Landfill managers can benefit from monitoring techniques used in other municipal utilities. What you do and don't know about what's going on in your operation can make the difference in avoiding crises, controlling costs, and all-around management. In addition, new monitoring technology and software can help with reporting and regulatory compliance.

By Penelope Grenoble O'Malley

Richard Henry runs a 650-ac. landfill outside of Provo, UT. The air is hot and dry, the rainfall slight, and the regulatory environment informal. Trash comes to the landfill via medium haul from a transfer station 30 mi. away, where an attendant weighs it (no trash delivery allowed on-site). The landfill receives about 500 tons on a good day, and Henry is currently in the process of opening the second of what he expects will be 10 cells. He figures he's got more land than he'll ever use. As of yet there is no landfill gas system (projections are not for another 16 years), the bottom of the landfill is on average 150 ft. from the local water table, and the sparse rainfall means stormwater is not a problem–ditto with leachate. Henry reports that a few years ago the lining of the leachate pond blew off and had to be repaired. A page from the past? Not much to worry to about? Henry worries nonetheless.

"The facility is relatively isolated, and we've got a lot of land, so it would be very easy just to take the attitude that, since we're never going to bother anybody, we can just do what we want out there. But we don't know what's down the road. Maybe someday there will be people living right next to us, maybe they'll need the land for something. And if we've ruined it so that everything around it is no longer useable...."

The landfill Henry manages for the South Utah Valley Solid Waste District outside of Provo was the first in the state to install a liner, and that was before state law required it. These days Henry and the municipal board that oversees the six-city district are beginning to think about composting and recycling (again with no state mandate staring them in the face), and with the first cell just short of being buttoned up, Henry thinks he might install the infrastructure for the gas system that's scheduled down the road. He's also considering a global positioning system (GPS) to track trash and compaction and eventually monitor gas. He sums up the district's philosophy in a nutshell: "Let's do it right so that, as much as we can see what regulations are coming, we can meet them and not have to go back and redo things."

The Future Is Here

Dick Sprague, director of landfill services for HDR Inc. in Denver, CO, describes the current thinking about landfill management Henry exemplifies as simple responsible environmental stewardship and forecasts that in the years to come automated data management will likely be the key to this kind of landfill operation. "For one thing," says Sprague, "the International Organization of Standardization [ISO] has established standards and a certification process for environmental stewardship, which require continuous improvement. We're going to have to move there eventually, either through regulation or this type of international standard, and our clients who are looking toward ISO certification realize they will need data demonstrating they're meeting this goal of continuous environmental improvement."

Sprague takes as his model other municipal utilities, such as water districts, wastewater management, and transportation systems, where real-time monitoring keeps operators up to date on the status of entire systems. "If you go into a wastewater or waste-to-energy plant, there'll be a complete control room with data feed coming in from everywhere–all the pump stations in the treatment plant, all the blowers, all the temperature and oxygen probes, all the chemical feeds–so the operator can instantly know what's going on everywhere in his plant." In terms of landfill management, Sprague projects this would likely mean flow monitors on landfill gas system laterals, high-water alarms for leachate collection systems, and perhaps eventually automated groundwater monitoring–all done simultaneously and all computer-controlled, with telemetering or hard-wire transmission of data from multiple sites to a central point. Operators will know about a problem as soon as it occurs–a gas flare down, a pump malfunctioning–and will be able to take immediate steps to remedy the situation.

"If you know a pump station's down, you can deal with it before it's an emergency," says Sprague. "As it stands now, if there's a problem in any of the systems, we don't have a good way of knowing what caused it. In other utilities, operators use data partly to prevent emergencies and partly to provide a baseline of operating information. In the long run, we'll need systems like these to provide data as we move into bioreactors, which are intensely managed landfills. If you're adding water to a bioreactor, according to proposed regulations, you'll need to know how much you've added and how much head is on the liner, for example, which will probably mean telemetering capabilities in distribution and collection sumps and similar data collection and transmission.

"Our clients who have gotten involved in landfill gas control tell us their most advanced piece of equipment on the landfill is the landfill gas system. It's all computer-controlled with data transmitted into a central location. If a flare goes down, someone gets a call. Other clients have telemetering on their pump stations, but this isn't common yet, which means this had not yet been a common problem, partly because leachate pumping is relatively new technology. It's still the case that if a pump goes down, an operator may not know about it until the morning. I'm not sure that technology is available and proven to enable real-time groundwater monitoring and data telemonitoring, but stormwater ponds will probably require a high-water alarm or something of that sort in the not-too-distant future. Right now there aren't cost-effective ways of detecting groundwater contamination, and although it may be expensive to deal with, groundwater typically doesn't move quickly."

Bob Hauser, senior vice president at Camp Dresser & McKee Inc. in Tampa, FL, shares Sprague's version of the future and cautions that some of what he's forecast has already arrived. "Your leachate collection and construction systems are more sophisticated than they ever were," says Hauser. "Permitting is much more detailed in terms of the records you need to keep and how you need to keep them. And we have the bioreactor coming, which will mean, among other things, measuring temperature, gas production, the amount of water put back into the site, and where it goes. Where you used to have to send somebody out there to turn a pump on or off or open and shut a valve or manipulate the level of water in a stormwater pond, these procedures can now be done remotely from a central location. Air monitors are being put in around landfills that can be digitized and remotely set off.

"These automated systems give you more information. As the systems become more efficient and the cost comes down and the computer systems become better, you'll be seeing more and more of this occurring. Eventually it will extend to other systems–we're seeing some of that now–lighting, operation manuals, O&M [operations and maintenance] procedures being computerized. We've made advances in landfill design and those types of things, but information and management tools are really where the technology has been growing. What all this amounts to is better management control information, as opposed to necessarily saving bundles of money." And as Hauser observes, none of this would be feasible without computers. "With all this monitoring data, there's a lot of information to manipulate. Computers are much better at doing this. The main thing is that you're keeping all this information in electronic files, and the software programs give you the capability to manipulate it and bring it out in the form that you want. Maybe the big boss downtown only wants a one- or two-page summary of what's going on, but someone more involved wants the whole report."

Brian Horvatch, senior project manager in the Chicago, IL, office of Weaver Boos & Gordon Inc., is not as enthusiastic about the brave new world Hauser and Sprague are predicting. "Yes, landfills as a whole are probably behind other utilities," says Horvatch, "but part of the reason relates to the nature of landfilling. A landfill is really just a construction site. You install your liner system and then you build your landfill to final grade with waste. Also, a landfill is a pretty aggressive environment. Our researchers have had difficulty losing instruments and control wires because of filling or construction activities. And not only do you have waste down there but you have more aggressive liquid than you would have, say, in a drinking-water plant. There's no question that with the technology we have today we could do a better job of automating functions at the landfill surface, especially things like gas wellheads. But for monitoring inside the landfill itself, we still have some problems with the technology that's available."

Horvatch is also concerned about the amount of information that might be generated. "A landfill is very heterogeneous. Let's say you had instrumentation throughout the landfill to measure leachate head level, which is not supposed to be higher than a foot, rather than taking measurements at the traditional two to five locations. Conceivably you might find locations where the level is higher than it should be. The difficulty comes in interpreting the information–maybe it's just bad data, maybe it's a very localized condition, or maybe there really are problems with the system."

Right Out of the Gate

All three experts agreed that the first place automation is likely to be implemented in a landfill is at the gate. Dylan Hardy, North American marketing manager for Mettler Toledo, says software-controlled scales have become a standard in the industry and the current trend is toward unattended scale operations. "Landfill managers are obviously thinking about ways to reduce costs and improve throughput. One way to do this is with automated scales. If you have a site that's truly unattended, we can supply a system with a full-blown touch screen that drivers interact with like an ATM, with buttons and directions that force them to move through the transaction with no room for deviations. Landfill managers need to remember that truck scales are the landfill cash register. They need to be able to control their transactions relatively quickly and effectively and maintain control of their cash at the same time as their site. With the type of software we offer, they can know in a blink of an eye how many transactions they have open, which also means they know how many open trucks are on-site."

In Dallas, TX, Jennifer Stafford, business analysis for the city's solid waste disposal district, wanted software that could streamline financial transactions and produce reports required by the state environmental agency. Faced with having to build a new scale house at the city landfill, which receives 6,500 tpd, the district decided to install a systemwide software package combined with unattended scales. "We wanted the software to handle the monetary and financial side of the landfill and transfer station activities," she explains, "but also to help us evaluate our management efficiency." Stafford chose WasteWORKS from Carolina Software and installed an attendant-free WasteWIZARD automatic keypad control unit at the landfill and two of the transfer stations. Previously recordkeeping for billing was done manually with "people writing on cards and bringing them back and then someone else adding up the totals. Maybe they did it right, maybe they didn't," says Stafford. "An automated format is much more reliable. It's also faster.

"The unattended system works because there's no money handled at our transfer stations–only our city collection trucks use them. At the landfill we have two inbound lanes: one primarily for cash customers, the other a Wizard lane for credit customers, which includes our trucks and our large customers who pay monthly. Our outbound lane can also be used as inbound if traffic backs up. I would tend to guess that a lot of operations underutilize their software because they view it as a means to keep track of their cash. But there's so much more business-related information that we have found invaluable. The software enables us to enter material codes so we know what's coming in and we can relate those codes to tonnages so we know the weight; or if it's tires, how many. We need this information for the state resource conservation commission; before we didn't have the ability to report accurately. We can also use the program's cell grid to know where in a cell a certain kind of material has been dumped."

Sacramento County has four WasteWIZARD installations, including a fully automated transfer station.

At the Sacramento County Department of Waste Management and Recycling, where weights were also previously entered by hand, Doug Kobold says the combination of WasteWIZARDs and WasteWORKS software has been "a godsend." The operation includes two transfer stations and a landfill, with one Wizard box at the landfill (150 out of 400 transactions a day are automated), two at one of the transfer stations, one on the inbound scale, one on the transfer scale, and one at the second transfer station, which is a completely unmanned site. "We're running a 24-hour-a-day operation," notes Kobold, "and with the Wizard boxes, we don't need three shifts. We use the software to do our billing and our report to the state and our DOE [Department of Energy] forms. Before I would have to select out all the materials. Now it's done by just running a material-type report. At this point we could have any clerk do it–all they need to know is the type of report we're requiring and then plug in the line items."

Software for Groundwater Monitoring

The ability to generate reports and automate statistical analysis is a reason to apply DUMPStat software from Discerning Systems in Vancouver, BC, to landfill groundwater monitoring functions. "The way it works in a nutshell," describes Mark Verwiel, director of groundwater protection for Waste Management in Oakland, CA, "is that you collect background chemistry information, and from that data you calculate a limit. Then you compare all your future measurements to that limit. If you exceed the limit, the program thrusts you into another form of evaluating the data." Verwiel was involved in the development of the software and says Waste Management's goal was a program that would do "thousands of measurements simultaneously. We have approximately 170 landfills that require these kinds of statistics, and we're actually doing routine analysis on maybe 60%. The other 40% are still in the process of developing background information, which we require them to do over a period of two years. The difference between surface water and landfill gas is that there is a lot more technical analysis required. With landfill gas, there's four components; with groundwater, thousands. I have probably 50 sites in our Western states loaded on my computer, and I look at the data on a regular basis. If there's a problem, I'll pull up the software and evaluate what I'm seeing, and this allows me to give quick direction to our consultant, who is also running the same software." Verwiel is excited about the next generation, DUMPStat Explorer, which he says will do scatter plots and regression analysis along with various other statistical functions.

DUMPStat's worksheet viewer, allowing a "look under the hood" at the calculations performed in generating the graphical and tabular output. Click here for large view.

In Snohomish County, WA, Dave Schonhard uses DUMPStat to monitor groundwater in six postclosure municipal landfills.

"Landfill data don't fit the standard bell curve, which most statistics need it to do," he states. "What happens is you end up with skewed data. To solve this problem, the DUMPStat software basically analyzes the data set. If the data fits a bell curve, it uses standard statistics, but if it doesn't, it automatically selects the appropriate statistical calculations for a given data set. This feature is invaluable for me because we may be doing 150 parameters at each landfill, each with its unique data set.

"Another thing we wanted was the ability to easily import data. With older landfills, you get a very large base of environmental data. We've given our DUMPStat requirements to the laboratory so that what comes back from them meshes seamlessly with our system. There's no data transfer, which keeps unnecessary errors out of the system. When I look at the data in DUMPStat and see an anomaly, I can go right back to the lab report and check: Is this real? When we're doing a report and we see a high reading somewhere, we can readily investigate it. Washington has changed its postclosure requirements since we closed these landfills, some of which date back to the 1970s. Right now we're doing a wide variety of general chemistry, pretty much a full range of metals and a very wide range of volatile organics. And because we're a closed landfill, we're doing all of this sampling on a quarterly basis.

"We don't have telemetry bringing back real-time data from the groundwater wells, but we do have data telemetered from our leachate systems. We have a leachate treatment plant and gas-flaring facility all automated through a separate system, and we're able to integrate that data into DUMPStat. Now we're trying to get the local health district to use the same software so we can send them our data and actually do in-depth analysis of our facilities beyond what's required by law. With this software, they could focus on a particular well or they can do interwell analysis."

Air and Radiation Monitoring Up Next

As Hauser notes, landfill air monitoring is also on the docket using systems such as those provided by Air Logic, which brings its equipment on-site and sets up a complete perimeter monitoring system. A central "acquisition" station pools the data, which are then measured against a previously established baseline. The system has been used on demolition jobs, at gas manufacturing plants, and at nuclear facilities, and the company is looking to expand into the landfill market.

Explorer's multiline time series plots concentration of multiple constituents at a single well or of a single constituent at multiple wells. Click here for a larger view.

In light of recent efforts to step up domestic security, also look for states to require monitoring of radioactive materials. According to Gary Wascovich, product specialist for Thermo RMP (formerly Saint-Gobain Crystals & Detectors in Solon, OH), Pennsylvania was the first state to require radiation monitoring, although New York City has had a law on the books since the 1980s. Maryland also has a similar law, and Mark Freedman of the Montgomery County Resources Recovery Facility in Dickerson, MD, says Thermo RMP's full truck monitoring system has been installed at the facility and at the transfer station that delivers waste to the recovery site. The equipment identifies the type of radioisotope present, if any, in effect differentiating between medical waste and something more serious. If the isotope identified is long-lived, radiation specialists are called in. "We get one or two hits a week," reports Freedman, "and since we started doing this in November 2001, we've had two hits that weren't medical. In both cases it was cobalt 60. In both cases, we couldn't identify the origin of the waste because the load wasn't tested until it got up here. The equipment was installed here first so they didn't know to check where it came from at the transfer station."

Hauser, Horvatch, and Sprague each noted a trend among progressive landfill managers for aerial surveys of landfill sites to determine airspace and to meet regulations for postclosure funding. "If you survey from year to year, you can look back from one year to the next and see where the site's being filled, the height, and what capacity you have left," points out Hauser; Sprague observes that some managers are doing aerial surveying quarterly or even monthly. The photographs can be manipulated using computer software to produce a three-dimensional image that can be utilized to document fill history and to plan continued fill. "Most people aren't going to print out a 3D picture of their landfill every month," notes Hauser, "but when you want it or need it, it's there." As an alternative, Sprague says some of HDR's clients are looking toward GPS for the same purpose, taking a daily reading at the toe of the working face as a starting point to define daily volumes. An additional benefit is that this also generates a record of where the loads for a given day are located–information that might turn out to be valuable. "One of our clients is doing just that, taking a defined point on the working face once a day," relates Sprague. "A little girl just disappeared in his service area. He has been visited by police detectives who requested his records showing the license plate number of all vehicles disposing of wastes during a defined period of time. He's concerned that he's going to be asked to dig her up. This is a terrible thing, but it doesn't get better if you don't find the body. It would cost him money to implement a GPS system, but part of the payoff would be not having to spend thousands of dollars digging up on a large scale what you've already compacted. The landfill in Colorado, for example, which did not have GPS data, was only able to approximately locate the possible burial site of one body in a family multiple murder. They dug for 51 days, found one body but not the second." Everyone also agreed that GPS could be valuable for tracking illegal waste that is deliberating or accidentally disposed of into the regular wastestream.

Another use of GPS is remote monitoring of landfill operations. Sprague describes a client who is considering adding GPS to this landfill equipment (cost: about 10% of a $350,000 compactor plus telemetering and data collection equipment). "You're selling airspace," says Sprague. "You want to know that your operators are doing the best they can do to maximize it. This particular client, who sits 35 road miles from his landfill, is thinking of GPS as a tool to help him assure his elected body they're spending their money the best way they can. And once you start telemetering things like GPS over 30 miles, you can telemeter other things like flow in the leachate system. This gives you a track record of data, and if nothing else a record of continuous data makes people feel comfortable because it shows that you are in control of the situation."

Why haven't automated monitoring and surveying systems made inroads before this? As one industry insider put it, "It's human nature in a very competitive market not to spend money that would make you noncompetitive. Which means some of this will have to be regulatory- or standards-driven: There has to be a hammer that hurts enough that it would pay for centralized monitoring. What kind of a hurt? Like a leachate pump station that overflows into a river."

"If a large sewage pump station goes down," say Sprague, "the results can be disastrous, so for decades pump stations have had telemetry. We haven't had those kinds of situations with landfills, so we haven't moved to those kinds of control room—type systems, but we're going to have to eventually. If people don't move there voluntarily, standards or regulations will push them."

Penelope Grenoble O'Malley is a frequent contributor to MSW Management.

MSW - November/December 2002