Sakhalin Energy appointed a total of 5 external observers, 4 of them dedicated full time to the field work in the spreads, and one stationed in Yuzhno-Sakhalinsk responsible for QA / QC of the reports. 17 Russian observers from Haskoning Sakhalin observers were paired with the external observers, they presented during the construction at all sensitive crossings (Group 2 and 3 rivers and critical tributaries). They notified of any observed non-compliances in the River Crossing Monitoring Checklist. In addition, they assessed the actual impact of those non-compliances, in line with the HSESAP methodology. At the end of the winter season Haskoning Sakhalin observers helped to prepare a final and public report.

Haskoning Sakhalin observers team included biologists (they were responsible for water and sediments sampling, impact assessment and took measures on decreasing a negative impact on salmon population) and hydrologists (they were responsible for water sampling and water quality testing, water flow measuring, assessment of construction works impact on water quality and hydrology). All observers had skills in using field equipment/methodologies, including GPS, flow meter, turbidimeter, as well as skills in total suspended substances quantity sampling.