SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

dialers to remotely contact an "on*' operator,they •Exhibit 9 can often run unattended with only weekly or biweekly checks and maintenance. Metals removal systems may General Guidelines for Labor Typically require more attention than these units,but the Re uired for Various Types of Treatment Plants chemicals required for operation may be automatically Treatment Plant Estimated Labor dosed and batched thereby reducing operator labor to 40 hours per week. System operators should be local, air stripping weekly checks by local (i.e., located within an hour from the system, if vapor phase GAC operator(8-12 possible)to quickly address potential alarms and to for offgas hours/week) minimize or eliminate per diem or travel costs. In some treatment quarterly checks by engineer cases,remote access to system data and controls by modem can further reduce operator labor. GAC treatment weekly checks by local Opportunities for increased system automation and operator(8-12 decreased operator labor can result in significant cost hours/week) savings. The table in Exhibit 9 provides general quarterly checks by guidelines,based on information gathered during engineer reviews of 20 Fund-lead P&T systems,as to the metals removal one or two operators amount of labor typically required for various types of filtration full time(1 or 2 x 40 treatment plants. hours/week) A number of factors can affect these guidelines. For metals removal two operators full time example, additional labor may be required if substantial filtration (2 x 40 hours/week) maintenance is required for recurring issues, such as air stripping GAC well or system fouling due to iron bacteria. Very few systems should require more than 2 full time operators, and with proper automation, sites should not require a 24-hour presence. included during the design or early in O&M,when frequent sampling was necessary for system Eliminate Excess Process Monitoring "shakedown". However,the need for this frequent sampling may be eliminated when the system reaches Process monitoring is generally required to demonstrate steady-state or continuous operation. Except in rare the effectiveness of the treatment plant but can be cases, a reduced number of samples can be analyzed in costly if laboratory analysis is required. Therefore, an independent off-site laboratory with a one-week or excess process monitoring should be eliminated, and even 24-hour turnaround time for a lower cost than the when possible sensors should be used to determine the labor and materials required to maintain and staff an performance of the treatment components. Many on-site laboratory or calibrate and operate commonly used treatment technologies, such as air sophisticated equipment. strippers and granular activated carbon,have been used successfully and reliably for years and minimal If frequent sampling is required for a treatment plant monitoring is necessary to demonstrate their during"shakedown", a temporary period of on-site effectiveness once the system is operating. In many monitoring could be arranged if cost-effective cases,a metals removal system can be effectively compared to sending samples off site. This approach operated based on sensor readings of total suspended is generally more cost effective than arranging and solids and oxidation-reduction potential, and its staffing a permanent laboratory.. performance can be cost-effectively evaluated by analyzing samples from the plant effluent for metals. E. CONTRACTING CONSIDERATIONS Process monitoring samples that are collected are generally most cost-effectively analyzed in off-site An O&M contract for a P&T system should clearly laboratories. Although the use of inexpensive field kits outline the responsibilities of the O&M contractor. are often beneficial and cost-effective as screening However,because of changing site conditions, level data, the use of staffed on-site laboratories or progress toward site closure, and optimization sophisticated on-site analytical equipment, such as gas opportunities, the contract should also allow for chromatographs, are often not cost effective over time. reductions in the scope of work. Such laboratories or equipment may have been 16