(All pictures may be viewed at original resolution by clicking on each.)
| Operating in the field environment requires
extensive preparation. Equipment and information resources need to be
well organized and within easy reach of the field technician. Samples
must be collected using clean quality-assured equipment and processed
for shipment to the analytical laboratory onsite. Field measurements
such as pH, specific conductance, temperature, dissolved oxygen,
alkalinity, and indicator bacteria need to be measured and processed
immediately. To assist the USGS technician, the Missouri District has
developed a mobile field laboratory that can be mounted on any standard
pickup truck with a 6- to 8-foot bed. These mobile laboratories are
constructed of wood with aluminum siding. They contain both heater and air
conditioning. Cabinetry and countertops are custom manufactured from a
Lexan material. The mobile laboratory is a well-organized unit that the technician
can use to maintain a clean, uncompromised
sample processing environment.
The field laboratory is designed to allow the technician to work either standing or sitting. Typically two technicians will be in the laboratory at the same time. One will process the sample for shipment to the analytical laboratory and make the necessary field measurements, and the other will complete the shipping documents--these include the bill of lading, chain-of-custody, and analytical services request forms.
All of the laboratories are on four-wheel drive trucks equipped with diesel engines. Diesel engines were selected because of long periods of idle the vehicle is under during the sample processing period. Also, diesel engines are designed to haul heavy loads and --the weight of the lab and equipment approaches the limits of the vehicle. The Water-Quality Data & Analysis Section maintains five mobile laboratories of this configuration, and two vans equipped with countertops. The van are used during emergency situations when all the other field vehicles are being used.
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Water-quality Data & Analysis Section field vehicles are equipped with a custom front-mount boom that is designed to position a sample-collection crane over a bridge rail, shown below in the closed 'travel' position. The crane can be assembled in about 15 minutes. No tools are necessary--all connections are slotted and held together by gravity and the weight of sampler suspension.
The following picture shows the sample-collection crane fully extended with a 3-liter frame sampler, a Price current meter, and a 15-pound sounding weight attached. The technician operates the crane from the position shown. The reels attached to the crane can be operated either by hand or by electric motor. The choice of using the hand crank or the electric motor is the decision of the technician and it is based on the size of the sounding weight used, the distance from the bridge deck to the water surface, and the depth of the stream or river.
Maintaining a clean laboratory interior means keeping all non-process related equipment out of the laboratory. Most of the bare metallic equipment used in the field for stream gaging, sample collection, and safety are stored in the side-mounted tool box that is built into the outside of the lab. This tool box also is used to store miscellaneous power and hand tools.
The Water-Quality Data & Analysis Section has been able to collect and process samples for its large sampling networks in a timely and accurate manner. This in part is the result of having dedicated water-quality mobile laboratories at its disposal. These vehicles will continue to be a valuable logistical resource to the USGS data collection program. |
U.S. Department of the Interior, U.S. Geological Survey
Maintainer: Rita Choate, Webmaster
Updated: August 27, 2003
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URL: http://missouri.usgs.gov/wtrqual/mobile_laboratories.htm
