Options for Reduced CEMS QA/QC Costs

Author:
Russell S. Berry
RMB Consulting & Research, Inc.
5104 Bur Oak Circle
Raleigh, North Carolina 27612

Presented at the 1997 EPRI CEM Users Group Meeting
Denver, Colorado
May 14-16, 1997

Abstract

Over the next three to five years, as continuous emission monitoring systems (CEMS) age, the Environmental Protection Agency (EPA) continues to revise monitoring requirements and CEMS equipment is replaced or modified, the costs associated with 40 CFR Part 75 compliance will continue to mount. In many cases, the additional costs to comply with EPA's evolving Acid Rain Program will be inevitable; however, in some cases, utilities may also be able to reduce certain costs. In particular, through the development of additional CEMS software capabilities, CEMS components, equipment designs and alternative quality assurance/quality control (QA/QC) procedures, utilities may be able to reduce operation and maintenance (O&M) costs by as much as 50 percent. To achieve such enormous cost reductions, utilities, member organizations and CEMS vendors will have to coordinate efforts to enhance all aspects of CEMS operation and maintenance.

Introduction

Relative to initial CEMS equipment, site modification, installation, startup and certification costs, the ongoing O&M costs (including all QA/QC and data reporting activities) are substantial. Depending on site modification and installation costs, O&M costs over a 10-year period may exceed initial capital costs by a factor of 3 or more. Consequently, even relatively small reductions in annual CEMS operating costs can result in significant cost reductions in the overall CEMS program costs.

When reviewing existing CEMS equipment and O&M practices, a variety of potential improvements can be identified. Furthermore, costs can be reduced using several approaches. For example, if a particular component proves to be problematic, a CEMS operator may seek to improve component performance, modify the equipment to reduce replacement labor costs, or change the system design to eliminate the component. Based on past and recent experience, a reduction in O&M cost of as much as 50 percent may be possible over the next 10 years.

Current CEMS O&M Costs

O&M costs for existing Part 75 CEMS can be categorized as costs associated with:

•Daily checks
•Routine maintenance
•Corrective maintenance
•Training
•QA/QC activities
•Data validation efforts, and
•Reporting and recordkeeping

Historically, utilities have not track these costs separately, and in many cases, company philosophy will dictate the split between routine and corrective maintenance; however, the sum of these activities for a "full" Part 75 CEMS can range from $80,000 to $120,000 annually. Based on information recently provided from eight utilities, data validation, reporting and recordkeeping efforts constitute approximately 30 to 35 percent of these costs. Daily checks, routine maintenance and training account for another 35 to 40 percent. QA/QC activities comprise approximately 20 percent, and corrective maintenance activities account for the final 10 to 15 percent. Note that these costs do not include many indirect costs such as incremental boiler operating costs incurred during relative accuracy test audits (RATA), elevator/hoist maintenance or contracted consulting services..

Areas Of Possible Improvement

Excluding the development of new types of analyzers (i.e., new principals of operation), possible means of reducing O&M costs can be categorized into four basic approaches:

1.) The automation of tasks. CEMS vendors have historically had difficulties developing and supporting quality software products. In order to reduce O&M costs significantly, CEMS related software packages must improve.

2.) Component reliability. While improving component reliability can only have a limited impact on O&M reductions, for some components, improving reliability may be the only option for reducing costs.

3.) Reduced maintenance effort. In some cases, the best approach to reducing costs will involve improved troubleshooting capabilities and equipment repair processes

4.) Alternative QA/QC activities. There are possible alternative QA/QC activities that, following proper demonstration efforts, EPA may be willing to consider.

Automation

With improved software packages, daily checks and the evaluation of daily check values can all be automated. In addition, all of the daily records could be recorded and stored electronically providing improved trending capabilities, quarterly summaries and maintenance requests. Existing software packages should also be enhanced and/or new packages developed to perform 80 to 90 percent of the data validation activities.

Recordkeeping efforts can also be reduced through the advancement of software. For example, the effort of generating and maintaining files for maintenance logs, calibration gas logs and daily calibration records could be eliminated. Standard file formats for RATA data and software that directly incorporates the RATA data into the CEMS database and EDR should also be developed.

Component Reliability

Improvements to a variety of mechanical and electronic components will also result in reduced O&M costs. As examples, some utilities are experiencing recurring probe heater problems, solenoid valve problems, critical orifice problems and flow transducer problems. Electronic components frequently causing utilities problems include power supplies, signal amplifiers and linearization circuits.

Utilities have also encountered periodic problems with materials used to create leak-free seals and adhesives used on some analyzer components. In some cases, these types of problems were due to vendors attempting to switch to cheaper materials. Where recurring material failures are identified, vendors should be notified and more reliable materials substituted.

The quality and durability of optical surfaces and light sources should also be improved. Reflective surfaces, for example, in some analyzers are easily damaged during maintenance and have a replacement cost of over $1000, and some utilities have recurring light source problems, as well.

Reduced Maintenance

In situations where component performance cannot be improved cost-effectively, equipment should be designed to facilitate the maintenance and repair of those components. In addition, troubleshooting software needs to be developed. With a 2- to 3-year CEMS O&M learning curve, continued downsizing and job turnover, troubleshooting software could significantly reduce corrective maintenance efforts.

EPA Requirements

In the next few years, EPA's continual revisions to Part 75 requirements will result in additional CEMS program costs; however, at the same time, it will provide opportunities to incorporate other software enhancements and opportunities to propose and discuss alternative QA/QC procedures with EPA. For these types of software enhancements to be fully appreciated, EPA will need to "accept" the notion that written records would not be readily available and possible alter intended on-site audit guidelines. Furthermore, RATA requirements could be reduced if other periodic interim QA procedures are shown to be adequate. For example, in lieu of a RATA for two out of every three years additional less expensive checks could be performed to leak check the sample lines and probe and confirm proper operation of the NOx converter.

Flow monitoring performance specifications and validation check requirements should also be reevaluated and redeveloped . More checks similar to the heat rate comparisons and fewer RATA, interference checks and leak checks should be performed. Alternative reporting requirements should also be discussed further with EPA.

Conclusions

Considering the level of effort required to complete the tasks discussed above and the possibility of enormous benefits to CEMS users, the following conclusions can be reached.

•In order to minimize CEMS O&M costs all aspects of a CEMS program must be improved; there is no single "fix."
•Cooperation will be required between utilities and CEMS vendors. •Utilities may want to consider funding projects through their CEMS/DAS user groups or as tailored collaboration efforts.
•Historic utility information will be extremely valuable -- from the CEMS technicians. A forum is needed to collect and review information from utilities.
•Product enhancements and incentives exist.
•A 50 percent reduction in CEMS O&M cost is possible.

RMB Consulting & Research, Inc.
Last Revised: May 22, 1998