The first thing to understand is that this sewer proposal is not the projected large line running east to the area of the future site of PhoenixMart. This concerns the lines down Kortsen Road and how that system is nearing capacity.
The only way PhoenixMart ties in to the sewer is if nothing is done about Kortsen, because the future flow coming from PhoenixMart and linking to Kortsen will cause major problems.
That’s why, perhaps belatedly, the city is paying an engineering company $499,700 to figure out what would be the best alignment for one of the three reliever line routes studied.
“Currently, the existing sewer lines within Kortsen serve approximately half of the city’s wastewater service area,” Deputy Public Works Director Terry McKeon told the council. “The capacity available in those lines, it’s getting close to full, is the simple way to put it. We need to put together a plan for providing relief for those sewers to be able to continue to serve and develop within the area.”
The evaluation by Sunrise Engineering will determine which of three corridors would be best for a replacement sewer.
McKeon asked, “Where here can we get the most bang for our buck? What can we afford to build that provides us the most capacity we can afford without having a ridiculously large sewer?”
McKeon said the city has worked with Sunrise to do that evaluation and provide a conceptual design.
“Not full design plans,” he added, “but conceptual vertical and horizontal alignment to identify constraints, challenges and, most importantly, cost estimating. At the end of the day we need a reliable cost estimate that we can then carry forward and budget and be able to find the money and build it.”
Councilman Matt Herman, calling the project “very unglamorous, but very necessary,” asked how long it might be before the Kortsen system is full.
“I know it is a bit of a moving target, but what are you anticipating?” he asked. “Are we going to have to be ready for this next year or in five years?”
McKeon replied, “Unfortunately, we haven’t budgeted crystal balls yet. A lot of it, really, obviously all depends on development. When this project was conceptualized, if you will, or put into the budget process, we were in the process of determining the needs for the PhoenixMart development and adjacent area.”
He continued, “The short answer is essentially when and if the first phase of PhoenixMart is built, that is probably going to take up every drop we have available in the existing system. So in some ways, we might be a little bit behind the ball on this one, but we need to get this project ready to roll forward and make it shovel-ready for whenever that time comes.”
Herman said he wanted to make clear that this is not the PhoenixMart sewer line project itself.
“No, it is not,” McKeon replied. “This is not just to accommodate PhoenixMart. It would be almost as complicated as this, but it would be kind of pointless. We’re looking for much more than that – to be able to support much more future development than simply PhoenixMart or even the east area.”
Councilwoman Lisa Fitzgibbons asked if it is common that sewer lines need to be expanded, adding, “How are we here?”
McKeon said, “Well, I think the nature of development is you can master plan. We have a number of master plans (and) we’ve had many over the years that show you ultimately this is what you need. But you’re a small community, you can’t afford a 60-inch diameter, 12-mile-long sewer that’s going to sit there for 40, 50 years, so you develop interim solutions, sizing that fits the need.”
City Manager Jim Thompson said that about 10 years ago, before the TransWestern gas line came through the community, the city talked about putting a sewer line along the north branch of the Santa Cruz to help service the area, plus talked about going to Rodeo Road to catch everything from the north.
“Eventually, they all ended up on Kortsen, because that’s where the (treatment) plant is located,” Thompson continued.
That plant would eventually handle 50 million gallons of sewage a day, Thompson said, noting the city has acquired additional land for expansion.
“We know eventually Kortsen’s going to have to service a lot or we have to come from different directions,” he continued. “We’ve looked at different alternatives but we’ve never sat down and done a master plan to really give us all the numbers and all the information. We’ve talked about alternative lines; we’ve talked about picking some additional up south of it down on Casa Grande Avenue and other locations and bringing it closer to the plant, then putting it back into Kortsen, but we’ve never sat down and talked about the final portion on this side of the interstate.”
On the east side of Interstate 10, Thompson said, “We’ve designed the entire system through the master plan and then in relationship with our partnership with PhoenixMart where they’re going to pay for that portion of the engineering, which they have done. But on this west side we know that we needed some additional alternatives.”
He continued, “So I think right now the biggest issue for us over the history of it is to find out what of those alternatives is the best.”
A major challenge for upsizing the Kortsen lines, Thompson said, “is that Kortsen is so heavily used and we have multiple schools now located off that roadway and when you put a major sewer line into Kortsen you start tearing up the road. That’s why we looked at the north branch of the Santa Cruz back then, but that was somewhat inefficient and then when TransWestern came in and took some of that area that we would have otherwise used, we talked about concerns over if we do have a large (flood) event how much of the soil is going to be scoured away, will it expose pipes? There are other concerns. So then we started talking about Rodeo. We pick up almost everything from the north if we put a larger lateral down Rodeo and then drop into the plant that way, as well.”
He added, “That’s where we kind of gravitated towards over the years, but now we want to really know what’s the best alternative (and) what the costs are associated with that. But we have been talking about it for 10 years, so it isn’t something that we’ve ignored, it’s just a matter of this is a sewer project, so whenever we go to spend money it impacts rates. And we know our concerns over the rates over the years, we’ve tried (to be) as frugal as we can, and as Terry’s mentioned we found other ways to divert flows, to do other things, but now we’re to the point that we need to start doing something and move the project forward, so that’s why we’re here this evening.”
Mayor Bob Jackson said the situation is similar to the southwest area of the city, where the Burris Road sewer line was upgraded to handle more flow from the industrial area.
Councilwoman Mary Kortsen said, “I like the timing on this because my concern has been that we have that Kortsen interchange (on I-10) coming up, we’re trying to encourage Arizona Department of Transportation to come in and expand and add those lanes in there. I’d like to have this in place and done before they come in to do it because I think it’s going to be cheaper than them putting everything in and then us trying to dig under. So the timing, I believe, is just critical in that area in addition to capacity.”
McKeon replied, “Just to note, as Jim mentioned, the city’s east area sewer expansion project, which is currently under design and that PhoenixMart is actually paying for, goes from the west side of I-10 all the way over toward PhoenixMart. That project actually accommodates the footprint of that overpass.”