Archived report · 2 min read · Set in Gold Street ·
Sewer Inspection Under Gold Street
A drainage survey of the Gold Street sewer finds a side tunnel that does not appear on any plan, lined with brick and carrying a small clean stream, and the camera at the far end records a shelf of identical clay jars that are refilled each night.
- filed: Filed with the water authority's infrastructure register
- reference: DR/GS/09
Subject: combined sewer, Gold Street, manhole sections 14 to 22, with lateral connections.
1. The sewer was laid in 1881 as a brick-lined circular culvert, 1.2 metres in diameter, and was last surveyed in 2012. The drawings show six lateral connections, all of which were confirmed on inspection.
2. The camera survey began at manhole 14 and proceeded downstream. At manhole 17 the footage shows a seventh lateral, not on the drawings, entering the culvert from the east wall at knee height.
3. The lateral is a brick-lined tunnel approximately 60 centimetres in diameter. The camera could not enter it under the standard procedure. A clear, shallow stream of water flows out of the tunnel into the main culvert at a steady rate. The water is not sewage. Laboratory analysis found it to be pure spring water, with no contamination.
4. A second camera, lowered on a cable from the street through a trial hole in the road surface, reached the lateral from above. It recorded a series of brick arches, each supporting a small shelf, and on each shelf a clay jar with a cloth tied over the mouth.
5. Eleven jars were visible on the footage. The surveyor counted them twice. Each jar was full and sealed. The clay had the appearance of old pottery, and the cloths were of a coarse weave consistent with linen.
6. Repeated footage taken at the same time the following night showed the same eleven jars, but each had been opened. The cloths had been removed and folded. The water level in each jar had risen to the rim.
7. Recommendation: the lateral to be sealed at the point of entry pending investigation. The contractor declined to carry out the sealing on the grounds that the tunnel was, in his words, already busy.
8. Observation not explained by the survey: the surveyor, reviewing the footage at his desk, noticed that the time stamp on the second camera reads 03:12 throughout, although the survey began at 14:00. At the bottom of the screen, in the reflected light of the stream, a figure is visible, bending over the jars and filling them one by one, moving with the unhurried care of someone who has done this many times before.