Effects of Road Oils and Tars on Public Water Supplies

Abstract

In a previous article (1) it has been found that the drainage from tarred roads produced objectionable tastes and odors in water supplies after chlorination. Sample sections of road were treated with varying amounts of primer and retread tar and the section of road washed by distilled water equivalent to 1-inch of rainfall per hour. These washings were tested for tastes, phenols, and mixed cresols. The tests showed that the greatest danger of contamination of water supplies was when a rain occurred within four hours after the application of the primer coat. If a local heavy rain occurred in the vicinity of the road oiling job, there was danger of contamination of surface water supplies. One hour after the application of the primer coat, tastes were noticeable in a 1 : 2,000,000 dilution. Data seemed to be lacking on the water soluble compounds of the road paving tars and this paper offers the results of tests made on this subject by the Department of Civil Engineering, West Virginia University, Testing Division of the State Road Commission, and the State Water Commission. The laboratory work was performed by the junior authors. The purpose of these tests was to investigate the following : 1. The danger of contamination of water supplies from the washings from asphalt roads. 2. To express in terms of a phenol equivalent, the percentage of water soluble, chlorine absorbing compounds present in road tars.