Stanley hands over a laudatory profile of Raleigh's sewer maintenance department in a recent issue of Municipal Sewer and Water magazine, then hands me off to Robert Smith, a sewer monitoring supervisor and asks him to show me around.
First things first: We walk the yard, checking out trucks. Sewer guys basically do three things: They perform maintenance, they respond to crises, and they "TV" pipes, sending tiny little vehicles with cameras on them up the pipes to check both their condition as part of general maintenance and whether the crews who claim to have recently maintained them have actually done so.
Smith shows off the department's various trucks. Rodder trucks have a spool of linked rods, a sort of long chain that the workers feed into a manhole and then rotate, just like someone cleaning roots or a clog out of your drain at home. Some rodders have cutting blades or spiral grabbing implements to clear roots or debris. Flushing trucks carry enormous water tanks to feed high-pressure hoses with spinning heads on the end: Workers feed the hose into the system, usually past the next manhole, and then turn on a pump. Water pressure starts the head spinning, spraying water at thousands of pounds of pressure per square inch back toward the truck as the truck pulls back the hose, scouring the pipes along the way. Standard now is the combination truck, which carries tanks of water for flushing and a garbage-truck-size tank for postflush water, which the truck vacuums up with a huge tube that hangs from a derrick over the cab like an elephant's trunk. The driver eventually empties that tank onto a pad in the parking area, Smith explains; water drains off into the sewer system and the cleaned-out debris--tampons, bricks, gravel, roots, supposedly flushable materials--gets loaded into a dump truck once a week and sent to the landfill. Smith marshals those vacuum trucks when Raleigh has a sewage overflow, too. Another truck he calls a blockbuster has a water hammer--a pipe that uses water to rhythmically pound and break up large blockages. Finally, he shows me a sort of souped-up golf cart that provides access to the many parts of the system that, because they follow ravines rather than roads, are not easily reached by regular trucks.
But we're standing in a parking lot while people are out in the field, rodding sewers. "Hey," he says. "You wanna shoot the line?" You bet.
Our first stop is a highway off-ramp, where two flush trucks and a pickup are parked behind orange cones. Several men wearing hard hats, green mesh vests, and rubber-palmed gloves manage a hose coming off a spool on the back of one of the trucks and running to a manhole 20 feet down a steep ravine. A hundred yards away, two guys stand at another manhole looking out for the spinning head of the water jet, which Smith says is called a Warthog. Once it's past, the guys still at the truck turn on the jet and the spool to start reeling it back in. Over the roar of the truck engine Smith explains that on the way out the head sprays as a sort of presoak; "on the way back, it's like a broom." Water-jet cleaning like this is standard for clearing roots, grit, and, especially, grease: "We run into some lines [where] you think, Where in the world did all this grease come from? It looks like you sprayed foam on that pipe." Because the bell-and-spigot joints in sewer pipes provide places for tiny tree roots to enter, and because trees got very thirsty during the drought, crews commonly run a saw through the line after cleaning just to make sure they've got everything. Where the vacuum trucks can't reach a manhole, the crew flushes debris downstream to one the truck can reach.
That's sewer flushing, and the sanitation department does it all day long. Ever since the Hamburg sewers first captured tidal water and then released it all at once to flush out debris, the basic idea hasn't changed much: You use water to flush, you use rods or hooks to attack clogs, and, as Ed Norton sang, you keep things rolling along.
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16 Comments
Add CommentExcellent article, kudos to SA for reprinting it. I've been studying water and wastewater treatment with an eye toward employment. The more I learn, the more impressed and fascinated I am by the ingenuity that had made WWTPs amazingly efficient and virtually smell-free, producing very clean water. It's unfortunate that most people can't or won't ever visit one of these high tech plants to see how much they aren't like you'd expect, and how sensible it is to re-use tertiary treated water.
Reply | Report Abuse | Link to thisRecycled water is the only thing that makes sense in a space colony. Of course, you could reduce all the water in sewage to hydrogen and oxygen, then burn it, if you have enough energy. I'm always looking for alternative concepts. Got ideas?
Reply | Report Abuse | Link to thisExcellent article, with information that should be, but is generally not, understood by citizens. Many still protest the fees they must pay for wastewater treatment as part of their utility bill. I hope this lengthy article can be condensed into newspaper features and municipal handouts to better educate citizens about a vital service. The city of Arcata, CA, has a very interesting wastewater treatment system that may warrant the attention of the author and readers. Link: http://www.cityofarcata.org/departments/environmental-services/water-wastewater/wildlife-sanctuary
Reply | Report Abuse | Link to thisone of the best articles i've read in along time....contained both historic and current detail...thanks Scott for your effort...this should be one of the main articles in sciam...not just a link to the side...then again 11 pages might be to much for most;-)
Reply | Report Abuse | Link to thisThe four letter word for this stuff is actually an old acronym from the days of sail. When guano (bird droppings) was discovered in huge quantities on pacific islands and transported back in bales in the cargo holds of wooden sailing ships, any stored in the very bottom would get wet, give off methane gas which would be ignited by any sailor with a candle doing inspections. Several ships were lost before survivors told of huge explosions and fires that happened during inspections and the problem and mystery was resolved. Thereafter, maritime laws required all guano bales be marked "Store High In Transit".
Reply | Report Abuse | Link to thisQuestion; Does it make sense to pump city water from wells (from the aquifer) use it, treat it, and dump it in the river-shed?
Reply | Report Abuse | Link to thisA rural home pumps from a residential well, uses it, treats it and returns it to the ground. Not a river headed for the Gulf of Oil.
I agree wholeheartedly with several others here that this was a fascinating and well-written article. Who knew sewage treatment could be so interesting?
Reply | Report Abuse | Link to thisA well written story on the history of used water distribution and treatment around the world. Ending off with a a fine and entertaining write up on the process of water reclamation. I love the point which says that what the used water treatment plant is doing is in fact mimicking what the river is doing, just quicker!
Reply | Report Abuse | Link to thisA well written story on the history of used water distribution and treatment around the world. Ending off with a a fine and entertaining write up on the process of water reclamation. I love the point which says that what the used water treatment plant is doing is in fact mimicking what the river is doing, just quicker!
Reply | Report Abuse | Link to thisThis is hogwash, or perhaps a good example of the word it purports to define. See the Etymology section of http://en.wikipedia.org/wiki/Shit, which shows the origins going back to Roman times.
Reply | Report Abuse | Link to thisThis text was meant to reply to the comment on the origin of the s-word, not a comment on the article or reply to any of the other comments:
Reply | Report Abuse | Link to thisThis is hogwash, or perhaps a good example of the word it purports to define. See the Etymology section of http://en.wikipedia.org/wiki/Shit, which shows the origins going back to Roman times.
The article itself was wonderful, a fascinating read, with a mind-boggling amount of information I could hardly wrap my mind around (though Mr. Huler's style certainly was as clear as . . . triple-treated waste water!).
I live in flat Phoenix and I'm really wanting now to know how our system works. And all the other infrastructure we ignore but wouldn't want to be without these days.
Thanks for the kind words; mm, you beat me to the punch on the etymology. And in answer to Quinn, no, I don't think that makes sense; surface water -- like water from a reservoir -- basically just makes its way to the ocean through the city and its residents. That's where it was going anyhow, so wastewater generated by a community with surface water as its source can reasonably be released back into the stormwater system -- the riverbasin from which it emerged.
Reply | Report Abuse | Link to thisAquifer water is on the same journey, but it may take much longer, and continued pumping from an aquifer can deplete it; using septic systems to replace wastewater from such systems into the aquifer is probably a wiser move. Just the same, in my experience most houses on pumps -- using aquifer water -- are also using septic systems too, so the wastewater just trickles back into the ground.
There's a long chapter in "On the Grid" about stormwater -- much current stormwater treatment is about keeping it where it lands and helping it soak into the earth, instead of using curb and gutter to sluice it into creeks. It has a job to do as part of the hydrological cycle, and we do ourselves and the planet no favors by getting rid of it so quickly.
Many sewerage treatment stations only work at around 15% efficiency, because the operators cut the electricity supply to aerators and turbines to reduce expenses. The liquids that are then put into rivers are therefore a serious cause of pollution.
Reply | Report Abuse | Link to thisPyrolysing sewerage is a new, simpler and cheaper technique that should totally replace traditional plant. See www.eprida.com for more details.
How sewage treatment works in this country is so complicated! Why all the bother?
Reply | Report Abuse | Link to thisThey've got it figured out in Kibera; who needs sewers? Just poo in a bag and throw it in the street!
Thank you for this article; it has been a wonder to me that we honor or police and firefighters (rightfully so) but never give a second thought about those water and wastewater professionals who also keep us safe and healthy day in and day out. This too is a dangerious profession, there are more people who die in water/wastewater industry than in the police/fire profession. Again, kudos, keep up the good work.
Reply | Report Abuse | Link to this@cwclark: I did not know that -- do you have a source for that statistic? It's important and I will share it. Thanks for your kind words.
Reply | Report Abuse | Link to thisScott