In 1870 the wells measured 505 feet deep. Around 1876 there had been trouble with sewage contamination and many cases of typhoid. This resulted in the deaths of five patients. Lining the wells to try to stop further contamination was estimated to cost between £3,000 and £4,000, which was considered too expensive. To reduce the cost, it was decided to use the asylum bricklayers to cement the old linings of the wells.
