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AOC 65 Soil Vapor Extraction System - Operation and Maintenance Plan

Section 4 - System Operation and Monitoring

4.1 - System Start-up

The following items comprise a system start-up list:

	Check that moisture separator(s) is not full;
	Open FCVs to extract from desired VEWs and close, if desired, any FCVs to VEWs not desired;
	Check condition and operation of equipment and repair or replace as needed;
	Adjust vacuum relief/bleed valve(s) to maximum vacuum allowed (generally 55 in. H2O) to protect blower(s) from mechanical damage; and
	Start-up blower(s) and adjust FCVs to balance flows from VEWs in service, as desired.

4.2 - Operation and Monitoring

The primary operating activities include monthly and quarterly monitoring of system performance, and twice monthly monitoring of equipment operation. Parsons will take measurements and data for the initial six months of operation under Task Order 0058. Performance data will be used to determine system effectiveness for the Assessment Report while equipment data will be used as it is gathered to maintain equipment in good operating condition.

The operation and monitoring work described in this section include:

1. Monthly determination of soil vapor/emissions at the seven SVE VEWs, both blowers, and the GAC adsorber;

2. Monthly monitoring of flow rates, and vacuum pressures in the individual VEW flow streams, and at the equipment;

3. Twice monthly drive-by system checks of the equipment and piping network to adjust, repair and replace components as needed to maintain the systems in good operating condition; and

4. Quarterly monitoring and data collection of individual well flows and air emissions from both systems.

These data will all be recorded on one of the two data collection sheets in Appendix A.

4.3 - Performance Data

To monitor the performance of the blowers, the inlet vacuum, the outlet pressure, and outlet temperature will be monitored on each blower on a twice-monthly basis. All measurements should be taken at the same time, while the system is running. (Note: Because the blowers are noisy, hearing protection may need to be worn when working around the blowers).

4.3.1   VEW, Exhaust Emissions and Soil Vapor

Blowers and knockout pots will be monitored twice monthly. Every other system check will correspond with the monthly monitoring effort, during which VEWs and equipment points will be checked for VOC, oxygen and carbon dioxide concentrations.

4.3.2   Quarterly Data Collection

Soil vapor samples and emission samples will be collected on a quarterly basis for off-site analyses to confirm trends and field measurements. All such vapor samples (emissions and soil) will be tested for VOCs by Method TO-14. The CSSA Quality Assurance Program Plan (QAPP) will be followed for sample collection, analysis, and data validation. Samples will be collected at the beginning of O & M, after three months (Quarter 1), and after six months when the initial O&M period is complete (Quarter 2).

4.3.3   Flows and Pressures

During operation of the two systems, flows and vacuum pressures from each SVE VEW will be measured and recorded biweekly. The FCVs will be adjusted to balance the flow as desired. If maintaining flow from the critical VEWs (those with high VOC removal rates) is not possible in then Parsons will determine which VEWs should be shut off to maximize removals.

4.4 - Operation/Maintenance Monitoring

4.4.1   Twice Monthly and Monthly Monitoring Visits

Twice monthly system checks will be performed to assure that system operation is satisfactory. A check of the systems includes visual inspection of the equipment and the piping network for cracks, separations, holes and other problems. Each of the well-heads and pipe joints will also be inspected for leaks or weakness of structure. Blower operation, filter cleanliness and VRV operation and lubrication will also be checked or be done. Finally, these visits include assessment and management of any accumulated liquid in the moisture separators.

4.4.2   Vent Well Air Flow Rate

The flow rate into each vent well is calculated using direct measurements of in-line air velocity and pipe size data. Air velocity is measured by placing an anemometer into the air measurement port located on each vent well pipe. The volumetric flowrate is calculated by multiplying the velocity obtained times the cross-sectional area of the pipe. Flow data allow more accurate adjustment of the FCVs at each vent well to balance flows through the system.

4.5 - Monitoring Schedule

The following monitoring schedule is proposed for these systems.

Table 4.1 - Monitoring Schedule

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