RELATIONAL MANAGEMENT and DISPLAY of SITE ENVIRONMENTAL DATA - PART 3 potx

This chapter provides an overview of the regulations that drive the siteinvestigation and remediation process, some information on how the process works under themajor environmental regu

PART THREE - GATHERING ENVIRONMENTAL DATA

CHAPTER 10

SITE INVESTIGATION AND REMEDIATION

The site investigation and remediation process is usually the reason for site environmental datamanagement The results of the data management process can provide vital input in the decision-making process This chapter provides an overview of the regulations that drive the siteinvestigation and remediation process, some information on how the process works under themajor environmental regulations, and how data management and display is involved in thedifferent parts of the process Related processes are environmental assessments and environmentalimpact statements, which can also be aided by an EDMS

OVERVIEW OF ENVIRONMENTAL REGULATIONS

The environmental industry is driven by government regulations These regulations have beenenacted at the national, state, or local level Nearly all environmental investigation and remediationactivity is performed to satisfy regulatory requirements A good overview of environmentalregulations can be found in Mackenthun (1998) The following are some of the most significantenvironmental regulations:

National Environmental Policy Act of 1969 (NEPA) – Requires federal agencies to consider

potentially significant environmental impacts of major federal actions prior to taking the action.The NEPA process contains three levels of possible documentation: 1) Categorical Exclusion(CATEX), where no significant effects are found, 2) Environmental Assessment (EA), whichaddresses various aspects of the project including alternatives, potential impacts, and mitigationmeasures, and 3) Environmental Impact Statement (EIS), which covers topics similar to an EA, but

in more detail

Clean Air Act of 1970 (CAA) – Provides for the designation of air quality control regions,

and requires National Ambient Air Quality Standards (NAAQS) for six criteria pollutants(particulate matter, sulfur dioxide, carbon monoxide, ozone, nitrogen dioxide, and lead) Alsorequires National Emission Standards for Hazardous Air Pollutants (NESHAPs) for 189 hazardousair pollutants The act requires states to implement NAAQS, and requires that source performancestandards be developed and attained by new sources of air pollution

Occupational Safety and Health Act of 1970 – Requires private employers to provide a

place of employment safe from recognized hazards The act is administered by the OccupationalSafety and Health Administration (OSHA)

Endangered Species Act of 1973 (ESA) – Provides for the listing of threatened or

endangered species Any federal actions must be evaluated for their impact on endangered species,and the act makes it illegal to harm, pursue, kill, etc a listed endangered or threatened species

Safe Drinking Water Act of 1974 (SDWA) – Protects groundwater aquifers and provides

standards to ensure safe drinking water at the tap It makes drinking water standards applicable toall public water systems with at least 15 service connections serving at least 25 individuals.Requires primary drinking water standards that specify maximum contamination at the tap, andprohibits certain activities that may adversely affect water quality

Resource Conservation and Recovery Act of 1976 (RCRA) – Regulates hazardous wastes

from their generation through disposal, and protects groundwater from land disposal of hazardouswaste It requires criteria for identifying and listing of hazardous waste, and covers transportationand handling of hazardous materials in operating facilities The act also covers construction,management of, and releases from underground storage tanks (USTs) In 1999, 20,000 hazardouswaste generators regulated by RCRA produced over 40 million tons of hazardous waste (EPA,2001b) RCRA was amended in 1984 with the Hazardous and Solid Waste Amendments (HSWA)that required phasing out land disposal of hazardous waste

Toxic Substances Control Act of 1976 (TSCA) – Requires testing of any substance that may

present an unreasonable risk of injury to health or the environment, and gives the EPA authority toregulate these substances Covers the more than 60,000 substances manufactured or processed, butexcludes nuclear materials, firearms and ammunition, pesticides, tobacco, food additives, drugs,and cosmetics

Clean Water Act of 1977 (CWA) – Based on the Federal Water Pollution Control Act of

1972 and several other acts Amended significantly in 1987 This act, which seeks to eliminate thedischarge of pollutants into navigable waterways, has provisions for managing water quality andpermitting of treatment technology Development of water quality standards is left to the states,which must set standards at least as stringent as federal water quality standards

Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA, Superfund) – Enacted to clean up abandoned and inactive hazardous waste sites.

Creates a tax on the manufacture of certain chemicals to create a trust fund called the Superfund.Sites to be cleaned up are prioritized as a National Priority List (NPL) by the EPA Procedures andcleanup criteria are specified by a National Contingency Plan The NPL originally contained 408sites, and now contains over 1300 Another 30,000 sites are being evaluated for addition to the list

Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA) – Enacted

after the Union Carbide plant disaster in Bhopal, India in 1984, in which release of methylisocyanate from a chemical plant killed 2,000 and impacted the health of 170,000 survivors, thislaw requires industrial facilities to disclose information about chemicals stored onsite

Pollution Prevention Act of 1990 (PPA) – Requires collection of information on source

reduction, recycling, and treatment of listed hazardous chemicals Resulted in a Toxic ReleaseInventory for facilities including amounts disposed of onsite and sent offsite, recycled, and used forenergy recovery

These regulations have contributed significantly to improvement of our environment Theyhave also resulted in a huge amount of paperwork and other expenses for many organizations, andexplain why environmental coordinators stay very busy

Bad regulations are more likely to be supplemented than repealed

Rich (1996)

THE INVESTIGATION AND REMEDIATION PROCESS

The details of the site investigation and remediation process vary depending on the regulationunder which the work is being done Superfund was designed to remedy mistakes in hazardouswaste management made in the past at sites that have been abandoned or where a sole responsibleparty cannot be determined RCRA deals with sites that have viable operators and ongoingoperations The majority of sites fall into one of these two categories The rest operate under arange of regulations through various different regulatory bodies, many of which are agencies in thevarious states

CERCLA

CERCLA (Superfund) gives the EPA the authority to respond to releases or threatenedreleases of hazardous substances that may endanger human health and the environment The threemajor areas of enforcement at Superfund sites are: achieving site investigations and cleanups led

by the potentially responsible party (PRP) or parties (PRP lead cleanups, meaning the lead party

on the project is the PRP); overseeing PRP investigation and cleanup activities; and recoveringfrom PRPs the costs spent by EPA at Superfund cleanups (Fund lead cleanups)

The National Contingency Plan of CERCLA describes the procedures for identification,evaluation, and remediation of past hazardous waste disposal sites These procedures arepreliminary assessment and site inspection; Hazard Ranking System (HRS) scoring and NationalPriority List (NPL) site listing; remedial investigation and feasibility studies; record of decision;remedial design and remedial action; construction completion; operation and maintenance; andNPL site deletion Site environmental data can be generated at various steps in the process.Additional information on Superfund enforcement can be found in EPA (2001a)

Preliminary assessment and site inspection – The process starts with investigations of site

conditions A preliminary assessment (PA) is a limited scope investigation performed at each site.

Its purpose is to gather readily available information about the site and surrounding area to

determine the threat posed by the site The site inspection (SI) provides the data needed for the

hazard ranking system, and identifies sites that enter the NPL site listing process (see below) SIstypically involve environmental and waste sampling that can be managed using the EDMS

HRS scoring and NPL site listing – The hazard ranking system (HRS) is a numerically

based screening system that uses information from initial, limited investigations to assess therelative potential of sites to pose a threat to human health or the environment The HRS assigns anumerical score to factors that relate to risk based on conditions at the site The four risk pathwaysscored by HRS are groundwater migration; surface water migration; soil exposure; and airmigration

HRS is the principal mechanism EPA uses to place uncontrolled waste sites on the National

Priorities List (NPL) Identification of a site for the NPL helps the EPA determine which sites

warrant further investigation, make funding decisions, notify the public, and serve notice to PRPsthat EPA may begin remedial action

Remedial investigation and feasibility studies – Once a site is on the NPL, a remedial

investigation/feasibility study (RI/FS) is conducted at the site The remedial investigation involves

collection of data to characterize site conditions, determine the nature of the waste, assess the risk

to human health and the environment, and conduct treatability testing to evaluate the potentialperformance and cost of the treatment technologies that are being considered The feasibility study

is then used for the development, screening, and detailed evaluation of alternative remedial actions.The RI/FS has five phases: scoping; site characterization; development and screening ofalternatives; treatability investigations; and detailed analyses The EDMS can make a significantcontribution to the site characterization component of the RI/FS, which often involves a significantamount of sampling of soil water and air at the site The EDMS serves as a repository of the data

as well as a tool for data selection and analysis to support the decision-making process Part of thesite characterization process is to develop a baseline risk assessment to identify the existing orpotential risks that may be posed to human health and environment at the site The EDMS can bevery useful in this process by helping screen the data for exceedences that may represent riskfactors.

Record of decision – Once the RI/FS has been completed, a record of decision (ROD) is

issued that explains which of the cleanup alternatives will be used to clean up the site This publicdocument can be significant for data management activities because it often sets target levels forcontaminants that will be used in the EDMS for filtering, comparison, and so on

Remedial design and remedial action – In the remedial design (RD), the technical

specifications for cleanup remedies and technologies are designed The remedial action (RA)

follows the remedial design and involves the construction or implementation phase of the sitecleanup The RD/RA is based on specifications described in the ROD The EDMS can assistgreatly with tracking the progress of the RA and determining when ROD limits have been met

Construction completion – A construction completion list (CCL) helps identify successful

completion of cleanup activities Sites qualify for construction completion when any physicalconstruction is complete (whether or not cleanup levels have been met), EPA has determined thatconstruction is not required, or the site qualifies for deletion from the NPL

Operation and maintenance – Operation and maintenance (O&M) activities protect the

integrity of the selected remedy for a site, and are initiated by the state after the site has achieved

the actions and goals outlined in the ROD The site is then determined to be operational and

functional (O&F) based on state and federal agreement when the remedy for a site is functioning

properly and performing as designed, or has been in place for one year O&M monitoring involvesinspection; sampling and analysis; routine maintenance; and reporting The EDMS is used heavily

in this stage of the process

NPL site deletion – In this final step, sites are removed from the NPL once they are judged to

no longer be a significant threat to human health and the environment To date, not many sites havebeen delisted

RCRA

The EPA’s Office of Solid Waste (OSW) is responsible for ensuring that currently generatedsolid waste is managed properly, and that currently operating facilities address any contaminantreleases from their operations In some cases, accidents or other activities at RCRA facilities havereleased hazardous materials into the environment, and the RCRA Corrective Action Programcovers the investigation and cleanup of these facilities Additional information on RCRAenforcement can be found in EPA (2001b)

As a condition of receiving a RCRA operating permit, active facilities are required to clean upcontaminants that are being released or have been released in the past EPA, in cooperation withthe states, verifies compliance through compliance monitoring, educational activities, voluntaryincentive programs, and a strong enforcement program The EDMS is heavily involved incompliance monitoring and to some degree in enforcement actions

Compliance monitoring – EPA and the states determine a waste handler’s compliance with

RCRA requirements using inspections, record reviews, sampling, and other activities The EDMScan generate reports comparing sampling results to regulatory limits to save time in the compliancemonitoring process

Enforcement actions – The compliance monitoring process can turn up violations, and

enforcement actions are taken to bring the waste handler into compliance and deter furtherviolations These actions can include administrative actions, civil judicial actions, and criminalactions In addition, citizens can file suit to bring enforcement actions against violators or potentialviolators

One important distinction from a data management perspective between CERCLA and RCRAprojects is that CERCLA projects deal with past processes, while RCRA projects deal with bothpast and present processes This means that the EDMS for both projects needs to store information

on soil, groundwater, etc., while the RCRA EDMS also might store information on ongoingprocesses such as effluent concentrations and volumes, and even production and other operationalinformation

Other regulatory oversight

While many sites are investigated and remediated under CERCLA or RCRA, other regulatoryoversight is also possible The EPA has certified some states to oversee cleanup within theirboundaries In some cases, other government agencies, including the armed forces, oversee theirown cleanup efforts In general, the technical activities performed are pretty much the sameregardless of the type of oversight, and the functional requirements for the EDMS are also the sameThe main exception is that some of these agencies require the use of specific reporting tools asdescribed in Chapter 5

ENVIRONMENTAL ASSESSMENTS AND ENVIRONMENTAL IMPACT STATEMENTS

The National Environmental Policy Act of 1969 (NEPA), along with various supplementallaws and legal decisions, requires federal agencies to consider the environmental impacts andpossible alternatives of any federal actions that significantly affect the environment (Mackenthun,

1998, p 15; Yost, 1997, p 1-11) This usually starts with an environmental assessment (EA) The

EA can result in a determination that an environmental impact statement (EIS) is required, or in a

finding of no significant impact (FONSI) The EIS is a document that is prepared to assist with

decision making based on the environmental consequences and reasonable alternatives of theaction The format of an EIS is recommended in 40 CFR 1502.10, and is normally limited to 150pages Often there is considerable public involvement in this process

One important use of environmental assessments is in real estate transactions The seller andespecially the buyer want to be aware of any environmental liabilities related to the property being

transferred These assessments are broken into phases The data management requirements of EAs

and EISs vary considerably, depending on the nature of the project and the amount and type of dataavailable

Phase 1 Environmental Assessment – This process involves evaluation of existing data

about a site, along with a visual inspection, followed by a written report, similar to a preliminaryassessment and site inspection under CERCLA, and can satisfy some CERCLA requirements such

as the innocent landowner defense The Phase 1 assessment process is well defined, and guidelinessuch as Practice E-1527-00 from the American Society for Testing and Materials (ASTM 2001a,2001b), are used for the assessment and reporting process There are four parts to this process:gathering information about past and present activities and uses at the site and adjoining properties;reviewing environmental files maintained by the site owner and regulatory agencies; inspection ofthe site by an environmental professional; and preparation of a report identifying existing andpotential sources of contamination on the property The work involves document searches andreview of air photos and site maps Often the source materials are in hard copy not amenable todata management Public and private databases are available to search ownership, toxic substancerelease, and other information, but this data is usually managed by its providers and not by theperson performing the search Phase 1 assessments for a small property are generally not long orcomplicated, and can cost as little as $1,000

Phase 2 Investigation – If a Phase 1 assessment determines that the presence of

contam-ination is likely, the next step is a Phase 2 assessment The primary differences are that Phase 1relies on existing data, while in Phase 2 new data is gathered, usually in an intrusive manner, andthe Phase 2 process is less well defined This can involve sampling soil, sediment, and sludge andinstallation of wells for sampling groundwater This is similar to remedial investigation andfeasibility studies under CERCLA If the assessment progresses to the point where samples arebeing taken and analyzed, then the in-house data management system can be of value

Phase 3 Site Remediation and Decommissioning – The final step of the assessment process,

if necessary, is to perform the cleanup and assess the results Motivation for the remediation mightinclude the need to improve conditions prior to a property transfer, to prevent contamination frommigrating off the property, to improve the value of the property, or to avoid future liability.Monitoring the cleanup process, which can involve ongoing sampling and analysis, will usuallyinvolve the EDMS

CHAPTER 11

GATHERING SAMPLES

AND DATA IN THE FIELD

Environmental monitoring at industrial and other facilities can involve one or more differentmedia The most common are soil, sediment, groundwater, surface water, and air Other media ofconcern in specific situations might include dust, paint, waste, sludge, plants and animals, andblood and tissue Each medium has its own data requirements and special problems Generatingsite environmental data starts with preparing sampling plans and gathering the samples and relateddata in the field There are a number of aspects of this process that can have a significant impact onthe resulting data quality Because the sampling process is specific to the medium being sampled,this chapter is organized by medium Only the major media are discussed in detail

GENERAL SAMPLING ISSUES

The process of gathering data in the field, sending samples to the laboratory, analyzing thedata, and reporting the results is complicated and error-prone The people doing the work are oftenoverworked and underpaid (who isn’t), and the requirements to do a good job are stringent.Problems that can lead to questionable or unusable data can occur at any step of the way Theexercise (and in some cases, requirement) of preparing sampling plans can help minimize field dataproblems Field sampling activities must be fully documented in conformance with project qualityguidelines Those guidelines should be carefully thought out and followed methodically A fewgeneral issues are covered here The purpose of this section is not to teach field personnel toperform the sampling, but to help data management staff understand where the samples and datacome from in order to use it properly In all cases, regulations and project plans should be followed

in preference to statements made here Additional information on these issues can be found inASTM (1997), DOE/HWP (1990a), and Lapham, Wilde, and Koterba (1985)

Taking representative samples

Joseph (1998) points out that the basic premise of sampling is that the sample must representthe whole population, and quotes the law of statistical regularity as stating that “a set of subjectstaken at random from a large group tends to reproduce the characteristics of that large group.” Butthe sample is only valid if the errors introduced in the sampling process do not invalidate theresults for the purpose intended for the samples Analysis of the samples should result in no biasand minimum random errors

Types of Sampling Patterns

Simple Random Sampling Judgment Sampling

Grid (Systematic) Sampling Stratified Sampling

Random Grid Sampling Two-Stage Sampling

KnownPlume

PrimaryStage

SecondaryStage

B A

Figure 51 - Types of sampling patterns

The size of the sample set is directly related to the precision of the result More samples costmore money, but give a more reliable result If you start with the precision required, then thenumber of samples required can be calculated:

2 2

2

) 4 /

N

Ns n

Care should be taken so that the sample locations are as representative as possible of theconditions being investigated For example, well and sample locations near roadways may beinfluenced by salting and weed spraying activities Also, cross-contamination from dirty samplesmust be avoided by using procedures like sampling first from areas expected to have the leastcontamination, then progressing to areas expected to have more

Logbooks and record forms

Field activities must be fully documented using site and field logbooks The site logbook

stores information on all field investigative activities, and is the master record of those activities

The field logbook covers the same activities, but in more detail The laboratory also should keep a

logbook for tracking the samples after they receive them

The field logbook should be kept up-to-date at all times It should include information such aswell identification; date and time of sampling; depth; fluid levels; yield; purge volume, pumpingrate, and time; collection methods; evacuation procedures; sampling sequence; container types andsample identification numbers; preservation; requested parameters; field analysis data; sampledistribution and transportation plans; name of collector; and sampling conditions

Several field record forms are used as part of the sampling process These include Sample

Identification and Chain of Custody forms Also important are sample seals to preserve the

integrity of the sample between sampling and when it is opened in the laboratory These are legaldocuments, and should be created and handled with great care

Sample Identification forms are usually a label or tag so that they stay with the sample Labels

must be waterproof and completed in permanent ink These forms should contain such information

as site name; unique field identification of sample, such as station number; date and time of samplecollection; type of sample (matrix) and method of collection; name of person taking the sample;sample preservation; and type of analyses to be conducted

Chain of Custody (COC) forms make it possible to trace a sample from the sampling event

through transport and analysis The COC must contain the following information: project name;signature of sampler; identification of sampling stations; unique sample numbers; date and time ofcollection and of sample possession; grab or composite designation; matrix; number of containers;parameters requested for analysis; preservatives and shipping temperatures; and signatures ofindividuals involved in sample transfer

COC forms should be enclosed in a plastic cover and placed in the shipping container with thesamples When the samples are given to the shipping company, the shipping receipt number should

be recorded on the COC and in the site logbook All transfers should be documented with thesignature, date, and time on the form A sample must remain under custody at all times A sample

is under custody if it is in the sampler’s possession; it is in the sampler’s view after being inpossession; it is in the possession of a traceable carrier; it is in the possession of anotherresponsible party such as a laboratory; or it is in a designated secure area

SOIL

Taking soil samples must take into consideration that soil is a very complex physical material.

The solid component of soil is a mix of inorganic and organic materials In place in the ground,soil can contain one or more liquid phases and a gas phase, and these can be absorbed or adsorbed

in various ways The sampling, transportation, and analysis processes must be managed carefully

so that analytical results accurately represent the true composition of the sample

Soil sampling issues

Before a soil sample can be taken, the material to be sampled must be exposed For surface orshallow subsurface soil samples this is generally not an issue, but for subsurface samples thisusually requires digging This can be done using either drilling or drive methods Forunconsolidated formations, drilling can be done using an auger (hollow-stem, solid flight, orbucket), drilling (rotary, sonic, directional), or jetting methods For consolidated formations, rotarydrilling (rotary bit, downhole hammer, or diamond drill) or cable tools can be used Drive methodsinclude cone penetrometers or direct push samplers

Sometimes it is useful to do a borehole geophysical survey after the hole is drilled Examples

of typical measurements include spontaneous potential, resistivity, gamma and neutron surveys,acoustic velocity, caliper, temperature, fluid flow, and electromagnetic induction

Soil samples are gathered with a variety of tools, including spoons, scoops, shovels, tubes, andcores The samples are then sealed and sent to the laboratory Duplicates should be taken asrequired by the QAPP (quality assurance project plan)

Sometimes soil samples are taken as a boring is made, and then the boring is converted to amonitoring well for groundwater, so both soil and water samples may come from the same hole inthe ground

Typical requirements for soil samples are as follows The collection points should be surveyedrelative to a permanent reference point, located on a site map, and referenced in the field logbook

A clean, decontaminated auger, spoon, or trowel should be used for each sample collected Surface

or air contact should be minimized by placing the sample in an airtight container immediately aftercollection The sampling information should be recorded in the field logbook and any otherappropriate forms

For subsurface samples, the process for verifying depth of sampling, the depth controltolerance, and the devices used to capture the samples should be as specified in the work plan Caremust be taken to prevent cross-contamination or misidentification of samples

Sometimes the gas content of soil is of concern, and special sampling techniques must be used.These include static soil gas sampling, soil gas probes, and air sampling devices

Velilind’s laws of Experimentation: 1 If reproducibility may be a problem, conduct the testonly once 2 If a straight line fit is required, obtain only two data points

McMullen (1996)

Special consideration should be given for soil and sediment samples to be analyzed for volatileorganics (VOAs) The samples should be taken with the least disturbance possible, such as usingCalifornia tubes Use Teflon or stainless steel equipment If preservatives are required, they should

be added to the bottle before sampling Samples for VOA analysis should not be split Air bubblescannot be present in the sample The sample should never be frozen

Soil data issues

Soil data is usually gathered in discrete samples, either as surface samples or as part of a soilboring or well installation process Then the sample is sent to the laboratory for analysis, which can

be chemical, physical, or both Each sample has a specific concentration of each constituent ofconcern Sometimes it is useful to know not only the concentration of a toxin, but also its mobility

in groundwater Useful information can be provided by a leach test such as TCLP (toxicitycharacterization leaching procedure), in which a liquid is passed through the soil sample and theconcentration in the leachate is measured This process is described in more detail in Chapter 12.Key data fields for soil samples include the site and station name; the sample date and depth;COC and other field sample identification numbers; how the sample was taken and who took it;transportation information; and any sample QC information such as duplicate and otherdesignations For surface soil samples, the map coordinates are usually important For subsurfacesoil samples, the map coordinates of the well or boring, along with the depth, often as a range (topand bottom), should be recorded Often a description of the soil or rock material is recorded as thesample is taken, along with stratigraphic or other geologic information, and this should be stored inthe EDMS as well

SEDIMENT

Procedures for taking sediment samples are similar to those for soil samples Samples should

be collected from areas of least to greatest contamination, and from upstream to downstream.Sediment plumes and density currents should be avoided during sample collection

GROUNDWATER

Groundwater is an important resource, and much environmental work involves protecting andremediating groundwater A good overview of groundwater and its protection can be found inConservation Technology Resource Center (2001) Groundwater accounts for more than 95% of allfresh water available for use, and about 40% of river flow depends on groundwater About 50% ofAmericans (and 95% of rural residents) obtain all or part of their drinking water from groundwater

Groundwater samples are usually taken at a location such as a monitoring well, for an

extended period of time such as quarterly, for many years Additional information on groundwatersampling can be found in NWWA (1986) and Triplett (1997)

Groundwater or Ground Water?

Is “groundwater” one word or two? When used by itself, groundwater as one word looks fine,and many people write it this way The problem comes in when it is written along withsurface water, which is always two words, and ground water as two words looks better Someindividuals and organizations prefer it one way, some the other, so apparently neither is right

or wrong For any one writer, just as with “data is” vs “data are,” the most important thing is

to pick one and be consistent

Figure 52 - Submersible sampling pump (Courtesy of Geotech Environmental Equipment)

Groundwater sampling issues

The first step in groundwater sampling is to select the location and drill the hole Drillingmethods are similar to those described above in the section on soil sampling, and soil samples can

be taken when a groundwater well is drilled Then the wellbore equipment such as tubing, screens,and annular material is placed in the hole to make the well The tubing closes off part of the holeand the screens open the other part so water can enter the wellbore Screening must be at thecorrect depth so the right interval is being sampled

Prior to the first sampling event, the well is developed For each subsequent event it is purgedand then sampled The following discussion is intended to generally cover the issues ofgroundwater sampling The details of the sampling process should be covered in the project workplan Appropriate physical measurements of the groundwater are taken in the field The sample isplaced in a bottle, preserved as appropriate, chilled and placed in a cooler, and sent to thelaboratory

Well development begins sometime after the well is installed A 24-hour delay is typical.

Water is removed from the well by pumping or bailing, and development usually continues untilthe water produced is clear and free of suspended solids and is representative of the geologicformation being sampled Development should be documented on the Well Development LogForm and in the site and field logbooks Upgradient and background wells should be developedbefore downgradient wells to reduce the risk of cross-contamination

Measurement of water levels should be done according to the sampling plan, which may

specify measurement prior to purging or prior to sampling Groundwater level should be measured

to a specific accuracy (such as 0.05 ft) and with a specific precision (such as 0.01 ft).Measurements should be made relative to a known, surveyed datum Measurements are taken with

a steel tape or an electronic device such as manometer or acoustical sounder Some wells have apressure transducer installed so water levels can be obtained more easily

Figure 53 - Multi-parameter field meter (Courtesy of Geotech Environmental Equipment)

Some wells contain immiscible fluid layers, called non-aqueous phase liquids (NAPLs) There

can be up to three layers, which include the water and lighter and heavier fluids

The lighter fluids, called light non-aqueous phase liquids (LNAPLs) or floaters, accumulate above the water The heavier fluids, called dense non-aqueous phase liquids (DNAPLs) or sinkers,

accumulate below the water For example, LNAPLs like gasoline float on water, while DNAPLssuch as chlorinated hydrocarbons (TCE, TCA, and PCE) sink NAPLs can have their own flowregime in the subsurface separate from the groundwater The amount of these fluids should bemeasured separately, and the fluids collected, prior to purging For information on measurement ofDNAPL, see Sara (1994, p 10-75)

Purging is done to remove stagnant water in the casing and filter pack so that the water

sampled is “fresh” formation water A certain number of water column volumes (such as three) arepurged, and temperature, pH, and conductivity must be monitored during purging to ensure thatthese parameters have stabilized prior to sampling Upgradient and background wells should bepurged and sampled before downgradient wells to reduce the risk of cross-contamination.Information concerning well purging should be documented in the Field Sampling Log

Sampling should be done within a specific time period (such as three hours) of purging, if

recharge is sufficient, otherwise as soon as recharge allows The construction materials of thesampling equipment should be compatible with known and suspected contaminants Groundwatersampling is done using various types of pumps including bladder, gear, submersible rotor,centrifugal, suction, or inertial lift; or with a bailed rope Pumping is usually preferred over bailingbecause it is takes less effort and causes less disturbance in the wellbore An example of asubmersible pump is shown in Figure 52

Field measurements should be taken at the time of sampling These measurements, such as

temperature, pH, and specific conductance, should be taken before and after the sample is collected

to check on the stability of the water during sampling Figure 53 shows a field meter for takingthese measurements The field data (also known as the field parameters) is entered on the COC,and should be entered into the EDMS along with the laboratory analysis data Sometimes thelaboratory will enter this data for the client and deliver it with the electronic data deliverable

At all stages of the sampling process it is critical that contamination of the samples beprevented Contamination can be minimized by properly storing and transporting samplingequipment, keeping equipment and bottles away from sources of contamination, using clean handsand gloves to handle equipment and bottles, and carefully cleaning the purging and samplingequipment after use.

If sampling is for VOAs (volatile organic analysis) then equipment or processes that canagitate and potentially volatilize samples should be avoided Sampling methods such as bottom-filling bailers of stainless steel or Teflon and/or Teflon bladder pumps should be used

Powell and Puls (1997) have expressed a concern that traditional groundwater samplingtechniques, which are largely based on methods developed for water supply investigations, may notcorrectly represent the true values or extent of a plume For example, the turbidity of a sample isoften related to the concentration of constituents measured in the sample, and sometimes this may

be due to sampling methods that cause turbulence during sampling, resulting in high concentrationsnot representative of in-situ conditions Filtering the sample can help with this, but a betterapproach may be to use sampling techniques that cause less disturbance of materials in thewellbore Small diameter wells, short screened intervals, careful device insertion (or the use ofpermanently installed devices), and low pump rates (also known as low-flow samples) areexamples of techniques that may lead to more representative samples

Preservation and handling of the samples is critical for obtaining reliable analytical results.

Groundwater samples are usually treated with a preservative such as nitric, sulfuric, orhydrochloric acid or sodium hydroxide (depending on the parameter) to stabilize the analytes, andthen cooled (typically to 4°C) and shipped to the laboratory The shipping method is importantbecause the analyses must be performed within a certain period (holding time) after sampling Thepreservation and shipping process varies for different groups of analytes See Appendix D for moreinformation about this

Groundwater data issues

The sample is taken and often some parameters are measured in the field such as temperature,

pH, and turbidity Then the sample is sent to the laboratory for analysis When the field andlaboratory data are sent to the data administrator, the software should help the data administratortie the field data to the laboratory data for each sampling event

Key data fields for groundwater data include the site and station name, the sample date andperhaps time, COC and other field sample identification numbers, how the sample was taken andwho took it, transportation information, and any sample QC information such as duplicate andother designations All of this data should be entered into the EDMS

SURFACE WATER

Surface water samples have no purging requirements, but are otherwise sampled and

transferred the same as groundwater samples Surface water samples may be easier to acquire, sothey may be taken more often than groundwater samples

Surface water sampling issues

Surface water samples can be taken either at a specific map location, or at an appropriatelocation and depth The location of the sample should be identified on a site map and described inthe field logbook Samples should progress from areas of least contamination to worstcontamination and generally from upstream to downstream The sample container should besubmerged with the mouth facing upstream (to prevent bubbles in the sample), and sample

information should be recorded in the field logbook and any other appropriate forms The devicesused and the process for verifying depth and depth control tolerance should be as specified in theproject work plan.

Surface water data issues

The data requirements for surface water samples are similar to groundwater samples Forsamples taken in tidal areas, the status of the tide (high or low) should be noted

DECONTAMINATION OF EQUIPMENT

Equipment must be decontaminated prior to use and re-use The standard operating procedurefor decontamination should be in the project work plan The decontamination process is usuallydifferent for different equipment The following are examples of equipment decontaminationprocedures (DOE/HWP 1990a) For nonsampling equipment such as rigs, backhoes, augers, drillpipe, casing, and screen, decontaminate with high pressure steam, and if necessary scrub withlaboratory-grade detergent and rinse with tap water For sampling equipment used in inorganicsampling, scrub with laboratory-grade detergent, rinse with tap water, rinse with ASTM Type IIwater, air-dry, and cover with plastic sheeting For sampling equipment used in inorganic ororganic sampling, scrub with laboratory-grade detergent, rinse with tap water, rinse with ASTMType II water, rinse with methanol (followed by a hexane rinse if testing for pesticides, PCBs, orfuels), air-dry, and wrap with aluminum foil

SHIPPING OF SAMPLES

Samples should be shipped in insulated carriers with either freezer forms (“blue ice”) or wetice If wet ice is used, it should be placed in leak-proof plastic bags Shipping containers should besecured with nylon reinforced strapping tape Custody seals should be placed on the containers toverify that samples are not disturbed during transport Shipping should be via overnight expresswithin 24 hours of collection so the laboratory can meet holding time requirements

AIR

The data management requirements for air sampling are somewhat different from those of soil

and water because the sampling process is quite different While both types of data can (and oftenshould) be stored in the same database system, different data fields may be used, or the same fieldsused differently, for the different types of data As an example, soil samples will have a depthbelow ground, while air samples may have an elevation above ground Typical air qualityparameters include sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, and lead Otherconstituents of concern can be measured in specific situations Sources of air pollution includetransportation, stationary fuel combustion, industrial processes, solid waste disposal, and others.For an overview of air sampling and analysis, see Patnaik (1997) For details on several airsampling methods, see ASTM (1997)

Air sampling issues

Concentrations of contaminants in air vary greatly from time to time due to weatherconditions, topography, and changes in source input Weather conditions that may be important