Setting out into the warm night with exploring in mind, Nancy Drew and I cruised to a far side of the city. After parking the car, we donned the gear of the drain explorer- rubber boots on our feet, flashlights pocketed and ready. We walked across a brightly lit lot, with our eyes on the entrance ahead. I pulled on some gloves, and waited for the break in traffic that would allow us to hurredly slip down the hole into the musty darkness below.
I strapped my headlamp on in the darkness, water dripping all around me, before descending the ladder. Many meters down, we entered a large concrete tunnel, our boots sloshing in several inches of clear water. The pitch-black, enclosed environment of the storm sewer system was familiar, even though I'd never been inside this particular pipe. Excitement gripped me- this section of the sewer trunk line was unexplored, and we were about to find out what wonders were hiding in its depths.
I took the lead and chose to head upstream, the light of my LED headlamp dimly illuminating the tunnel directly ahead. Immediately, I became aware of a very slippery layer of muck coating the bottom of the pipe under the water. I slid a few times, until I decided to start carefully placing my feet to maintain my balance as we walked along.
The tunnel we were in was a large, round pipe, about 2.4m in diameter. The walls were made up of joined concrete sections, causing me to wonder what method the city had used to build the sewer. We walked on into the darkness, and came to a 90 degree bend where the pipe turned to the right and shrank slightly. The concrete in the bend had been poured around wooden frames; the boards used left impressions in the walls. Ahead, the pipe jogged slightly, and we entered an oddly shaped tunnel. Known as double-barrel pipe, it is basically an RCP with an interior wall dividing two sides (storm and sanitary sewers). The storm sewer side is always larger, and I was grateful for this as I walked along, feet sloshing through shallow water.
Talking as we walked, I listened to the way our voices and the sound of splashing water echoed down the tunnel. A small patch of foam floated by on the water's surface. We passed a sidepipe or two, where water splattered down from a dropshaft above. In turn, we stepped over an errant sandbag that had blocked the flow of water and created a small dam, backing up a small lake of foam-covered water. I spotted a strange white shape in the dark ahead, which turned out to be a large clump of white foam. I remarked that someone had probably been washing their car and the soapy water had drained into the storm sewer, creating the foam.
This guess seemed plausible, until we walked a few more meters and spied an impossibly large white mass in the tunnel ahead. As we approached, I almost couldn't believe my eyes. A huge buildup of the mysterious foam blocked the tunnel ahead, from floor to celing. Curious, I ventured into the frothy stuff, stopping when it became waist-deep. I noticed that the foam was leaving a strange white residue on my pants, which didn't brush off. I was just able to see overtop of the white mass, and noted that the tunnel seemed to end a few meters beyond. Unwilling to become coated in the strange white stuff, tiny particles of which were becoming airborne, I retreated to take some photos from a safer distance. After posing for a few photos, Nancy Drew commented that she was getting a headache from the foul air.
We decided to turn back, and discussed the strange foam as we walked. Nancy Drew did her best to splash me with drain water, in an effort to wash the strange white film off my pants. I doubt the foam was a natural occurance, and wondered what chemical or soap was causing it- and where it was coming from.
Returning to the large tunnel with the slippery floor, we decided to head downstream. The floor became even slicker the further we went, making each step treacherous. In the lead once again, I had to slow my walking speed in order to avoid an unpleasant bath in the drain water. We walked on for at least ten minutes, the gray pipe ring sections fading into the distance.
Eventually, I spotted a bend in the line ahead. The pipe curved to the right, and ended in a gaping black hole. Excitement building, I used my large flashlight to examine what lay beyond. The tunnel ahead was huge, probably about 3.5m in diameter, and stretched beyond sight in both directions. I eagerly climbed down and stood in the sandy bottom of the larger pipe, and marveled at the space. Even the beam of my largest flashlight faded into the distance, and I wanted to set off immediately and hike right to the end; but the hour was getting late and we both had to work in the morning.
Settling for a quick look around, I immediately noticed another large pipe that emptied into the main trunk line. The air wafting out smelled strongly of sewage, and the opening itself was encrusted with multi-colored slime deposits, small puddles of grayish water covered the floor. I couldn't resist checking it out, and climbed up inside. A rusty safety chain hung across the pipe, and the reek of sewage was powerful. The walls were covered in mineral deposits, and tiny bits of debris clung to the walls and arched ceiling. A few steps ahead, I could see double-barrel pipe like the one we'd just been in. The difference was that this one had a small trail of grayish sewer water flowing out of it, into a tiny plastic diversion pipe. The smell was unpleasant enough that I decided not to explore the pipe; instead shooting a few photos before returning to the huge trunk line.
As much as I wanted to further explore the large, seemingly endless tunnel, I knew that it would be best left for another day. After packing up my tripod, we headed back up the slippery pipe to the exit. After climbing up the ladder past the dripping water, I waited at the top for a break in traffic before emerging into the cool night air. Reveling in the night's adventure, we kicked our damp boots off into the trunk, and headed home.