Note: This information is provided for reference purposes only. Although the information provided here was accurate and current when first created, it is now outdated.

Bld 20 - Marine Toxicology & Chemistry Lab

The Ecotoxicology & Chemistry Laboratory is a 12,500 ft² (10,000 ft² on ground level) facility that includes  5000 ft² of wet laboratory space 2500 ft² of analytical chemistry space 2500 ft² for storage and non-office work space 1250 ft² of office space and 1250 ft² for preparatory laboratories and a fully equipped workshop and glass shop. Marine Toxicology The wet laboratory includes 27 wet tables equipped to receive flow-through water and six holding tanks with recirculating filtration systems. Many of the wet tables can be used for toxicity testing or culture of organisms; those used in toxicity testing can be exhausted to the exterior of the building if desired. Seven tables are equipped with special dosing systems which deliver precise levels of exposure solutions during toxicity testing. The tables have curtains to help in maintaining desired photoperiods and to prevent unnecessary disturbance of animals. Each wet table is equipped to receive filtered seawater of ambient salinity, controlled salinity, or high salinity, or freshwater suitable for experimentation. Also, two tables receive unfiltered seawater pumped directly from Santa Rosa Sound for selected experiments such as those involving colonization parameters or oysters. The facility has a single-pass heating/air-conditioning system and is equipped with a diesel generator capable of maintaining the entire electrical load when the commercial supply of electricity is interrupted.  A grid, made of Unistrut®, is suspended at ceiling level above the wet lab tables for supporting experimental apparatuses, conduit, and water delivery pipes. Special features of the facility include the following:  Seawater Delivery System A 300 gallon per minute (gpm) continuous-flow automated water delivery system provides researchers with a choice of freshwater or filtered seawater of ambient salinity, controlled-salinity (20‰), or high salinity. Overall, the system consists of three 9,000 gallon and three 6,000 gallon elevated fiberglass water tanks, six high capacity water pumps, two blowers (provide aeration to tanks), 18 electronic water and air valves, two proportional water valves, seven water quality sensors, sand filters, charcoal filters, 20 µm cartridge filters, and extensive PVC pipe, fittings, and connectors. All of the electronic equipment and sensors are computer-controlled and continually monitored. Water quality parameters are logged every 15 minutes and can be retrieved as needed. The system operates in the following manner: Seawater is pumped directly from Santa Rosa Sound through sand and 20µm filter cartridges and is stored in one of the 9,000 gallon tanks. Freshwater (Pensacola City municipal drinking supply water) is processed through charcoal and 20µm filters and stored in a second 9,000 gallon tank with aeration. One of the 6,000 gallon tanks is used to store filtered high salinity (27‰ or above) seawater and is replenished whenever high salinity water is available in Santa Rosa Sound. The third 9,000 gallon tank is used to store salinity-controlled seawater (20‰), the standard seawater used for most of the experiments in the laboratory and commonly recommended for use by EPA guidelines. Salinity-controlled seawater is made by proportionally mixing filtered seawater with either freshwater or high salinity seawater to achieve 20±1‰. All water is gravity-fed into the laboratory and regulated by user controlled valves at each work station.   Temperature Control Water used in the wet laboratory is temperature controlled and usually maintained at 25 C by heaters and chillers. However, tests may be conducted at higher or lower temperatures, depending on the test parameters. Heaters are installed in troughs above each wet table (i.e., water bath) and in head boxes on pillars extending above the Unistrut® grid. Portable chillers are used as needed, especially during the summer months, to cool individual water baths and maintain specific test temperatures For quality assurance purposes, temperature is monitored in the wet laboratory experimental areas by an automated temperature logging system. Temperature probes available to each work station (wet table or tank) transmit their signals back to a pair of data loggers which serially transmit data to the Division's computer systems. Investigators can download and run statistical analyses on the logged data.   Effluent Treatment System Contaminated water discharges from the laboratory flow to a continually operating effluent treatment system. The treated water is monitored according to the operating permit requirements. After on-site treatment, the water is piped to a municipal sewage treatment facility.   Cultures Several different aquatic species are maintained in continuous cultures. Phytoplankton, rotifers, pelagic invertebrates, benthic invertebrates, molluscs, and fish are typical of those organisms available for use.   Outdoor Facilities In addition to the water delivery system, an outdoor aquarium cleaning station and fiberglass tanks receiving unfiltered flowing seawater are located outside the main laboratory. The holding tanks are used for maintaining cultures of organisms such as fish, submerged aquatic vegetation, or oysters. One tank contains a continually maintained oyster population used in monitoring the chemical quality of the natural seawater pumped from Santa Rosa Sound.   Environmental Chambers A temperature-controlled walk-in freezer and refrigerator are located adjacent to the main lab. These converted environmental chambers (buildings 59 and 60) are used for preserving environmental samples in preparation for analysis or for use in exposure experiments in the wet lab.   Dissolved Oxygen (DO) System A unique component of the wet laboratory is a computer-controlled dissolved oxygen (D.O.) exposure system used for controlling the D.O. content of test water. D.O. concentrations in flowing seawater are maintained according to the study design utilizing a vacuum degassing column and a gas saturation column; water from the two columns is combined proportionally to achieve the desired flow rate, temperature, and D.O. content. This system is used for examining D.O. requirements of saltwater animals and the information collected will be important in assessing the effects of eutrophication on saltwater animals.   Image Analysis System The image analysis system incorporates the use of high magnification light microscopy with the digitizing ability of specialized cameras and computer hardware and software to create graphical images capable of being easily quantified and digitally transferred. This advanced capability allows investigators to utilize computer power to capture and analyze multiple or complex images in the fraction of the time it would normally take. Images can be quantified in any way which relates to size, enumeration, and classifications based on these and other parameters. Also, microscopic images can be recorded from the digitized images or straight from the scope/camera, especially for living organisms, to the standard VCR. This is especially helpful for recording multiple images to be analyzed later or for recording images of living organisms that are required to remain under experimentation.   Chemistry Laboratory This 2500 sq. ft facility, completely renovated in 1998, consists of six separate areas; Liquid Chromatography, Gas Chromatogaphy, metals analyses, aqueous chemistry sample preparation, organic extractions sample preparation, and standards repository and preparation. The liquid Chromatography area consists of an Agilent 1100 HPLC, 1090 HPLC, and three 1050 HPLC's.  Two of the HPLC systems are supplemented with a software program called Chemtex, which uses pigment chromophore profiles to identify algal taxa.  Two of the HPLC systems are equipped with temperature control units (-5 degrees C to +50 degrees C). The Gas Chromatography area consists of seven Hewlett Packard gas chromatographs; dual ECD, dual FID, dual NPD, as well as various combinations of these detectors.  All GC units are equipped with 100-well autosamplers and have the ability to transfer data into spreadsheet format for ease of manipulation, tabulation, and comparisons.  This area also houses two GC-Mass Spectrometers (Agilent 5972 and 5973) equipped with 100-well autosamplers. The Metals Analysis area consists of an Inductively Coupled Plasma - Mass Spectrometer (Perkin Elmer's ELAN 6000) with autosampler that can accept up to 360 samples, a hydride generator, and spreadsheet for ease of manipulation, tabulation, and comparisons. The sample preparation areas consist of a microwave digester, rotary evaporation concentrators, soxhlett extraction racks, tissue homogenizers, sonic cell disrupters, shakers, and other laboratory equipment for the extraction, separation, and concentration of samples. The Standards Repository houses US EPA certified standards for those chemicals that have been used at GED for the last ten years, as well as the standards for current projects. See "Chemical Analysis Instruments Available for GED Researchers" for a description of equipment and capabilities available at GED.

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URL: http://www.epa.gov/ged/bld20.htm Revised: February 27, 2002