Browsing by Author "Crocker, Philip A."
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Item Contaminant Assessment of Patrick Bayou(Texas Natural Resource Conservation Commission Field Operations Division, 1996-12) Broach, Linda; Crocker, Philip A.In July 1994, the Texas Natural Resource Conservation Commission (TNRCC) and United States Environmental Protection Agency (EPA) Region 6 conducted an ambient toxicity and water and sediment quality survey of Patrick Bayou, a small tributary of Segment 1006 of the Houston Ship Channel (HSC). Patrick Bayou is bounded by and receives effluent from several industrial dischargers and one municipal wastewater treatment plant. This area was investigated because a recent HSC study found ambient water and sediment toxicity and elevated levels of several priority pollutants in Patrick Bayou. The primary objective of this study was to collect water and sediment samples in Patrick Bayou to provide information on the magnitude and spatial distribution of contamination and toxicity in this small bayou. Ten stations were chosen for priority pollutant analyses and a TNRCC routine monitoring station was also sampled during the survey. Several stations were selected for water and/or sediment toxicity testing. Out of five stations tested, water from four was toxic to Mysidopsis bahia and one of those was also toxic to Menidia beryllina. Significant mortality to Cyprinodon variegatus was observed in two of five sediment elutriate tests. State water quality standards were exceeded in Patrick Bayou for dissolved copper (8 sites), dissolved lead (3 sites), total mercury (1 sites), carbon tetrachloride (1 site), and water temperature (4 sites), although a few of these exceedances were inside mixing zones. Three Patrick Bayou stations has unionized ammonia values that exceeded the EPA chronic criteria for saltwater. More than 40 percent of the sediment samples in Patrick Bayou exceeded TNRCC sediment screening levels (85th percentiles) for Cr, Cu, Pb, Hg, Ni, Se, Zn, hexachlorobenzene, total polychlorinated biphenyls (PCBs), and bis(2-ethylhexyl) phthlate. Very high levels of mercury (8.3 ppm), hexachlorobenzene (83,900 ppb), hexachlorobutadiene (138,000 ppb), PCBs (4,150 ppb), polynuclear aromatic hydrocarbons (total PAHs 233,700 ppb), and lead (269 ppb) were found in Patrick Bayou sediments. State screening levels were not available for the remaining 24 organic compounds found in the sediments. Lead, mercury, PCBs, acenapthene, acenaphthylene, anthracene, fluorene, naphthalene, 2-methylnaphthalene, phenanthrene, benzo(a)anthracene, benzo(a)pyrene, chrysene, fluoranthene, pyrene, and total PAHs all exceeded the effects range median levels developed by the National Oceanic and Atmospheric Administration. Overall, Patrick Bayou showed a significant accumulation of many priority pollutants in sediments, exceedances of several water quality standards, and ambient toxicity in both water and sediment. The specific distribution of the contaminants in the sediments gave some information on their potential sources. The major dischargers along Patrick Bayou have proposed to sample their effluents for the compounds found in the bayou to further pinpoint the sources.Item Preliminary Assessment of Nonpoint Source Related Ambient Toxicity in and around Lower Galveston Bay(Ecosystems Protection Branch, US Environmental Protection Agency, Region 6, August 1995) Crocker, Philip A.; Broach, Linda; Hollister, Terry A.; Stockton, David C.; Lane, WillieIn 1991 aquaculture researchers at the old SeaArama facility in Galveston believed that mortality they were observing in their larval shrimp cultures was a result of toxicity of ambient water in the Gulf of Mexico. The researchers utilized near-shore Gulf of Mexico water for rearing larval shrimp. They hypothesized that 2-butoxyethanol was the toxic agent, originating from Galveston Bay waters flowing into the Gulf following heavy rainfall. However, data were not available to support this hypothesis. The US Environmental Protection Agency (EPA) and the Texas Natural Resource Conservation Commission (TNRCC) in a combined effort decided to conduct a water quality study to investigate these concerns. The purposes of the study were to assess the potential for ambient toxicity in lower Galveston Bay and the Gulf of Mexico following rainfall events, and to determine the need for additional studies for a more complete assessment. A total of five stations were sampled during three sampling events: (I) November 1992, (II) June 1993 and (III) February 1994. Sampling stations included Galveston Bay near Redfish Reef, Galveston Channel, and near-shore Gulf of Mexico off Galveston Island. Two additional industrialized areas were also sampled, Texas City Ship Channel and Chocolate Bay. An attempt was made to sample following significant rainfall in the Galveston Bay watershed to assess the potential impact of nonpoint source pollution on bay water quality. Ambient surface water samples were collected for chemical analysis of conventional parameters, EPA priroity pollutants (heavy metals, VOCs, semi-volatiles, pesticides and PCBS), and chronic toxicity testing with mysids and inland silversides. Overall, chemical water quality was good for all sites. The chemical analysis yielded no violations of state water quality standards. Bis(2-ethylhexyl)phthalate at the Gulf of Mexico station exceeded the EPA criterion for protection of human health in February 1994, although the significance is doubtful as this is a common lab contaminant. In November 1992 dissolved nickel approached the state's chronic water quality standard at Chocolate Bay. Chronic toxicity data for mysids and inland silversides, although limited, did not indicate signifcant chronic effects to either species. Because this was a screening study data should be considered preliminary. Chemical and toxicity data indicate that aquatic life uses in the open bay areas sampled are not impacted by toxic substances originating from non-point sources. The need for future open bay type nonpoint source surface water studies is considered low. Studies to assess localized and/or episodic effects of urban stormwater discharges and industrial and agricultural runoff (e.g., western near-shore areas of Galveston Bay; Chocolate Bayou upstream of the area sampled in this study) would be of greater value.Item Sediment Quality Guidelines for Galveston Bay and Other Texas Estuaries(Texas Natural Resource Conservation Commission, 2001) Crocker, Philip A.; Proceedings: The State of the Bay Symposium V. January 31 - February 2, 2001Bottom sediment serves a sink, as a result of deposition, and as a source of pollutants to the water column and organisms. Sediment is an integral component of aquatic ecosystems, providing habitat, feeding, spawning and rearing areas for many aquatic organisms. Benthic organisms are in direct contact with bottom sediments and pore waters. Bottom sediment quality is assessed under the Texas Natural Resource Conservation Commission (TNRCC) Surface Water Quality Monitoring (SWQM) Program, as well as through various other agencies and programs. Sediment quality is a key environmental indicator of status and trends for estuaries. In order to interpret the degree of contamination, and the need for management, it is important to utilize available assessment tools such as sediment quality guidelines.; The purpose of utilizing sediment quality guidelines in assessing the bottom sediments is to estimate the effects of toxic pollutants on benthic communities. Water quality criteria or standards, which are designed to protect aquatic organisms residing within the water column, may not be protective of benthic organisms. For this reason it is appropriate to integrate sediment quality guidelines, along with benthic community assessment and toxicity testing to evaluate impacts to these communities. This paper presents guidelines for selected pollutants applicable to Galveston Bay and other Texas estuaries, and provides recommendations on assessing the degree of contamination.Item Trends in Selected Water Quality Parameters for the Houston Ship Channel(United States Environmental Protection Agency, 1992-09) Evans, Diane; Schrodt, Barbara J.; Koska, Paul C.; Crocker, Philip A.While many believe water quality in the Houston Ship Channel is improving, water quality trends have not been adequately verified and documented. An investigation was made utilizing ambient monitoring data to make inferences on water quality trends for selected parameters. Twenty-one water quality parameters were assessed including conventional parameters (DO, TSS, fecal coliforms, BOD and TOC), nutrients (ammonia, nitrate, nitrite, Kjeldhal nitrogen, orthophospate and total phosphate), and heavy metals (arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver and zinc). In addition, heavy metals and PCBs in sediment are mentioned, although data are more limited for these parameters. Concentrations over the last 10-20 years were plotted, and assessed over time using statistical correlation (Pearson, Spearman and Kendall tau-b correlations). The primary database used was the Texas Water Commission state monitoring network (SMN) data. The five Ship Channel stations assessed are located at Morgans Point at the mouth, proceeding upstream to Channel Marker 120, San Jacinto Monument, at the Greens Bayou confluence, and the turning basin (the upstream extent of the Ship Channel).Item Trends in Selected Water Quality Parameters for the Houston Ship Channel - April 1992 Draft(United States Environmental Protection Agency, 1992-04) Crocker, Philip A.This is the draft edition of the item found at Accession # 10393.Item Trends in water and sediment quality for the Houston Ship Channel(November 1996) Crocker, Philip A.; Koska, Paul C.; Texas Journal of ScienceAmbient monitoring data collected by the Texas Natural Resource Conservation Commission from 1971 through 1991 were assessed for five stations located on the Houston Ship Channel mainstem (Turning Basin, Greens Bayou, San Jacinto Monument, Channel Marker 120 and Morgans Point). Water quality was most impacted in the upper channel, especially at the Turning Basin, improving downstream of the San Jacinto River confluence. This is consistent with the more confined physical characteristics and the high degree of point and non-point source pollutant loading in the upper channel. Water quality has improved over the last couple of decades as demonstrated by declining trends for total organic carbon, total suspended solids, fecal coliforms, ammonia nitrogen, orthophosphate, total phosphate, total arsenic and total copper. Increases in nitrate nitrogen, over time were found at all sites. Declining trends for total cadmium, mercury, nickel and zinc were found for the upper (industrialized) portion of the channel only. Other findings for total metals indicated site-specific differences for silver, possible increasing trends for selenium and no trends for chromium. Increasing dissolved oxygen and decreasing biochemical oxygen demand and Kjeldahl nitrogen concentrations were evident at the upstream stations but, unexpectedly, trends reversed further downstream. Concentrations of heavy metals and PCBs in bottom sediment were greatest in the Turning Basin and dropped progressively downstream. Levels of arsenic, cadmium, lead and zinc in Turning Basin sediments decreased significantly over time. Improving water and sediment quality has enhanced utilization of the Ship Channel system by aquatic life.Item Water quality and ambient toxicity investigation of the Houston Ship Channel and Tidal San Jacinto River(Galveston Bay National Estuary Program, 1991) Crocker, Philip A.; Shipley, Frank S. and Russell W. Kiesling; Proceedings: Galveston Bay Characterization Workshop. February 21-23, 1991No abstract availableItem Water quality trends for the Houston Ship Channel(Galveston Bay National Estuary Program, 1993) Crocker, Philip A.; Jensen, Richard W. Russell W. Kiesling, and Frank S. Shipley; Proceedings: The Second State of the Bay Symposium. February 4 - 6, 1993While there have been indications that water quality in the Houston Ship Channel is improving, temporal trends have not been adequately verified and documented. An investigation was made utilizing ambient monitoring data to make inferences on water quality trends for selected parameters. The purpose of this paper is to present results of this investigation. The study findings are more thoroughly discussed by Crocker et al.(1992).