Ground Water in the Norwalk, Suffield, and Glastonbury Areas, Connecticut

Some of the part of Suffield west of Peak Mountain ridge drains to Salmon Brook in Granby and so is tributary to Farmington Eiver, and some of it drains to Congamond Pond and is tributary to West- field River. Most of the town, however, is drained by Stony Brook, which joins Connecticut River near the southeast corner of the town. About 6 square miles is drained by short brooks that empty directly into the Connecticut. WATER-BEAEING FORMATIONS. Traf Tock. — The trap rocks of Suffield do not constitute an impor- tant source of ground water. They do contain some water in joints and fissures, but the hardness of the rock makes its recovery difficult and expensive. Moreover, the resistance of the trap to erosion leaves it in unfavorable topographic forms, so that much of the water drains away and many of the fissures are dry. Sandstone. — Considerable amounts of water are recovered by means of wells drilled in the red sandstone in Suffield. The unconsolidated soil above it absorbs a good deal of rain and snow water and trans- mits it in part to the joints and fissures made in the bedrock by the SUFFIELD. 143 crushing and jostling incident to tilting and faulting. The fissures tend to fonii s.ysteins of parallel fissures, which are in gener-al roughly parallel to the bedding planes or at right angles to them. The rocks, then, are cut by an intricate network of interconnecting fissures from which water ma^^ be recovered by drilled Avells. Some of the coarser sandstone beds may contain water in the interstices between the grains, but this is not an important source of supply. It is highly probable that a liole drilled at any point will cut one or more water- bearing fissures within a reasonable distance and so obtain a satisfac- tory supply. Twenty-six such wells were visited in Suffield in August, 1916. The data collected concerning tiiein are summarized in the following table : ISiuiniiari/ of drilled icells in Suffield. Total depth. Depth to rock. Depth to water in well. Yield per minute. Maximum Feet. 288 63 161 Feet. 100 1 44 Feet. 90 0 25 Gallons. 135 6 Average .- 39 I'HL — About 13 square miles or 30 per cent of the total area of Suffield is mantled with till. There are a few large patches and a number of small ones. Their distribution has been discussed above and is also shown on the geologic map (PI. V). The till was depos- ited by the plastering action of the glacier and consists of all the debris of the ice, the smaller particles forming a matrix in which the larger are embedded. As the whole mass is tightly packed and the smaller particles are fitted into the chinks between the larger, the total porosity and the size of the individual pores are small. A fair proportion of the rain that falls on the till is absorbed and slowly transmitted. Wells dug in till are in general satisfactory, espe- cially if they are so deep as to penetrate the saturated zone just over the bedrock, or if they happen to cut one of the masses of partly washed and sorted material that exist in some places in the till. Measurements were made of 35 wells dug in till in Suffield. The dependability of 27 of these wells was ascertained; 19 were said to never fail and S were said to fail. The data collected concerning the depths of these 35 wells are summarized in the following table : Summary of wells dug in till in Suffield. Total depth. Depth to water. Depth of of water in well. Maximum. . . Feci. 40.8 7.2 22.3 Feet. 3,1.9 4.4 12.9 Feet. 15.9 Minimum 2.6 9.4 144 GROUITD WATER IN NOEWALK AND OTHER AREAS, CONN. Strcdified drift. — The mantle rock of tlie lower parts of Suffield is stratified drift, which is composed of the reworked material of the till plus some debris derived from the erosion of the bedrock. Streams issuing from the glacier during its recession had high velocities and bore much debris, but they were soon slowed up and forced to deposit much of their load. Thus beds and lenses of sand and gravel were deposited near the glacier, whereas the finer and lighter debris was carried farther away and ultimately deposited as clay and silt. By this process the debris was sorted into beds in each of which the grains are of uniform size, and the finer grains were eliminated from the interstices between the larger. The strati- fied drift is therefore not only high in porosity but has relatively large and open pores. For these two reasons it is an excellent water-bearing formation except where it has an unfavorable topo- graphic form, as on terraces from which water may drain readily. Measurements were made of 44 wells dug in stratified drift. Of these wells 23 were said to never fail and 17 were said to fail; the reliability of the remaining 4 was not ascertained. The information collected concerning the depths of the 44 wells is summarized in the follovvdng table : Smnmary of wells dug in stratified drift in Sv/fjield. Total depth. Depth to water. Depth of water in well. Maxirnum Feet. 34 8.3 17.8 Feet. 27 5.2 11.9 Feet. 16.6 1.7 Average .• . . . 5.9 QUALITY OF GROUND WATER. The accompanying table gives the results of two analyses and four assays of samples of ground water collected in the town of Suffield. These waters are moderately mineralized except No. 35, which is low in mineral content, and No. 99, which is high. No. 35 is a very soft water ; No. 32 is soft ; Nos. 36, 93, and 97 are hard for this section of the country; and No. 99 is very hard. Nos. 36 and 99 are considered to be poor for use in boilers because they contain ex- cessive amounts of scale- forming ingredients. Nos. 93 and 97 con- tain rather less scale- forming ingredients and would probably be fair for boiler use. Nos. 32 and 35 are good for boiler use. So far as their mineral character is concerned, all the waters are ac- ceptable for domestic use except No. 99, which is very hard. Nos. SUFFIELD. 145 03, 07, and 00 are calcium-carbonate in type; Nos. 32 and 35 are sodinni-oarbonate; and No. 3G is a calcium-sulphate watc^r. Clicnihol con; position and classifiration of ground loaicrs in liufflcld.'^ (Parts per million. Collected Dec. 6, 191fi: analyzed by .\lfred A. ChainV.crs and C. H. Kidwell. Numbers of analyses and assays correspond to those used on PI. IV.] Silica(SiO;) Iron ( Fe) Calcium (Ca) Magnesium (Mg) Sodium and potassium (Na+K) d. Car lionate radicle (CO3) Bicarbonal e radicle (IICO3) Sulphate radicle (804) -. Chloride ladicle (CI) Nitrate radicle (NOs) Total dissolved solids at ISO" C Total hardness as CaCOs Scale-forming constituents d Foaming constituents d Chemical character Prolmbility of corrasion*^. Quality for boiler use. . . . Quality for domestic use . Analyses.'' 21 .14 15 6.6 42 .0 90 17 45 .05 191 d65 76 110 Na-COs N Good. Good. 36 32 .19 C,5 17 26 9.1 102 176 5.0 .10 391 d232 250 70 Ca-S04 (?) Poor. Fair. Assays, c 12 .0 27 3.0 5.2 9.1 35 30 Na-C03 N Good. Good. 93 196 23 46 d 300 178 200 100 Ca-COs (?) Fair. Good. 97 25 196' 23 19 0.07 404 45 : 260 162 190 70 d530 375 400 110 Ca-C03 I Ca-COs (?) I (?) Fair. Poor. Good. I Bad. a For location and other descriptive information see pp. 146-148. b For methods used in analyses and accuracy of results see pp. 52-60. c Appro.ximations; for methods used in assays and ;-ehabillty of results see pp. 52-60. <i Computed. <■ Based on computed quantity; N=noncorrosive, (?) = corrosion uncertain. PUBLIC WATER SUPPLIES. The residents of Suffield viilag-e and its environs are served by the Northern Connecticut Light & Power Co., and a few on the Avest bank of Connecticut River opposite Thompsonville are served by the Thompsonville Water Co. See p. 136.) The Northern Connecticut Light & Power Co.. which began the distribution of water in 1805 under another name, has two drilled wells (Nos. 108 and 108A, PL IV) in the northeast part of the town from which water is drawn by electrically driven pumps with their working cylinders about 220 feet below the surface. Water is de- livered to a steel standpipe that has a capacity of 300,000 gallons on a hill a m.ile north of the village, from which it is distributed under a pressure of 45 to 50 pounds to the square inch through 13 miles of main to 34 nre hydrants and 301 service taps. There are 326 customers in Suffield and 12 in Agawam, Mass.,^ and the average daily consumption by the 2,560 people served is about 52,000 gallons. The maximum consumption comes during* the tobacco-planting season and is estimated by Mr. W. P. Schwabe, the superintendent, at about 140,000 gallons a day. ^ Connecticut Public Utilities Commission Rept., 1917. ir,4444°— 20 10 146 GROUND WATER IN NOEWALK AND OTHER AREAS, CONN. ItECGRDS OF WJILLS AND SPRINGS. Two springs were visited in Suffield (Nos. 49 and 79, PL IV). Spring No. 49 is piped by gravity about 200 feet to the house and is said never to fail. Spring No. 79 was improved by setting a barrel In it. The lower head was left in the barrel but was perforated by a number of ^-inch holes. Wetls dug in till in Suffield. "No. on PL IV. Owner. Topographic situation Eleva- tion above sea level. Total depth Depth to water. Depth of water in well. Rig Remarks. 87 93 95 99 103 104 105 106 W. H. Peckham. E. M. Austin . . Fred Brown. Slope. Ridge. Plain Ridge Slope Ridge Hill do do Slope Plain Slope Hill Plain Terrace . . . Plain do Slope.. Hill... do. do- do. Slope.. Hill.. Slope. do. Plain.. Slope. Hill.. Slope.. ICnoll. Slope.. Plain.. Slope.. Ridge. Feet. 285 270 245 245 225 220 225 215 165 195 190 160 185 165 185 185 215 165 170 165 ISO 180 195 180 140 130 130 110 160 175 125 110 90 Feet. 12.6 26.5 17.4 20 18.2 21.8 26.0 21.4 23.6 12.4 22.2 27.5 21.0 9.2 21.4 22.8 9.6 21.0 26.7 16.5 24.1 22.3 26.8 48.8 27.3 15.5 29.6 18.7 39.7 24.5 20.4 36.2 7.2 25.6 16.4 Feet. 8.2 23.9 11.1 16 9.2 10.4 10.6 14.4 10.6 9.0 11.6 14.7 8.4 6.0 7.5 16.3 4.4 14.7 13.4 13.2 13.3 10.1 13.9 30.9 15.1 16.6 15.0 18.8 14.1 6.8