A 2018 case study (C2018-10909) required a rapid quantitative assessment of the external corrosion
rate (CR) that buried station piping was subject to when equipped with an underperforming Cathodic
Protection (CP) system in a high electrolyte resistivity environment. Originally installed multi-function
instrumented probes provided initial operating data indicating acceptable CRs despite sub-criterion and
speculative CP data. Operating this monitoring system in a multifaceted electrolyte, with confounding
electrolyte variables, warranted further investigation when intriguing data was recorded.
This follow-up case study presents findings post installation and operation of a revised soil side electrical
resistance (ER) probe and coupon monitoring system following originally installed 100 μm probe failures.
Utilizing monitoring hardware from multiple manufacturers and datasets beyond CP helped to shed light
on the real driver of the original accelerated probe failures. Soil composition at pipe burial depth,
installation practices, ER probe data, and CP data all combined to facilitate assessment of the corrosion
mechanism through a wider lens.