When the Rivergate Pump Station in North Portland began to jam with clothing, construction materials and hypodermic needles in April, the source of the debris was a mystery.

The underground station takes sewage that’s been flowing downward along a gravity-powered path and pumps it upward to higher ground. From there, the sewage continues its journey to the city’s wastewater treatment plant to be treated.

When a city sewer pump jams, it can cause raw sewage to back up into homes and businesses, leak out into the street and possibly end up in storm drains that lead to the Willamette River.

Because raw sewage contains some pretty nasty bacteria, such as E. coli, these overflows can spell a public health emergency and an environmental mess.

Of notable concern, the Rivergate Pump Station happens to sit adjacent to nearly 2,000 acres of wildlife habitat in the Smith and Bybee Wetlands Natural Area. It’s the largest protected freshwater wetland within an American city.

This photo shows the close proximity of the city’s Rivergate Pump Station (at left), located at the corner of North Rivergate Boulevard and Time Oil Road, and the Smith and Bybee Wetlands Natural Area. Note the “Wildlife Habitat Area” sign posted on the gate to the right. At nearly 2,000 acres, the natural area is the largest protected freshwater wetland within an American city. Photo by Emily Green

Depending on the volume and velocity of the spill, an overflow at that location could have potentially flowed into the river or affected wildlife. The habitat is home to many species, including river otters, black-tailed deer, beavers, Western painted turtles, Chinook salmon and 100 types of bird, such as bald eagles and ospreys.

When the Rivergate station jammed nine times over 10 days, officials in Portland’s Bureau of Environmental Services knew they had to pinpoint the source of the problem as soon as possible.

Luckily, each time the main and secondary back-up pump at the station were jammed with debris, triggering an alarm, crews arrived in time to clear the clogs and reinstall the pumps before an overflow occurred.

Debris, such as beverage cans, caught in and below a catch screen intended to keep debris out of the city’s sanitary sewer. Photo from Portland Bureau of Environmental Services investigation

Any facility with a permit to discharge into the city’s sanitary sewer system is required to have safeguards in place to keep large solid materials from entering the system.

For this reason, one theory floated early on in the city’s investigation was that someone might be illegally dumping clothing and other garbage directly into the sewer, according to internal city emails.

But a city inspection of the area’s manholes yielded no evidence of such dumping.

The focus of the investigation changed when the city discovered a Honey Bucket storage facility on North Rivergate Boulevard, just north of St. Johns, had recently obtained a wastewater permit to begin emptying its porta-potties onsite.

The site’s wastewater system had passed inspection in February, and its Industrial Wastewater Discharge Permit from the city had been approved.

The day Honey Bucket began discharging wastewater toward the Rivergate Pump Station, however, was the day the pump began to clog.

“That was the big smoking gun,” said Dan Parnell, Bureau of Environmental Services industrial permitting manager.

Over the course of 10 days, the only day the city’s sewer pump didn’t jam was the only day Honey Bucket didn’t discharge wastewater, according to city documents obtained through a records request.

Debris similar to the items that clogged the city’s pump was discovered onsite at Honey Bucket in its catch basins, according to city inspectors. They noted a beverage can and hypodermic needles floating in the company’s septic tank. These items had to pass through all the safeguards, which rely mainly on workers’ diligence, and a catch screen to arrive at that location, Parnell said.

Debris that jammed the pumps at the Rivergate Pump Station. Photo from Portland Bureau of Environmental Services investigation

As it turns out, people discard all sorts of items inside Honey Buckets, which are often used at construction sites, music festivals and other outdoor events. Tom Rogers of Northwest Cascade, Honey Bucket’s parent company, told city regulators that workers regularly find everything from beer cans and Gatorade bottles to bras, underwear and other items in Honey Bucket porta-potties.

When employees clean out the toilets, they’re supposed to fish out large items and throw them away. Additionally, before the water enters the onsite septic system, it has to pass through a screened drain that should stop any items that were missed by workers.

But city inspectors discovered the Honey Bucket facility manager had cut a 2-inch by 24-inch hole in one of the screens intended to keep debris out of the sewer – a major permit violation. Additionally, a pipe had been replaced to alter the facility’s septic flow – another serious violation.

An arrow points to a 2-inch by 24-inch hole cut in the screen leading to the city’s sanitary sewer system, a permit violation. Photo from Portland Bureau of Environmental Services investigation

“I’ve been in this business for 16 years now, and that’s the first time I’ve had a permittee that has drastically altered a treatment system like that without prior approval,” Parnell said.

If the hole had been cut in the screen to begin with, the permit would never have been approved, he said.

The alterations were made between the time city inspectors approved the permit and the time Honey Bucket began discharging wastewater.

Representatives from Northwest Cascade argued that the hole was cut to allow large “turds” to pass through the screen and that any other material would have been removed by employees. At some facilities, the company uses a Muffin Monster industrial sewage grinder to chop up large solids before they enter the sewer, but it doesn’t have this machinery at its North Portland location.

Industrial sewage grinders that chop up large non-fecal debris for discharge – which are commonly used by municipalities and porta-potty companies – cost about $100,000, according to a quote Street Roots requested from a manufacturer.

But Northwest Cascade might not be saving much in the way of costs. The city has fined the company $90,000 for violations, plus $3,592 for the cost of the pump fixes and inspections that required more than 80 labor hours.

The company has appealed the fine, first going through an administrative hearing in September, where the company’s attorney, Steve Parkinson, pointed to the city’s premature theory that illegal dumping could be the cause of the clogs.

“We do know that there’s, you know, homeless encampments immediately down the street from us, between us and the Rivergate pump station,” he said, according to a transcript of the meeting. “I know that one of the theories put forward by the investigators that’s in the record is it was, you know, homeless folks or other people dumping stuff down manholes.”

Later during the hearing, Parkinson admitted, “I think it’s fair to say that what a homeless person could dump down a manhole – just to be, you know, fair – they could find a Honey Bucket and open the Honey Bucket, and dump it there.”

The bureau upheld the fines, and Northwest Cascade is continuing to fight them. A Nov. 2 appeal is scheduled before a hearings officer in the city auditor’s office.

According to the appeal documents, Northwest Cascade is still clinging to the city’s early theory that the cause of the blockages was illegal dumping.

“The City mischaracterizes Northwest Cascade’s position that all of the debris was deposited by homeless people between April 5 and April 14th (the dates of the pump jams). While such material could have been dumped down manholes at this time – as acknowledged by the City – this material could have been dormant in manholes and was mobilized by the increased discharge volume starting on April 5, 2017,” argues the appeal.

One problem with this argument, city officials said, is that while the increased flow could have dislodged built-up debris when it began, it doesn’t explain the eight subsequent clogs.

Additionally, for people to dump directly into the sewer between Honey Bucket and the pump station, they would need a large hook to remove one of the 50-pound circular steel manhole covers first, Parnell said. All manhole covers were in place when inspected, and there were no signs any had been removed.

Northwest Cascade is also arguing that the workers at its Honey Bucket facility “will testify that they never pushed any large debris through the slit.”

“When (Honey Bucket) finally fixed their screen and fixed their septic tank and they discharged, it stopped. We no longer had any issues,” Parnell said. “And to me, that’s the definitive proof right there.”

Should the city auditor’s hearings officer side with the Bureau of Environmental Services, Northwest Cascade could file an appeal in circuit court.

“They’re just trying to grasp at straws,” said Matt Criblez, an environmental compliance officer with the city. “It’s a very large penalty.”

Citing the ongoing appeal process, Northwest Cascade declined to comment for this story.

Email staff reporter Emily Green at emily@streetroots.org; follow her on Twitter @greenwrites