In the weeks before water quality samples are collected according to an approved sampling plan, several steps must be taken. Steps 4 through 8 describe these activities.

Clean sample containers, preservatives and coolers are generally provided by the laboratory in the United States. Contact the laboratory about a month before the sampling date to schedule analyses and container shipment or pickup. Use chain-of-custody procedures when coolers and containers are prepared, sealed and shipped. They will remain sealed until used in the field. When making arrangements with the laboratory, make sure you request enough containers, including those for blank and duplicate samples. Order extra sample bottles to allow for breakage or contamination in the field.

Some samples require low-temperature storage and/or preservation with chemicals to maintain their integrity during shipment and before analysis in the laboratory. The most common preservatives are hydrochloric, nitric, sulfuric and ascorbic acids, sodium hydroxide, sodium thiosulfate, and biocides. Many laboratories provide pre-preserved bottles filled with measured amounts of preservatives. Although most federal and state agencies allow the use of pre-preserved sample containers, some may require either cool temperatures or added preservatives in the field (see STEP 11).

When the containers and preservatives are received from the laboratory, check to see that none have leaked. Be aware that many preservatives can burn eyes and skin, and must be handled carefully. Sampling bottles should be labeled with type of preservative used, type of analysis to be done and be accompanied by A Material Safety Data Sheet (MSDS). Make sure you can tell which containers are pre-preserved, because extra care must be taken not to overfill them when collecting samples in the field. Check with the laboratory about quality control procedures when using pre-preserved bottles.

Coolers used for sample shipment must be large enough to store containers, packing materials and ice. Obtain extra coolers, if necessary. Never store coolers and containers near solvents, fuels or other sources of contamination or combustion. In warm weather, keep coolers and samples in the shade.

Obtaining representative samples of surface water and ground water commonly requires large amounts of equipment. Make sure you are prepared. This is especially important if the sampling site is far from your office, making it difficult to replenish supplies or pick up forgotten items. Assemble, check and calibrate your equipment within twenty-four hours of the sampling time. In addition, re-calibrate the pH and dissolved oxygen meters in the field before use. The checklist of supplies on the following pages is a useful guide for many sampling projects.

Check all electronic equipment and batteries for proper operation. Inspect glass thermometers for column separation. Make sure tubing lengths are sufficient for depths to water. Discard cracked or discolored lengths of tubing or wires. If you have any doubts about the condition of a piece of equipment, bring along a replacement. This will save you a long trip back to the office or the possibility of violating QA/QC guidelines.

Obtaining a representative sample also means being careful in your choice of equipment. If you are sampling for the presence of heavy metals, do not use samplers with metal components. When sampling for organics, avoid using samplers with plastic components, as the plastic may adsorb and contaminate the samples. Most importantly, always decontaminate equipment before use. Once the equipment is decontaminated, wrap inorganic equipment in plastic and organic equipment in aluminum foil for transport to the site.

WATER SAMPLING SUPPLIES CHECKLIST

Field Survival

 Map of station locations

 Business card or ID

 Authorization (letter, etc.)

 Field notebook

 Waterproof pens, markers and pencils

 Masking tape and rubber bands

 Trip routing forms

 Road log

 Photo log forms

 Field data forms

 Chain of custody forms

 Other forms

 Keys or security codes for gates and locks

 Graphite lubricant (not oil or WD-40) for locks and well caps

 First aid kit, knife

 Insect repellent (wash hands thoroughly after applying)

 Hat, sunscreen, drinking water

 Sunglasses or safety glasses

 Leather gloves

 Steel-toed boots, rubber boots and/or waders

 Rain gear

 Toolbox with basic tools

 Tape measure

 Flashlight and extra batteries

 2-way radio/cellular phone

 Binoculars

 Weather radio

 Uniform

 Rope

 Fire extinguisher (type B)

 Helmet or hard hat

Physical Positioning

 Camera, film

 Topographic map

 Tape measure

 Aerial photograph (optional)

 Global positioning system (optional)

Specialized Health and Safety

 Tyvek suits, non-contaminating gloves, tape, goggles, respirator, extra filters

 Explosimeter or photoionization meter

Field Parameter Measurement

 Stopwatch

 Calculator

 Non-mercuric thermometers (2)

 pH meter and buffers, pH indicator strips

 Turbidimeter

 Rain gauge

 Temperature, Conductivity, Redox, Dissolved Oxygen meters, probes and batteries

 Appropriate Hach kit(s)

 Flow-through cell

 Copies of manufacturers manuals for field equipment

 1.8 m (6-ft) wooden engineers ruler

Surface Water

 Flow meter, rod and tape measure

 DH-81 sampler (with Teflon nozzle and gasket for VOCs)

 Van Dorn or Kemmerer bottle and string

 D-77 for large streams

 Glass mason jars, 1-quart

 Churn splitter

 Decontaminated spade

 Life jacket

Ground Water

 Electric water level probe or graduated (3 mm/0.01 foot) tape with water indicator paste, gel, non-ferrous cyanide chalk or ­popper'

 Non-leaded weights

 Clear plastic bailer (for oil)

 Interface probe

 Pipe threader, pipe adapters, faucets or valves

 Containers for purged water

 Pipe wrench

 Pump and tubing

 Electric generator for pump

 Compressed air for pump

 Calibrated bucket

Sampling

 Sealed coolers and sample containers

 Bags of ice

 Maximum/minimum non-mercuric thermometers (one per cooler)

 Folding table

 Polyethylene plastic sheets (1 per station)

 Paper towels, KIM-wipes, oil sorbent pads

 Teflon-lined screw caps (for radon, volatile and semi-volatile organics

 Sodium thiosulfate or ascorbic acid (for volatile organics if chlorine is present)

 Preservatives (i.e. HNO3, HCL, H2SO4, HgCl2)

 Residual chlorine test kit

 Glass vials (for radon and volatile organics)

 Amber glass bottle (for semi-volatile organics)

 Concentrated sulfuric acid (for phenols, oil and grease)

 Filters, 0.45 microns (for dissolved metals)

 Plastic bottles and screw caps (for metals)

 Ascorbic acid and sodium hydroxide pellets (for cyanide)

 Disposable latex or nitrile gloves

Microbial Sampling

 Ziploc plastic bags (1 gallon size)

 Disposable nitrile gloves

 Filtration equipment, tubing, pump, flowmeter

 Filters

 Sterilized Whirl-pak bags (for fecal coliform and E. Coli samples)

 Sterile and buffered water

 Teflon tweezers

 Bactericidal soap

 Bacteria sample rack

Cleaning/Decontamination

 Alconox non-phosphate detergent

 Carboy-tap water (1 gallon per well)

 Carboy-deionized water (2 gallons per well)

 Carboy-HPLC grade, organic-free water (0.5 gallon per well)

 Squeeze bottle for DI water

 0.1N nitric acid rinse (when sampling for metals)

 Pesticide-grade solvent, such as hexane (when sampling for volatile or non-volatile compounds)

 10% sodium thiosulfate solution (0.25 gallon for viral sampling)

 Chlorine bleach (1 gallon for viral sampling)

 Hand-pump sprayers for washing fluids

 Decontamination vessel (plastic garbage can)

 Aluminum foil

 Plastic garbage bag for disposable equipment

Other

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All equipment that makes contact with a water-quality sample or station must be carefully cleaned before reuse. Examples are pumps, tubing, DH-81 samplers, filtration equipment, water-level probes or tapes, interface probes and clear product bailers. Filters, however, are discarded after use. The Region 9 office of EPA recommends cleaning sampling equipment using the following decontamination procedure (EPA, August 1993, "Preparation of a U.S. EPA Region 9 Sample Plan for EPA-Lead Superfund Projects," EPA Region 9, Quality Assurance Management Section, San Francisco, CA):

1. Wash with non-phosphate detergent;
2. Rinse with tap water;
3. Rinse with 10% nitric acid solution (if cross-contamination from metals is a concern);
4. Rinse with deionized/distilled water;
5. Rinse with pesticide-grade solvent (when semivolatile and non-volatile organic contamination may be present);
6. Rinse twice with deionized/distilled water;
7. Rinse with HPLC-grade, organic-free water;
8. Air dry or blow out with nitrogen in dust-free environment; and
9. Wrap cleaned inorganic equipment in plastic and cleaned organic equipment in aluminum foil for transport to the site.

If several sets of sampling tools are available, such as one for each station, then decontamination can be performed in batches at the beginning or end of a sampling day. This saves time and reduces the number of field blanks necessary.

Field equipment used to monitor physical parameters must be calibrated before water-quality samples can be taken. Because of the variety of instrumentation used in water-quality sampling, always read the manufacturer's instructions about equipment operation and calibration. Take copies of all the manufacturers' manuals with you to the site. In addition, manuals describing calibration procedures for temperature, pH, electrical conductivity, dissolved oxygen and turbidity meters also are available from the U.S. Geological Survey (USGS) and ADEQ. Document calibration results according to these procedures and record the results in the field notes.

Step 8-A: Physical Positioning
Step 8-B: Determining Station Coordinate
Step 8-C: Photographing the Station

The location and identification number of a water quality sampling station (monitoring point) should be accurately marked on a large-scale map as an X, circle, or dot. This not only enables field personnel to easily find the stations but also allows the data to be digitized into a computer database. In the United States, USGS topographic quadrangles at a scale of 1:24,000 are commonly used. In Mexico, topographic quadrangles at a scale of 1:50,000 are available from Instituto Nacional de EstadÈstica GeografÈa e Informötica (INEGI). Other scales can be used, with some industrial facilities available at larger scales (e.g., 1:2,400). In addition, drawing site sketches which show roads, buildings, trees and other landmarks not shown on topographic quadrangles helps locate remote stations for others.

If the sampling station is not shown on a map, then determine its location by physical positioning.

A. Physical Positioning

Positioning is accomplished by measuring in meters or feet the horizontal distance between the station (such as the well casing) and other physical features, measuring that distance on a map, and marking the location with an X, circle, dot or other symbol. Useful features for reference on topographic quadrangles are roads, buildings, power lines, surface waters, or abrupt changes in slope. Sketch the station and its surroundings in the field log book.

Common devices for measuring distances are listed below, in order of decreasing accuracy:

1. Triangulation
2. Electronic distance measurer
3. Tape measure
4. Hip-chain distance measurer
5. Distance measuring wheel
6. Rangefinder
7. Global positioning system
8. Pacing
9. Vehicle odometer

Other less direct methods such as visually estimating a station's location on low-altitude aerial photographs also may be used if measurement on the ground is impractical.

B. Determining Station Coordinate

To comply with national standards of data management, measure and record coordinate in units of degrees, minutes, seconds, and fractions of seconds of latitude and longitude. Location coordinates usually are measured in one of four ways. The least expensive is overlaying a scale template on the station location in the topographic quadrangle, using coordinates such as UTM, and reading the degrees, minutes and seconds along the north-south (latitude) and east-west (longitude) axes. The second is hiring a professional land surveyor. The third is digitizing locations from a map using Geographic Information System (GIS) technology. The fourth is using a portable global positioning system (GPS) device.

GIS technology has grown in popularity as a data management and mapping tool. Station coordinates in latitude/longitude or other projection can be obtained with a GIS by digitizing their locations from a paper or mylar map, with coordinates such as a USGS quadrangle. Digitizing simply means marking that point with a magnetic cursor on a digitizing table. The accuracy of the method is only as good as the accuracy of the map and the mapped location. A large number of points or areas can be digitized with a GIS in a short time.

A global positioning system consist of a portable receiver or transponder that receives coded transmissions from an array of navigational satellites. The accuracy of location coordinates depends on satellite geometry, number and transmission frequencies. Other factors, such as interference from nearby buildings, hills, vegetation and electrical power lines may also affect accuracy. Coordinates may be obtained at a station after about 4 or 5 minutes, and the data can be stored in the unit for retrieval later. Accuracy is improved when satellite transmissions are also monitored by a nearby base station.

C. Photographing the Station

In October 1992, ADEQ established guidelines for photographing surface water quality sampling stations. The guidelines are presented below and preserve most of the language from ADEQ, and are adapted for both surface and ground water quality sampling stations.

Photograph Fixed Station Sites on a regular basis for site documentation purposes. Take enough photos on the first visit to the site to establish a complete photo record of the site and its surroundings. (This also will assist a first-time visitor in locating the site.) After the first visit, take photos according to the procedures outlined below.

Take photos at each visit to the site from established and constant photopoints. The preferred photopoint is naturally occurring, such as a large tree or boulder. For example, the photographer can put his or her back against a specific tree trunk to take one of the required photographs at each visit to the site. If naturally occurring landmarks are unavailable at a given site, try to mark the photopoint in some durable yet unobtrusive and temporary way, such as with a pile of rocks. At the first visit to the site describe the photopoints in detail in the field notes. Record field notes in the site files as a permanent part of the file.

Include a person in the photo of the sample point to show scale. For a surface water station, take two photos using Kodachrome slide film (K-64) from 1) upstream of the sample point looking downstream at the sample point; and 2) downstream of the sample point looking upstream at the sample point.

Take additional photos if you notice any significant change in the site area, such as severe channel scour, severe deposition, recent construction or other biological or ecological changes that warrant documentation. Emphasize in the photos, those aspects that are likely to impact water quality.

Upon receipt of the processed slides, label them with the following information: site ID, site name, date and time, and the orientation of photo. Put the slides from each particular site into an 8-1/2 by 11 inch (21.6 by 27.9 mm) vinyl chloride slide sleeve and store them in their respective site file.

On the last visit to a site, retake the same photos that were taken on the first visit (from the same photopoints) in order to document the changes that occurred over the lifetime of the site.