In a world that increasingly demands our natural resources be protected, there’s a lot to be said for asphalt’s nearly 100% recyclability. The life cycle of pavement creates a neat circle, beginning with crushed stone mixed with liquid asphalt and then spread along our roadways, driveways, paths and other surfaces throughout the country. When its usefulness in those places is complete, it is simply gathered and crushed, and the cycle begins again.
However, asphalt also plays a big, but lesser known, role in the conservation and treatment of water. It may seem counterintuitive that an essentially stone and petroleum-based product would be so instrumental in preserving and protecting our greatest resource, but the impervious properties are exactly right for many applications.
When you order fish for dinner you may not immediately think of asphalt. Who would? But fish hatcheries have used asphalt to their advantage for several decades. As it turns out, those little fish babies are quite susceptible to chemicals and contamination. When their water-filled playpen is lined with asphalt, those toxins can’t seep through, and the fish grow and thrive in their fresh, clean environment.
On the other side of the spectrum, industrial plants use asphalt-lined retention ponds to keep pollutants and hazardous waste IN until it can be mitigated. The strong, watertight surface of the asphalt effectively keeps contaminates out of the soil and groundwater and can also be used to cap hazardous waste.
These days, plastic and soil liners—once standard in landfills—are increasingly replaced with asphalt liners. The benefits of this switch are quite impactful. For starters, when asphalt is applied and layered with a geosynthetic fabric, it can reduce the amount of liquid making its way through the plastic and soil barrier. Former liners allowed around 140 gallons of toxic gunk per acre per day to escape. Asphalt has brought that leakage to a nearly immeasurable amount. Additionally, the longevity of asphalt liners is over 300 years longer (asphalt liners last more than 1,000 years whereas plastic/soil liners only last around 700 years).
Drinking water also benefits from the applications of asphalt. The Metropolitan District of Southern California has been using asphalt lined reservoirs for over 40 years. Asphalt makes reservoirs and dams cost effective, practical, and long lasting.
The world of asphalt is constantly evolving and changing to meet the needs of society and do it in a responsible manner. We are happy to be a part of this bigger whole and look forward to new advances in our industry that we can continue to bring to you, our customers!