrochemical manufacturing plants.




      Fertilizer factories, gypsum and cement plants, two steel mills,




      paper manufacturing and other industrial facilities are also located




      adjacent or in close proximity to the Ship Channel.




           Location of the National Aeronautics and Space Administration's




      Manned Spacecraft Center near Clear Lake on Galveston Bay has




      attracted associated components of the aerospace industry to the




      Houston metropolitans-area and has helped to diversify the economy.




           The service industries^tnd local, State, and Federal govern-




      ment are presently the largest employers in the area.  This category

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                                                                      21
of employment along with employment by the trade industries is




projected to substantially increase in the future relative to




employment in manufacturing and other categories.






F.  WATER USE




     A variety of beneficial uses is made of the waters of the




Galveston Bay estuarine system and tributary streams.  The most




important of these uses include municipal and industrial water




supply, propagation of fish and wildlife, navigation, recreation,




and irrigation.  The rapidly expanding electrical power requirements




for the Galveston Bay area are being paralleled by increased use of




water for cooling purposes.






Municipal and Industrial Water Supply




     Water use for municipal and industrial purposes other than




condenser cooling water was estimated in 1960 to total about 608,000




acre-feet per year (544 million gallons per day-MGD) for the




Galveston Bay area.  Almost 80 percent of this water supply was




obtained from groundwater, as shown in Table IV-1.  The relative




use of water at various locations in the area is also shown in the




table.  It is estimated that average annual water use will total




about 1.7 million acre-feet (1,520 MGD) by 1990 and 3.3 million




acre-feet (2,850 MGD) by 2020.




     In 1968, nine public utility steam electric generating plants




were operating in the vicinity of Galveston Bay.  These plants




have a production capacity of 3,632 megawatts and a peak demand

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22

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