Basic Audit Information

As part of most landfill audits, some basic information should be included. While it might seem to be a moot point to discuss such issues as weather data and tonnage at your own landfill, the fact is that many of the landfill’s tasks will be based on this simple information. Also, others will gain more benefit from the audit if they have a clearer background of the site. Here are some examples of how to collect and present this type of general information.

Weather Data

The Internet is a great source of weather information. The US Department of Commerce National Oceanic and Atmospheric Administration is a good place to begin looking. Weather and its effect on the operation of the landfill will impact various parts of the audit.

Precipitation data can help you to evaluate and predict landfill costs related to drainage, soil handling, ADC, and so on.

One way that this type of information can be used in an audit is to compare the monthly “dryness” to the water truck’s hours. If the water truck is used for dust control at your landfill, there will be (should be) a correlation. Here’s how it works:

At many landfills, the water truck is used for clay-liner construction, for machine washing, and/or to provide moisture for the compost operation, along with spraying roads for dust control. However, for this analysis, we’ll be addressing only the water truck’s use to control dust on the site’s access roads.

Using the “inverse of precipitation” data, it’s possible to come up with a general estimate of how many hours the water truck works at providing dust control. As a general rule of thumb, the water truck works between 50-100 times the inverse of precipitation. This is an empirical relationship and is, of course, subject to variations in soil type, temperature, amount of traffic, and so on. However, many landfills fall into this range.

When leading into your audit, you’ll also want to define the average daily high and low temperature for your landfill. Again, this information will be referred to later in the audit-particularly as it relates to equipment hauling (or pushing) uphill in the summer.

Finally, average wind speed can be used for litter control. For example, to minimize litter, the landfill may plan to fill-in sheltered areas during the periods of higher wind. This information can also be used to correlate wind to litter crew costs.

Incoming Waste

The monthly tonnage for your site can be used to project (or compare) seasonal variations in operating cost, compaction, cover-soil use, and so on. These data should be put into a table or graph.

Another useful bit of information is tons received per hour. If your landfill is using a computerized weighing system, the scale operator should be able to provide this type of a report. If your system is not computerized or if you do not record the time that customers enter your landfill, then you might have to prepare a form and have someone record these data. To ensure accuracy, it’s a good idea to record at least a week’s worth of times.

This information will form the basis for many of the analyses that will be performed later on in the audit. These include dozer productivity and appropriate push distances, compactor productivity and optimum density, cover-soil and ADC placement, employee scheduling, sizing the tipping pad, and optimum cell geometry.

If possible, obtain information on how many cubic yards of waste (that’s loose cubic yards) come into the landfill daily and hour by hour. Cubic yards per hour is used to help measure the dozer’s productivity and for sizing the tipping pad and employee scheduling. If you have detailed records for the weight and type of each load coming into the landfill each hour, it’s a simple matter of converting weight to yards based on the density of various types of garbage.

For example, suppose that during a one-hour period, 40 tons of the waste received came in packer trucks. By multiplying the weight of waste by the approximate density, you can estimate how many cubic yards of waste were brought in. Waste dumped from a packer truck may have a density of 500 lb./yd.3 Dividing 80,000 lb. (40 tons x 2,000 lb.) by 500 lb./yd.3 equals 160 yd.3 Do the same for the other types of waste, using the appropriate density factor, then add them together to get an hourly total in cubic yards.

Equipment Hours

Performing a landfill operations audit would be difficult without having some information on equipment hours. If possible, it’s best to have equipment hours for all major pieces of equipment broken down into average hours per day. Obtain this information for each month for each machine. There are many other types of information that can be useful for performing a landfill-operations audit. However, these three-weather, tonnage, and equipment-are foundational. In future articles, we’ll discuss ways to use these simple data as you audit your landfill.