Quantifying the quality and sampling time of oil and grease in urban stormwater runoff

• Published in: KSCE journal of civil engineering 2017, 21(4), , pp.1087-1095
• Main Authors: Chow, M. F., Yusop, Z.
• Format: Article
• Language: English
• Subjects: Ammonia; Catchment area; Catchments; Civil Engineering; Correlation analysis; Engineering; Environmental Engineering; Flow measurement; Geotechnical Engineering & Applied Earth Sciences; Grease; Greases; Industrial Pollution Prevention; Land use; Oil pollution; Pollution; Quality assessment; Rainfall; Runoff; Sampling; Sampling methods; Storm runoff; Storms; Stormwater; Stormwater management; Stormwater runoff; Urban runoff; 토목공학
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-016-0304-0

Oil and Grease (O&G) pollution in urban stormwater runoff is an important issue especially for tropical country with high intense and frequent storms. Monitoring of O&G pollution is comparably more difficult than other conventional constituents due to the requirement of manual grab sampling technique. Thus, this paper was aimed to investigate the O&G quality and quantify an appropriate sampling time for collecting sample that approximating Event Mean Concentration (EMC) of O&G (EMC O&G ) from residential, commercial and industrial catchments. An average of 16 storm events was collected from each land use in order to assess the quality of O&G in stormwater runoff. A series of stormwater samples were manually grabbed by sampling personnel along with the storm flow measurements. Results showed that industrial catchment always exhibited the highest EMC O&G value, followed by commercial and residential catchments. Correlation analysis indicated that EMC O&G was correlated well with EMCs of NO 3 -N, NH 3 -N, TP and SP in the commercial catchment. The EMC O&G was also found to be independent of all storm characteristics, except for storm duration in the industrial catchment. Results obtained from this study suggested that the mean sampling times for collecting EMC O&G sample (TEMC O&G ) at residential, commercial and industrial catchments are 17, 17 and 20 minutes, respectively. The TEMC O&G had mostly preceded the peak flow by a time-based ratio of 0.70. Thus, this best time sampling strategy can be implemented based on forecasting rainfall and estimated time to peak flow at catchment outlet.