Long-term O&M costs often dwarf engineering and remedial construction costs, but they don't have to. By negotiating with regulators for adequate cleanup standards, reducing labor through automation and standardizing environmental reporting and record keeping, site owners often can shut down a system early or reduce the long term operating costs of environmental treatment systems by 30% to 50%. 

Construction of a $1 million groundwater treatment plant operated for 30 years or more, for example, typically would be preceded by five years of consulting, regulatory negotiation and engineering costs. These initial costs would total about $300,000. After construction, the O&M phase might continue for 30 years. If the initial O&M cost is $40,000 per year and the inflation rate is 3%, the true future cost of O&M exceeds $2 million, which is substantially higher than consulting, engineering and construction costs combined (see Remedy Total Cost). Even a 10% reduction in O&M costs can produce enormous savings in the long run. The following four strategies can help to lower overall O&M costs:

• Negotiate with regulators to reduce O&M requirements.
• Design a system that will require less servicing,
• Automate the system so that human factors play a minimal role in routine tasks.
• Computerize environmental data management and reporting.

Contaminant levels eventually get so low that the system can no longer reduce them. In many cases, the contaminant concentration may be higher than the cleanup standard, but continued operation of a treatment process in this situation is unwarranted, wasteful and ineffective. No discernable benefit can be obtained. 

A policy for shutting down a treatment process that is based on the rate of change of the concentration versus time could save millions of dollars in cleanup costs. This would be consistent with Californian's Containment Zone Policy. The policy, adopted in October 1996, recognizes the futility of trying to remediate groundwater to drinking water standards without considering technological and economic limitations. 

In addition, a shutdown standard based on science could justify an impracticability waiver from the U.S. Environmental Protection Agency, based on the inability of the system to achieve required cleanup levels using available remedial technology. This approach offers the owner an opportunity to shut down a system early and renegotiate sampling and reporting frequency. When a system can no longer significantly reduce the concentration of contaminants, groundwater concentrations change slowly. Frequent well sampling and monitoring are unjustified and wasteful. 

Like the automobile, environmental treatment systems have changed dramatically in the past decade. In the past, automobiles required frequent maintenance, but this maintenance could be performed by mechanics with ordinary training. Now, because automobiles include computer technology, only highly trained electronics technicians can perform tune-ups. 

Similarly, environmental treatment systems once required significant labor that was not highly specialized. Modern computerized control systems allow unmanned treatment processes to operate for longer periods without attention, except for routine maintenance analogous to changing the oil filter in a car. When more sophisticated, less frequent corrective maintenance is required, highly trained technicians equipped with modem diagnostic tools are needed. 

Newly developed procedures and technology can continue to save money for site owners well into the O&M phase of long-term environmental projects. Owners can take advantage of highly automated treatment systems that combine environmental engineering expertise with the latest computer science technology. 

The latest generation of digital field devices can gather, transmit and display information beyond simple process variable measurement. For example, they can monitor operational status and the readiness of the operating equipment. With this information, maintenance staff can perform preventive and corrective repairs in far less time and at far less cost than required by traditional, pre-digital control systems. 

The most flexible control systems are industrial computer based and run Microsoft Windows software on an Intel Pentium personal computer. Standard control components, such as General Electric Fanuc programmable logic controllers (PLCs) and the InTouch Man-Machine Interface software from Wonderware Corp., Irvine, Calif., make these systems relatively inexpensive to install and maintain. An automated control system for a typical $1 million groundwater treatment plant costs about $20,000. 

Digital field devices typically communicate with the PLC through a single communication cable. Gone is the need for an electrical engineer to prepare complicated drawings and wiring diagrams for installation and maintenance. Capital costs associated with plant engineering and construction drop dramatically. 

A supervisory control and data acquisition (SCADA) system combines telemetry and computer technology to provide centralized monitoring and control of facilities over a large geographic area. By integrating a wide area network (WAN) and the Internet with the SCADA system, technicians can monitor and adjust a system anywhere in the world, from any location. (see figure) 

Once SCADA systems are installed, plants and systems can be remotely monitored and controlled - allowing troubleshooting, system resets and diagnostic work without a site visit. The customer's local area network (LAN) can be integrated into a SCADA system to allow remote control from any workstation in the company. System security is designed to allow only the level of access that certain persons need. 

Although construction cost savings generally pay for a distributed control system in a new treatment plant, O&M savings also make retrofit of existing systems an attractive option. Many site owners have discovered that reduced maintenance labor, downtime, repair costs and monitoring, as well as compliance improvements, result in a payback period of a few months. 

Cost reduction is not the only reason to automate monitoring systems. Improved regulatory compliance may be reason enough. It is now possible to place environmental monitoring and control at the engineer's desktop computer instead of in the plant's control room. In fact, many systems are located at remote, unmanned sites and are designed using only a standard electrical cabinet to house the field components, such as a PLC. In these cases, complete operational control and monitoring of sites can be accomplished anywhere in the world from any location. 

The most compelling benefit of automated control systems is that they provide an opportunity to shut down the treatment system early. All groundwater and soil vapor extraction systems approach the cleanup goal asymptotically, or with a greater reduction in contaminant levels early in the process. The high efficiency and reliability of automated systems mean that they achieve cleanup more rapidly than other systems, thus providing an opportunity to shut them down early. 

The costs and benefits of automating environmental remediation systems can be generalized as follows: 

New construction. If integrated into a new design, an automated system can be installed at near the cost of a traditional control system, and in some cases at a significantly lower cost. Although automated control system components cost more than their analog counterparts, installation is easier, which can offset material costs. 

Existing system retrofit. If an existing monitoring or treatment system is retrofitted, costs are incurred in several areas, including engineering, construction and operator training. But once a system is automated, many benefits can be realized immediately. 

Treatment precision. Unlike a human operator, the PLC monitors and adjusts system parameters several times every second rather than hourly, daily or weekly. This precision means that the treatment technologies are always running at peak efficiency, and the system is vigilantly monitored for alarm conditions, which is critical for regulatory compliance. 

Consumables expenditure. A system that adds a chemical anti-scalant for an air stripper, for example, can use a PLC to continually monitor the chemical residual in the effluent water of the air stripper and automatically increase or decrease the amount of the chemical injected upstream to attain the desired level. The system automatically and immediately compensates for changes in flow rates and injection pump variations so that no wasteful overdosing occurs. 

Waste removal expenditure. Traditionally, technicians change water filters on a set schedule. An automated system would alert an operator to change the filters only when the differential pressure across them reached a predetermined set point, usually the point at which the degradation in filter performance begins to adversely affect system operation. When used in conjunction with a voice-call alarm system, the PLC can notify an off-site maintenance technician that its time to change the filter. 

System downtime. The PLC can be programmed to respond to alarm conditions in a way that keeps the system running. In addition, when an alarm condition occurs, the PLC can immediately notify an off-site operator of the condition. The operator can make an informed trip to the site or remotely access the system from a personal computer, make an adjustment and restart the system without a site visit. 

Data collection. The system software can be programmed to collect and store process data as often as once per second. 

Water levels can be recorded hourly, rather than during monthly site visits, providing more useful information. Daily summary reports can be generated in a word processing or spreadsheet format. This automatic data collection, when combined with preformatted documents that make real-time inquiries to the database, can dramatically reduce the time needed to generate routine monthly, quarterly and annual reports and can increase the quality and accuracy of the information contained in the reports. 

Because the systems can be monitored and adjusted at any time or at any desired interval from a desktop computer with virtually no increase in cost system reliability and environmental compliance improve dramatically. If stringent regulations and stiff penalties for permit violations are part of the picture, improved compliance can be benefit enough to justify the cost of a retrofit. The high efficiency and reliability of automated systems mean that cleanup occurs more rapidly and O&M expenses may be lower. 

Long-term operations and maintenance (O&M) costs for environmental remediation systems often dwarf engineering and remedial construction costs, but they don’t have to. By negotiating with regulators for adequate cleanup standards, reducing labor through automation, and standardizing environmental reporting and record keeping, site owners often can shut down remediation systems early or decrease long-term operating costs by 30% to 50%. Even a 10% reduction in O&M costs can produce enormous savings in the long run. Because automated systems can be monitored and adjusted at any time or at any desired interval from a desktop computer with virtually no increase in cost, system reliability and environmental compliance improve dramatically. In the end, the high efficiency and reliability of automated systems means that the approach to the cleanup level occurs more rapidly and can reduce O&M expenses.