Harold Nagato's job stinks and he loves it.

Nagato is the president of Environmental Waste Management Systems Inc. and developer of a septic tank system that safely discharges treated wastewater into the ground. The 61-year-old former insurance salesman designed the system after turning to a career as a contractor and realizing there were many communities in Hawai'i that lacked a central sewage system.

It took Nagato more than two years and thousands of dollars to develop his Environmental Sewage-treatment Innovative System, or ESIS. The process required months of trial and error before it passed strict Environmental Protection Agency and Department of Health regulations.

Although he had government approval and his septic tank invention was cleaner than many other systems, business started off very slowly. Nagato sold just 120 systems in the first 10 years, which he called the "onesie, twosie" period when he was lucky to install more than one a month.

But with rising sewer fees and an EPA ban on large-capacity cess pools, sales in the past two years have taken off. His company already has orders for 200 systems in the next year and the systems cost from $25,000 to $30,000.

In addition to Hawai'i, Environmental Waste Management Systems has jobs in Guam and Samoa, and Nagato does consulting work in Asia. He also formed a spinoff company that does the maintenance work on the systems.

Nagato was recognized last year by the Better Business Bureau with a Torch Award for ethics in business. His company also was named a 2007 Top High Tech Leader by the Pacific Technology Foundation.

Despite the accolades, there's no sugar-coating what the business is all about, and Nagato said that's why it's become so successful.

"If they ever discover a pill that you and I can take and we don't have to go to the bathroom, then I'm out of business. Until then, keep eating, keep using the bathroom, and you make me happy," Nagato said with a chuckle. "I don't see a rush of people saying 'Let me be a wastewater guy.' Our business takes a certain amount of gumption. Most people can't deal with it, but somebody has to do it."

Sewage was not an industry that Nagato considered as a young adult. He sold insurance for 20 years, but also helped an uncle with his contracting business and found that people were more willing to spend money on their home than on life insurance.

In 1981 he started his own contracting company, Area Builders, and while developing a project on the Big Island in the early 1990s he discovered that many places were not hooked up to a sewage system. Nagato then set out to design his own septic system, despite many people telling him that there was no future in this business.

Nagato isn't an engineer and he spent years doing research on other systems before coming up with his own design. What makes ESIS different, he said, is it has five chambers, but no moving parts, and the finished wastewater is clean enough to discharge into the ground.

Unlike other septic systems that require pumping two to three times a year, Nagato's anaerobic system breaks down solids like a traditional sewage treatment plant and is pumped every two to three years.

"We were able to create a modular-size treatment system like Sand Island into a smaller unit and we can put it right next to your house," Nagato said.

Nagato prides himself on heading up a locally owned business that took its lumps early but persevered. In the early years, critics said his technology wouldn't work and there wasn't a demand for septic systems.

But Nagato stuck to his beliefs. He even serviced systems free of charge to build a solid reputation.

"We stood by our system and even though we weren't making money, you just go and do it because I wanted this thing to work," he said. "A lot of companies would send a manual and said that the system wouldn't break. I wanted people to know that there was somebody standing behind this product."

Environmental Waste Management Systems has eight full-time and six part-time employees. The parts for his tanks are manufactured in Vietnam and assembled at the company's plant in the old Waialua sugar mill.

He said increased environmental awareness, especially after last year's huge sewage spill into the Ala Wai Canal, has drawn more customers to his business. With no advertising budget, Nagato said his reputation is everything.

"There's going to be a big boom and it's already starting," Nagato said. "Now people are coming back and telling me, 'You're lucky you're in this business.' But that's not what they were telling me 10 years ago when they were calling me stupid."

Nagato is at the age when many of his friends are retiring, but he said he has a few good years left to continue his business. He said his son, Jon, has joined him and likely will take over the company.

"A lot of success comes from something that was needed. Everybody in their heart wants to be successful and we are looking for that niche. But how many of us say, 'I want to be a rubbish man' or 'I want to be the sewer man?' " he said. "My family for a long time would ask, 'Dad, what do we tell people that you do?' They were looking for all those fancy names, like environmental engineer. But now they're not too bad. They say, 'My father deals with wastewater.' "

Reach Curtis Lum at culum@honoluluadvertiser.com.