Highlights from an interview with Brett Jokela, General Manager, Anchorage Water and Wastewater Utility (AWWU)
Q: What are some challenges you face due to your unique climate?
A: Cold is obviously a challenge. Frost can penetrate deep into the ground over the course of a long winter. We go to a depth of at least 10 feet to bury pipes versus the three to four feet depth common in many communities in the Lower 48. That greater depth leads to higher construction, replacement and repair costs. Our break rate is probably lower per 100 miles of pipe than more southern communities, but when a pipe breaks, it’s a big deal. It takes a lot more equipment and time to repair, but our crews are great. To break through frost they have to use special technology where they drive steam into the ground to thaw the ground, then excavate to repair the pipe. The frozen ground also affects the prognosis of pipe breaks. There could be a break at Point A, but because of frozen soil the leaking water may not show at the surface at that location. The water travels further down the pipe and the leak shows up at Point B. Our crews dig at Point B only to find out that the break is actually somewhere else. Also, because of the depth of the frost, thawing makes the ground move and we see more pipe breaks in the late winter and early spring.
Q: Is climate change impacting your ability to provide clean drinking water to your customers? What is AWWU doing to address climate change?
A: We are actually less impacted by climate change than many of our peers, like communities facing highly variable rainfall, as in California. Ninety percent of our water comes from Eklutna Lake, which is dominated by runoff from a glaciated mountain watershed. We worked with glaciologists from Alaska Pacific University because of our concerns regarding climate change. Their studies indicate that although the glacier is receding, runoff from the glacier and other portions of the watershed will provide a secure source of water for a long time to come. Separat
ely, we saw an opportunity to decrease our power needs plus convert to renewable energy. Back in the 1980’s all the water in Eklutna Lake was dedicated to hydroelectric power production. We negotiated with the federal agency running the power plant to take some water directly from the lake, instead of pumping water from the hydropower tailrace at sea level. We realized we could use the elevation of the lake to provide water to our customers without pumping. Today, only a small fraction of our distribution network at higher elevations, less than 10%, depends on pumping for water delivery. The Utility also uses the flow from the lake to our water treatment plant to generate electricity for our own use. It’s enough to cover all our water plant power needs and put power back in the grid. The cost savings really help us appreciate renewable energy.
A: We are very active working with industry groups. While we are new to Global Water Intelligence (GWI), we have been a member of American Water Works Association (AWWA), the Association of Metropolitan Water Agencies (AMWA), the Water Environment Federation (WEF), and the National Association of Clean Water Agencies (NACWA) for decades. We think connections with professional groups at both the executive and staff levels are very important. About 20% of our staff travels outside of Alaska to attend training opportunities and industry workshops each year.
Q: Is there an innovative solution AWWU devised that you are particularly proud of?
A: We partnered with our sister utility, Municipal Light & Power, to share cooling systems in a new co-generation plant. In the multi-stage process, power is generated first from combustion of natural gas and then from steam created by the heat of the natural gas turbines. The water is then condensed using cooling towers, and the last bit of heat from warm cooling water is transferred to potable water destined for AWWU customers through our distribution system. This novel approach warms the water going through AWWU’s pipes to 55 to 60 degrees Fahrenheit versus the typical source water temperature of 45 degrees. Warmer water in the pipes reduces the likelihood of breaks because the occurrence of frozen soil around the buried pipe is less likely. But the best advantage is to our customers throughout the city. They can now use less fossil fuel to heat the water in their homes since it is coming in 10 to 15 degrees warmer than in the past.