History of the Water Supply of the World / arranged in a comprehensive form from eminent authorities, containing a description of the various methods of water supply, pollution and purification of waters, and sanitary effects, with analyses of potable waters, also geology and water strata of Hamilton county, Ohio, statistics of the Ohio river, proposed water supply of Cincinnati.

by Thomas J. Bell

SPRINGS AND WELLS.

We have, under this name, nature’s resources for supplying our wants, whose facilities for furnishing the requisite supply depend upon the local rain-fall, configuration of the land, and the nature, or geological formation, of surface and subsoils.

Land springs are fed by rain-water, gravitating through loose permeable soils. The waters are very readily affected by infiltration of surrounding soils, and their course so easily changed in any direction that the permanence of such a source can not be relied upon.

Deep springs are fed by the waters falling upon and soaking down to great depths, and find their way to the surface through some fault, upheaval or other great geological disturbance, or between some impermeable strata. The most copious springs are in the tertiary strata, and the law, as regards their abundance, is “the rarer the visible springs may be, the more copious they would be found.” The permanence of the springs can only be relied upon after careful gauging, extending over several years.

Wells may be separated under the following divisions:

Shallow, or dug wells.
Ordinary deep, or pump wells.
Artesian wells.

“Shallow and deep wells are those which are sunk through a permeable stratum, and form, as it were, reservoirs, into which the land springs may filter and accumulate; whilst artesian wells are those which are sunk through an impervious upper stratum, to reach a subterranean water-bearing stratum lying, in its turn, upon an impervious upholding bed. In the former cases, the quantity of water obtainable is simply that which can filter through the sides of the well to replace the water removed, or which may accumulate in any reservoir formed below; whilst, in the latter case, the quantity obtainable will depend simply upon the power of the water-bearing stratum to transmit water.

“In the case of deep-seated wells, the probable yield of water must depend, primarily, upon the area of permeable strata likely to affect the supply, and upon the facilities those strata may offer for the passage of water; and, secondly, upon the rate of consumption which takes place in the neighborhood, for the quantity of water which any particular stratum can supply is only a limited quantity; so that, evidently, if the water be taken at one point, no more will remain for the other.”—(Hydraulic Engineering, Weale’s Series.)

The above fact is illustrated, practically, in London, where the water line of the chalk formation has been permanently lowered to the extent of fifty or sixty feet below Trinity high-water mark; and it is even stated that the level of the water in the wells, near the summit of this formation, rises, on the Monday morning, in consequence of the cessation of pumping in London during the Sundays. The experience of Liverpool corroborates this fact: that the Windsor well, having a depth of 210 feet, affected the surrounding wells to a maximum distance of a mile and three quarters. The celebrated engineer and originator of the well system of Liverpool, Robert Stephenson, from long experience and careful observation, offered the following conclusions (from Hughes water-works):

“That an abundance of water is stored up in the new red sandstone, and may be obtained, by sinking shafts and driving tunnels, about the level of low water.

“That the sandstone is generally very pervious, admitting of deep wells drawing their supply from distances exceeding one mile.

“That the permeability of the sandstone is occasionally interfered with by faults or fissures filled with argillaceous matter, sometimes rendering them partially, or wholly, water-tight.

“That neither by sinking, tunneling, nor boring, can the yield of any well be very materially and permanently increased, except so far as the contributing area may be thereby enlarged.

“That the contributing area to any given well is limited by the amount of friction experienced by the movement of the water through the fissures and pores of the sandstone; and

“That there is little or no probability of obtaining, permanently, more than about 1,000,000 or 1,200,000 gallons a day from each well, and this only when not interfered with by other deep wells.”

Statistics of the flow of the Windsor well show that the yield, in 1843, was 1,152,000 gallons per day; in May, 1848, 807,061 gallons; in January, 1850, from 705,667 to 634,752 gallons. The observations of the Green Lane well, in the same city, give the decrease in flow, per annum, at 4.7 to 6 per cent.

A plan has been proposed, by Mr. Bailey Denton, that, in order to increase the water-bearing stratum under London, sufficiently for a water supply, and also secure the well-known benefits of the filtration powers of the chalk, to let the Thames water pass down to the chalk, through the London clay, by means of wells sunk or bored. The objections raised against this plan is the possibility of the wells becoming choked by accumulation of impurities.

Mr. J. T. Fanning in his valuable “Treatise on Water Supply Engineering,” says:

“The success of wells, penetrating deep into large subterranean basins, upon the first completion, has usually led to their duplication at other points within the same basin, and the flow of the first has often been materially checked upon the commencement of flow in the second, and both again upon the commencement of flow in a third, though neither was within one mile of either of the others. The flow of the famous well at Grenelle was seriously checked by the opening of another well at more than three thousand yards, or nearly two miles distant.”