Tkias 



744 REPORT — 1893. 



regards drainage and water-supply. As regards the former the drainage of the 

 houses for the most part was run off into cesspools sunk in the sandstone rock on 

 which the town is built ; and as regards the latter the water-supply was drawn 

 from wells sunk through the same formation down to the water-level, so that often 

 the cesspools and wells were in proximity to each other. The result of such a state 

 of affairs may easily be surmised. However excellent as a filter may be the sand- 

 stone rock, it must assuredly become clogged with faecal matter when filtration of 

 water is carried on for an indefinite period, subject to such contamination as is 

 here referred to, and in course of time the water from the wells becomes unfit for 

 drinking and household purposes. 



Now all this is changed : the cesspools have been closed or filled up, and the 

 water-supply is drawn Irom large and deep wells far removed from possibility of 

 contamination. 



Few towns in central England are more favourably situated for purposes of 

 water-supply than Nottingham. Built on a foundation of New Red Sandstone and 

 conglomerate, which rises at the Castle in a precipitous cViS above the valley of 

 the Trent, the formation on which the city stands in its prolongation northwards is 

 a source of water- supply of the highest excellence, and yields several millions of 

 gallons per day of pure water from three or four wells situated within a few miles 

 o-f the city. 



The conditions which render this formation so well adapted for water-supply 

 may be briefly explained. The succession and character of the strata all combine 

 towards this end. 



In descending order the succession is as follows : — 



'Keuj)er Marls . . . Red and variegated marl, shaly and 



gypseous (slightly permeable). 

 Waterstimes and Loiver Laminated micaceous sandstones 

 Kevpcr Handdone alternating with marls and shales. 



Bunter Sandstone . . Soft yellow and reddish sandstone 

 I, and conglomerate (permeable). 



IRed Calcarcovs Marls . These are the strata separating the 

 Upper and Lower limestones of 

 the Worksop district to the north 

 (impervious). 

 Loiver Magnesian Lime- Sandj' magnesian limestones. 

 stone 



From the above succession it will be seen that the permeable beds of the Bunter 

 Sandstone, about 200 feet in thickness, are underlaiu by impervious marls of the 

 Permian series, which thus form a water-tight floor, effectually preventing the water 

 which percolates downwards from the surface to escape into the magnesian lime- 

 stone ; and, as the beds dip eastwards at a small angle from the western margin of 

 the formation, an underground reservoir is thus formed M'ith a naturally permanent 

 level corresponding to that of the springs which break out at the junction of the 

 sandstone with the marl along the western outcrop. 



The proportion of the rainfall, taken at an average of 30 inches, which sinks 

 down into the Bunter Sandstone north of Nottingham must be very large owing to 

 the absence of drift deposits and the sandy character of the ground. As there is 

 no surface drainage the percolation cannot be less than about 20 inches per annum, 

 giving a supply of about 1,000,000 gallons to every 3 square miles. Taking the 

 area of the formation between Nottingham and Worksop at 120 square miles, the 

 amount of water which annually percolates into the rock and becomes a reservoir 

 of supply may be estimated at about 40,000,000 gallons per day. 



This large quantity of water tends to flow eastwards, following the dip of the 

 beds; and that it has permanently saturated the Bunter Sandstone under an exten- 

 sive area occupied by the overlying formations is proved by the result of the boring 

 at Scarle, near liincoln, which, commencing in the Lower Lias, passed down through 

 the Keuper marls into the Bunter, when the water came up with force and flowed 

 over the surface.' This boring is at a minimum distance of 20 miles from the 



• Two feeders of water were struck— one at a depth of 917 feet in the Lower 

 Keuper Sandstone, and the other at 1,250 feet in the Bunter Sandstone. 



