'Worst work in the world': US park rangers grapple with tide of human waste

With toilets in short supply, ordure can harm streams and wildlife. An entrepreneur has a nifty solution

For 20 years, Richard Lechleitner had a grueling task at Mt Rainier national park: digging human waste out of backcountry toilets and carrying it down the mountains.

Staff at the park in Washington state grappled with an influx of visitors hiking far from roads, along with thousands of climbers attempting to reach the active volcano's 14,000ft summit each year. People heeded the call of nature on Mt Rainier's pristine glaciers, as well as in its unvarnished wilderness toilets.