For most landfill operators, buying professional services for groundwater monitoring programs isn't an easy task. Subtitle D's groundwater monitoring regulations and ramifications for failing compliance evaluations are reason enough to seek professional sampling and analysis services (see chart).
Subtitle D requires monitoring specific groundwater pollutants. Compliance is based on the comparison of analytical results to EPA Maximum Contaminant Levels (MCLs). For parameters without MCL, background analyte concentrations from previous samplings are compared. It's the landfill owner's or operator's responsibility to meet the monitoring objectives and supply the regulating agency with accurate information.
The U.S. EPA enforces MCLs on approximately 25 percent of the 214 assessment monitoring parameters. The parameters' analytical data determines if the facility must perform higher (and more expensive) levels of groundwater monitoring. The three compliance levels imposed by Subtitle D are detection, assessment and corrective action.
Detection monitoring gathers background data for each well and requires 62 organic and inorganic analytes to be analyzed. To develop background data, the facility must be sampled four to eight times. Subsequent monitoring statistically compares each of the 62 parameters to background concentrations.
If the monitoring finds an increased concentration of one or more parameters or if analyte concentrations exceed a MCL, assessment monitoring is necessary.
Assessment monitoring programs require analyzing 214 organic and inorganic analytes in order to obtain background data on all parameters. Groundwater protection standards (GPS) must be established through the MCL or the laboratory can determine the background concentration for analytes. Next, the landfill owner or operator must either identify other sources for the pollution, discredit the data or continue with assessment monitoring, risk assessment or corrective action.
Groundwater clean-up begins if assessment monitoring indicates that correction action is needed. At this point, costs will significantly increase. For example, detection monitoring at a facility with four monitoring wells can cost about $20,000 to $40,000 per year; assessment monitoring can cost about $80,000 to $120,000 per year; and the final stage, corrective action, can require millions of dollars.
Avoiding Higher Costs Remember, higher levels and more expensive monitoring and corrective action may be required if the sampling and analysis are improperly performed. To avoid this, certain aspects should be carefully considered.
For example, once the groundwater sample is removed from the aquifer, it is subject to variations in pressure, temperature and atmospheric and biologic activity. To avoid biased analytical results, well installation and sample collection should be carefully performed and thoroughly documented.
To verify that the laboratory properly handled and preserved the samples and used accurate analytical techniques, always ask for quality control/quality assurance (QA/QC) documentation. Owners should evaluate the QA/QC data for accuracy and periodically submit performance evaluation samples to the lab.
Since the monitoring process is lengthy, it's likely that more than one laboratory will perform the analyses. Make sure the labs use the same data variables for their testing procedures.
Laboratory procurement is a critical component of the groundwater compliance program. After all, the future of the facility - both operational and financial - rests on the data from the laboratory that you select.
During the procurement process, facility owners and operators must evaluate laboratory performance and negotiate contracts. Although the costs may seem high, competition should benefit the buyer.
Although procurement laws and policies vary for each facility, the main methods include an invitation for bid, competitive negotiation or a request for proposal.
Invitations for bids often are used to find the lowest bidder. Remember, however, you are purchasing a professional service. Because the facility's future may be determined by the winning laboratory, consider its performance in addition to the costs.
Competitive negotiations and requests for proposals qualify bidders first using laboratory performance and QA/QC before negotiating costs. Requests for proposals first qualify labs on a technical basis, then consider costs during evaluation; competitive negotiations do not address costs until a qualified laboratory is selected.
The final contract should require specific laboratory performance and QA/QC documentation with a liquidated-damages clause in case the lab fails to perform.
The laboratory should pay all re-sampling and data re-analysis costs if:
* Inaccurate analytical results are produced. This should be determined by post-sampling laboratory data validation or performance evaluation samples; or,
* If the QA/QC documentation is inadequate.
The contract should include adequate insurance, professional liability and possibly a performance bond to protect the owner and operator from laboratory errors.
A Few Recommendations It is important to define which technical elements should be considered when contracting laboratory services.
Data quality objectives (DQO) specify the quality of scientifically valid and legally defensible data, characterized in terms of precision, bias, representativeness, comparability and completeness. The degree of scrutiny depends on how the data will be used. For example, data collected for compliance monitoring such as detection or assessment monitoring, requires more scrutiny than is required with general screening data.
Use the following criteria to evaluate laboratory performance during the procurement process:
* Detection and Quantitation Limits. The laboratory must perform and document proper detection and quantitation limits which are statistically defensible.
* Qualified Personnel. The subjectivity of laboratory analysis often requires professional judgment.
* Equipment. The laboratory's analytical equipment should be of good quality. Check for backup instrumentation in case the primary instrument fails. If the laboratory subcontracts work, make sure the other lab's performance is at an equivalent QA/QC level.
* QC Samples. The contract must require the lab to analyze the required QC samples and provide verifiable documentation.
Since trace quantities of contamination can be found, QC samples must be analyzed as part of the sample analysis sequences. This evaluates the extent of false positive or false negative results.
* Documentation. The laboratory should document equipment calibration logs and maintain instrument performance records.
* Records. The laboratory should maintain records of sample handling procedures during storage and analysis. In addition, look for analytical methodology records. They should be detailed enough for another qualified analyst to arrive at the same conclusion.
* Standard Procedures. The laboratory should specify which procedures are to be used for data handling, reporting, and record keeping. Laboratory documentation is required to provide defensible analytical data.
Submit performance evaluation samples to the laboratory as the final step to determine if the laboratory can meet the DQOs. If the criteria for the performance evaluation samples are met, the laboratory procurement process is finalized.