On-Site Remediation Project for Long-Distance Pipeline in Miaoli

Site Background

The remediation site is located at the 129-km marker of Provincial Highway 1, where CPC Corporation’s long-distance oil pipeline is buried beneath the road. During planned pipeline upgrades that required crossing a drainage ditch, the pipeline was installed at a depth of 4.5 m. However, an accidental breach of the pipeline by a steel pile resulted in significant oil leakage, which spread along the drainage channel downstream, contaminating the road, drainage channel, and downstream farmland. The site’s topography posed additional challenges, with a 4.5-meter elevation difference between the roadway and drainage channels, which expedited the spread of oil pollution.

Pollution Status

In 2009, Miaoli County's Environmental Protection Bureau mandated remediation for this site per Article 8 of the Soil and Groundwater Pollution Remediation Act. In 2011, the site was designated as a soil and groundwater pollution control site due to contaminants, including TPH* in soil, and benzene and naphthalene  in groundwater. Initial estimates indicated a 1,700 m² pollution area; however, further assessment identified an approximate soil pollution area of 950 m² and a groundwater contamination area of around 9,000 m². Remediation complexities were heightened by the site’s uneven terrain, with elevation changes reaching up to 4.5 m, and pollution extending across the highway and underlying drainage channel.

Remediation Approach

Provincial Highway 1 is a major thoroughfare with numerous subsurface utilities, including long-distance oil pipelines, a 12-inch gas pipeline, water lines, and telecommunications cables. Due to restrictions on road closures, ApolloTech installed remediation wells along the sides of the road and within the central median for onsite bioremediation.

Launched at the end of 2012, the remediation program was successfully completed in approximately three years. Miaoli County Government confirmed successful remediation in early 2014, leading to the site’s removal from the controlled site list.

Note: *Total Petroleum Hydrocarbons (TPH)