009S22 - Faro Mine Remediation Project - Descaling of X13 Pipeline

In 2018, a sump-based, open air outdoor collection and pumping system was designed and constructed in the Downvalley area of the Faro side of Site. This pumping system was named X13, after the environmental sampling identification number of the surface water sampling station nearby. The system is connected to an 850m long 12” diameter HDPE DR17 pipeline, which routes the water from the collection sump into a reservoir at a higher elevation (the Cross Valley Pond or CVP). In the years since the system was commissioned, it has been in almost constant operation (with the exception of power outages and regular maintenance). In the previous year, a pointed reduction in flow has been noted in the system. Upon investigation, the operations team at site has noted a buildup of scale on the inside of the pipe. This scale has been observed to be 1-2” in depth, and composed of Fe, Mg, and Zn. The desired services that Parsons requires is a descaling of the pipeline, returning it to unrestricted flow (original condition of operation). For Scope of Work, see the Sample Subcontract (beginning on page 19).