Department of Engineering & Public Works
TO: Amelia McCulley, Director of Building Code and Zoning Services
Wayne Cilimberg, Director of Planning and Comprehensive Development
Michael Barnes, Planning and Community Development
FROM: Mark B. Graham, Director of Engineering and Public Works
DATE: 14May 2002
RE: Fill and Waste Zoning Text Amendment
Inclusion of Asphalt Based Pavements in allowed fill
I am offering this as Engineering's recommendation that asphalt pavement be considered an acceptable fill material under Section 5.1.28 of the Zoning Ordinance. This recommendation is based on 3 factors: 1) environmental and health risks, 2) consequences of the alternatives, and 3) economics.
1. Environmental and Health Risks
After a thorough search of the available information, I have found no conclusive evidence that there is any harm in burying this material. I have found a number of situations that show asphalt concrete is considered safe. Perhaps the best example of this safety is asphalt pavement is currently being used to line water reservoirs in California and this use is being planned for future reservoirs. This is a situation where the asphalt pavement is in direct contract to water being used for consumption. Similarly, both the U.S. Environmental Protection Agency and the Virginia Department of Environmental Quality material find it acceptable to bury asphalt pavement without regulation, while materials that we might consider somewhat benign (e.g. tree stumps) are regulated wastes.
I appreciate the concern the Planning Commission expressed that nobody has proven this material is absolutely safe to bury. I seriously doubt that anyone ever will be able to conclusively prove this material is safe, but that appears to be caused by the difficulty of such a scientific proof rather than any observed risk. To explain this, I would consider the similarities between asphalt pavement and peanut butter with regard to risks. Both substances contain chemical compounds that are suspected health risks. Both substances have been extensively tested for risks, but neither substance has been proven to be a risk. Despite this testing, both substances continue to have their long-term safety questioned because of concerns with some of the chemicals in the substance.
Finally, I believe we need to ask ourselves why asphalt pavement is considered an unacceptable risk in fill but we plan to continue using it on roads. When used on roads, this asphalt pavement is directly exposed to rain that will wash any residues into nearby streams and rivers. If the same asphalt pavement is buried, the time required for groundwater to flow from this material to a point where there is exposure, such as wells or reservoirs, will be orders of magnitude longer than what happens with existing roads. For buried asphalt pavement, that means there is considerably more time for biodegradation of any harmful compounds. Even if it were eventually proven that asphalt pavement has harmful compounds in the residue leaching from it, which appears highly unlikely, the risk associated with the buried pavement would be insignificant compared to what is happening right now with the existing roads.
2. Consequences of the Alternatives
If asphalt pavement cannot be used as fill in the County, we should consider what will happen to that material when it is taken from a demolition site. The obvious answer is the contractor will need to separate the materials at the demolition site from materials that can be handled in another way. Potentially, we could have three separate types of loads leaving a site; fill material (including concrete but not asphalt), regulated construction debris that goes to a landfill (e.g. wallboard, wiring, metal), and asphalt pavement. I believe there are five disposal options for the asphalt pavement that need to be discussed.
1) The contractor will mix this asphalt pavement with regulated construction debris that will be taken to the County designated waste transfer station for disposal in a regulated landfill. That could answer the questions as to a safer method of disposal, but I don't expect this option will be used. As it will cost the contractor $46 per ton to dump this material at the waste transfer site and much cheaper means of disposal exist, I expect few contractors will ever use this option.
2) The contractor will take the asphalt pavement to the Ivy landfill where they will pay $8 per ton for disposal as clean fill. It is important to note this material will not be buried in a regulated landfill cell but it will be used as fill material on the site outside of a controlled landfill cell. From an environmental perspective, the disposal of the material at the landfill would be no different than the contractor using it on a site that needs fill. The only difference being this is allowed at Ivy because that disposal is regulated by DEQ while the County regulates the disposal at other locations under the Zoning Ordinance.
3) The contractor will haul this to an adjoining locality where it is legal and routinely used as fill. That happens now and I expect this practice would continue.
4) The contractor will illegally dump this material in the County. That happens now and I expect this practice would continue. A circumstance we have noted in the past is for the contractor to make an arrangement with a landowner to fill in some gullies on a property in the rural area. That provides the contractor a cheap way of disposing of this material and provides the landowner some remediation of erosion occurring on their property, albeit, an illegal one.
5) The fifth option is the asphalt pavement could be recycled. That recycling would either mix the old pavement material with new asphalt pavement or would simply crush it for use as base material in parking lots and driveways. While we strongly encourage the recycling of this material, it remains debatable whether some private business will find this a profitable enterprise. There are also County complexities to such an enterprise. While the zoning classification of such an enterprise could depend on the other uses on the property, it appears this enterprise would probably require a Special Use Permit before it could be done in the County. All in all, while I would like to see us encourage recycling of this material, I don't feel we can reply on there being a demand for this product anytime in the near future.
Of these five options, I believe the first will almost never be used due to the cost. Of the next three options, the asphalt pavement will be used as fill in an identical manner as it would if permitted by the Zoning Ordinance. Thus, whatever risk might exist is unchanged. The fifth option, while it would solve a number of problems, appears to have an uncertain future.
There is one more potential consequence that should be discussed. In considering sites that require fill material, every ton of fill that is created using demolished asphalt pavement is equal to one less ton of dirt that comes from a borrow area. It is important to recognize that the only permitted borrow sites are in the rural area. While I won't claim that this amount of fill would make an appreciable difference in the number or size of these borrow areas, it is focusing on the idea that we want to minimize this type of disturbance in the rural area.
I believe the above two factors demonstrate there is no real benefit to prohibiting the use of asphalt pavement as fill material. The remaining consideration is whether treating asphalt pavement differently creates an economic disadvantage. In my opinion, this is clearly an economic disadvantage. If a contractor is required to take expend extra time, equipment and money to handle these materials, there is little question this will be reflected in the ultimate cost of development in the County. Similarly, if the County staff must verify how the contractor is handling this separate material and spend more time on enforcement of illegal waste areas, the cost to the County for enforcement has also increased. Thus, I believe there are real costs to both the County and the community at large in requiring asphalt pavement to be treated differently than other materials, without a demonstrated benefit.
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