The Contribution of Water and Sewage Tankers to Traffic Noise in an Urban Environment with Incomplete Municipal Water and Sewer Networks

Noise level from traffic activities is affected by many factors, of which traffic density and composition are crucial. For instance, passenger cars and heavy trucks emit noise with different levels and spectra. In Jeddah City, Saudi Arabia, the municipal water and sewer networks are incomplete. For this, many urban districts depend on water supply by water tankers while disposing off sewage by sewage tankers. This makes the number of such type of truck is high on roads. Since the noise generated from these tankers is expected to affect the urban noise in Jeddah, the objective of this research is to determine tankers’ contribution to urban traffic noise in two districts. The data required for prediction of traffic noise were collected and/or calculated and then processed using Predictor-LimA software using the CNOSSOS-EU method for road traffic noise. Noise maps during day, evening, night and 24-h average for all traffic forms, for tankers-free traffic, and for tankers only were generated. It was found that the water and sewage tankers increased the average traffic noise levels by values in the range 0–2.3 dB (Mean: 0.9 dB; S.D.: ± 0.7), depending on the closeness of the area of interest to the entry/exit routes of the tankers to/from the districts. Until the time to cover all the city by the sewerage system, traffic rules for the tanker may be enforced including time of routing and entry routes in a way that distributes the increase of noise level uniformly over the districts.