An Audit report published by Washington State urges Seattle's Sound Transit to better do their homework to avoid change requests later causing additional costs as much as 8% over the project costs.

The report titled 'Improving Sound Transit’s Project Planning and Design to Reduce Costs' writes that only the single cause of unexpected underground conditions constitute 46% of the total change requests resulting in Sound Transit spent more than $79 million to address them. According to the report, this single cause has occurred in every project reviewed, saying:

"In one example, contractors found large amounts of contaminated soil during construction on the D to M Street project, one section of Sound Transit’s commuter rail line. Sound Transit said it chose not to investigate underground conditions in certain areas because it would have had to drill on high-traffic streets. Such drilling is disruptive to the public: the agency must close down public streets, hire traffic control crews, drill through existing asphalt or concrete, and repair the road afterwards. However, the cost of dealing with unexpected contaminated soil proved to be even more expensive. The contractor’s original bid on this project included soil removal at $12 per ton. When 466,000 more tons of contaminated soil was found than expected – nine times what Sound Transit estimated – the contractor submitted a change order charging $28.80 per ton, more than twice the rate in the original bid. Sound Transit spent more than $13 million to remove contaminated soil that was not discovered as part of its investigation. Change orders for this issue alone accounted for 20 percent of the total contract.

In another example, Sound Transit did not have an adequate understanding of the volume of groundwater at a construction site. On the Northgate Link light rail extension, Sound Transit identified groundwater during exploration of the area planned for tunnels. Sound Transit originally planned to spend around $375,000 to mitigate this issue but the contractor found far more water than expected. As a result, Sound Transit issued around 40 change orders for testing, wells to capture and remove groundwater, and additional equipment needed to address the problem. In the end, Sound Transit paid more than $50 million to deal with this issue – 10 percent of the total contract. Sound Transit is seeking to recover some of these costs from the design consultant in court."

Report says, more underground exploration could have uncovered these issues and saved Sound Transit money.

In a letter to the auditors, Sound Transit CEO Peter M. Rogoff responded that "even before Sound Transit expands its success through our execution of [report's] recommendations, our change orders already fall within industry standards, especially given the complexity of some of our work, such as tunneling."

If you would like to read the full audit report:

https://www.sao.wa.gov/wp-content/uploads/Tabs/PerformanceAudit/PA_Improving_Sound_Transit_Project_Planning_Reduce_Costs_ar1026355.pdf