FLAGSTAFF, Ariz. (AP) — People who hike to the bottom of the Grand Canyon will have less options for overnight stays and for restrooms because of strains on a wastewater treatment plant.

The plant at Phantom Ranch needs an overhaul because it doesn't meet current state requirements for effluent, park officials said Tuesday.

As a result, the hiker dormitories and guest showers will be closed through at least 2021. Individual rustic cabins at Phantom Ranch that are reserved through an online lottery and the canteen will stay open.

Reservations at Bright Angel Campground also will be cut in half and the use of flushing toilets limited. Visitors are encouraged to use a handful of composting and pit toilets along each of the three most popular hiking trails.

Xanterra, which operates Phantom Ranch and the campground, said it will refund customers who had reservations.

Melissa Verlet and her family had reservations for the hiker dormitories in November. Her 9-year-old daughter was looking forward to earning a special junior ranger award that’s given only to hikers who make it to Phantom Ranch.

Verlet said she isn’t sure her family will have the flexibility in the future to try and book the trip again.

“It’s definitely worth the experience if you’re prepared to go," the Littleton, Colorado, resident said Wednesday. "It's worth the hassle with the lottery, and it’s worth the cost, just not in the summer.”

The overhaul of the treatment plant is expected to take 18 months to two years to complete and cost around $3 million, the park said.

The plant was built in the 1980s to serve Phantom Ranch, the campground and about 15 day-use visitors. Before the coronavirus pandemic, several hundred people a day would either hike to the Colorado River or run between the north and south rims, taxing the system, said Brenna White, a civil engineer at the park.

The overhaul won't increase the capacity of the wastewater treatment plant, but it will be more efficient, White said.

“It's more of an optimization of what's there to get the most out of it and to come back under a modern permit,” she said.