Ketchikan’s source of drinking water might have too much bacteria, and that could mean expensive upgrades for the city’s water department. And mountain goats and climate change might be to blame.

Ketchikan’s drinking water supply isn’t filtered. It’s simply pumped from reservoirs as so-called “raw water”, disinfected with chlorine and ultraviolet light and sent into the public water system.

It’s normal to see low levels of bacteria in the untreated raw water, especially fecal coliform — the kind that can make people sick. After all, humans aren’t the only ones drinking from Ketchikan’s reservoirs.

“Bear, geese, deer, mountain goats, and, you know, being mammals, there’s a certain amount of excrement,” John Kleinegger said. He’s Ketchikan Public Utilities’ water manager.

Usually, it’s not a problem.

But for Ketchikan to keep its low-cost, low-maintenance approach to drinking water, Ketchikan Public Utilities, or KPU, has to prove the raw water — that is, before it’s disinfected — is relatively clean. State regulators set the limit for that.

Right now, Ketchikan looks like it might go over that limit. Recent samples from the city’s reservoirs have come back high.

Assistant City Manager Lacey Simpson updated Ketchikan’s city council at a recent meeting.

“I wanted to report to the council that unfortunately, we have exceeded yet again our raw water sample that was taken the other week. We just got the results today,” Simpson said.

She told the council that if the next sample is over the limit, the utility could be in violation of state water regulations.

This is a new problem for the city. So, where’s it coming from?

Kleinegger points to a couple of possible causes.

“One of which, mountain goats have been introduced into the area. And, quite frankly, they’re thriving,” Kleinegger said.

The Alaska Department of Fish and Game first introduced mountain goats to Ketchikan about 35 years ago, and wildlife officials say the population is healthy and growing. They also say the goats like to hang out on steep hillsides, just like those above some of Ketchikan’s reservoirs.

Kleinegger says that while animals like bears, wolves and mice have long frequented the city’s reservoirs, the booming population of mountain goats could be the culprit.

Kleinegger says another possible cause is climate change.

“Well, warmer conditions, you know, allows the fecal colonies to grow under higher temperatures, which are conducive to growth,” he said.

On top of that, Ketchikan’s ongoing drought means more sunshine and higher temperatures. Then, when it rains, those bacterial colonies flow down the hill and into Ketchikan’s reservoirs.

But if KPU keeps seeing high levels of fecal coliform in its raw water supply, it could lose its right to remain unfiltered — it might be forced to build a filtration plant. And that’s expensive.

“About $70 million and about another $2 million a year to operate,” Kleinegger said.

Kleinegger says the entire water division’s currently spends between $3.5 and $4 million per year. That means a filtration plant would cost more than half the current budget — just to operate. Construction costs would almost triple KPU’s current debt level, according to the utility’s 2019 budget.

Kleinegger says KPU has a limited number of tools to keep those numbers down. For example, to avoid spikes in bacteria levels after a rainstorm, the utility can switch to a lower-bacteria water source. But that’s not always possible — KPU’s electric division often needs that same water to generate electricity.

This story was produced as part of a collaboration between KRBD and Alaska’s Energy Desk.