The site does not seem to be very up-to-date.

Here's an extract from the cesspit section.

"A common practice in parts of Kent was to knock the bottom completely out of cesspits and this would allow more to drain away into the chalk. Although this meant that they didn't need to be emptied so often, it was rather shortsighted since wells took water from the same chalk! Water from the chalk of the Medway area is still high in nitrate content for this reason. Archaeological excavation of a cesspit is not everyone's choice but analysis of the soil content can yield interesting insights into the diets of people using it.

Many cesspits would have been filled in when abandoned but some were merely covered over with a slab or wooden cover. Examples open up from time to time but they are rarely deep enough to present a danger. In some places, however, houses adapted abandoned deneholes as cesspits that were ideal since the underground space meant that they never needed emptying. The top part of the shaft was lined with bricks and arched over at the top, sometimes with a small access hole. Earthenware pipes directed the sewage into the shaft and this has caused problems in the past where the brick lining has been eroded and fallen away."

Also water cisterns.

"Another underground feature found in bigger houses was the water cistern. This was a large brick-lined chamber that was made watertight and arched over with a small access hole. Rainwater from the roof was directed into the cistern where it could be stored for future use, being softer than water drawn from a well in the chalk. Sometimes a pipe connected the cistern to a hand pump in the kitchen. Like cesspits, a number of water cisterns were merely slabbed over when abandoned but the workmanship often means that the brickwork is still sound."

Penny