In fact, I’m proud to say that for the second time in the last three years, Northwest Natural posted the highest score in the nation in the JD Power gas utility residential customer satisfaction survey. Earlier this year, Northwest Natural also received top honors from business customers, ranking highest in the West region in the JD Power business customer satisfaction survey. These are accomplishments that our employees work very hard to achieve and ones we don't take for granted.
Before I turn it over to David, I wanted to touch on two other topics. First, let me talk about Northwest Natural's pipeline safety program in light of the recent San Bruno tragedy. As you may recall in 2004 the Oregon PUC and our customer advocates approved a rate treatment and cost recovery for Northwest Natural's pipeline integrity program.
This program allows us to spend $12 million per year on pipeline and other system integrity work with approximately $9 million rolling into rates each November. In our view this kind of proactive rate treatment for pipeline integrity management should be a model for the industry, and we believe Oregon regulators and our customer advocates deserve a lot of credit for it.
In fact, with support from our regulators and customer groups, we believe we have one of the most modern pipeline systems in the country. For example, we were one of the first gas utilities in the nation to replace all of our cast iron pipes and we have aggressively replaced all of the bare steel on the transmission system and we have only 34 miles left in our distribution system.And we are on target to replace what is left prior to the 2021 scheduled date. As we monitor the pipeline safety legislation currently being considered in Washington DC, we will also be meeting with regulators in both states, about what the potential changes in federal law could mean for extending or expanding our system integrity program. Read the rest of this transcript for free on seekingalpha.com