Some Economic Planning Considerations of Ground Water Pollution for the Upper Pawcatuck River Basin in Rhode Island

This study was concerned with the economics of supplying an area with water suitable for human consumption. The area chosen for study was the Upper Pawcatuck River Basin in Rhode Island, which h as the largest ground water reservoir s in t h e state. Since the people within and adjacent to the Basin depe'nd exclusively on water from these ground water reservoirs , this study investig ated a means of preserving the quality of the ground water so that other methods of supplying water , which might be more costly, would not have to be developed . These other methods would be necessary if' the g round water were allowed to become polluted . The hypothesis tested in this study was that the costs involved in developing a regional sewag e treatment and disposal sy s tem, together with a large scale municipal well development, are less than the development costs or an alternative means of supplying water for human consumption . The alternative means would be a surface impounding reservoir that would be necessary if the g round water were permitted to be polluted by sewage originating from private sewag e disposal facilities. In order to estimate the present deg ree or ground water pollution in the Basin, data which g ave the results of water quality tests performed on water from wells in the Basin were obtained f'rom the Rhode Island Dep artment of Health . I t was

iv found that although a serious widespread ground water pollution problem does not exist at the present time, the potential for areawide pollution problems in the future is present. A means of eliminating this potential was prop0sed to be the development of a regional sewage treatment and disposal system to eliminate the necessity of private sewage disposal systems (septic tanks and cesspools).
In order to test the hypothesis, cost data were obtained from vartous sources in order to estimate the development costs of a regional sewage treatment and disposal system, a municip al ground water development, and a surface impounding reservoir. It was found that the development costs of a municipal ground water development together with a regional sewage treatment and disposal system were less than the development costs of a surface impounding reservoir that would yield approximately the same amount of water.
Due to economic benefits and the effect that the provision of water supply and sewage disposal facilities has on land development and use, it was recommended that planning for these facilities should be done on a comprehensive basis that considers water supply and sewage disposal as a single function. The planner's role in the formulation of water and sewer plans should be that of an active participant and not merely an advisor to the engineer.   This usable water is obtained from both surf ace and underground supplies.
The fact that the country has an ample supply of water to meet total demands at the present time and for some time in the future does not mean that there are no problems associated with this valuable resource. First, it must be realized that the total quantity of water is constant. Therefore, population growth and an increased rate of consumption will increase the demand for water, while the total supply remains constant.
All problems of water supply are basically ones of quantity and quality. As more and more people occupy a particular area and as per capita consumption is increased 1 u.s. Congress Furthermore, the actual amount of water available in various parts of the country may vary widely. If the quantity of water is scarce in a region and transporting it to the region involves enormous costs, then the region cannot support very much human habitation, and the chances for growth are very small.
Although the actual amount of water in a region may vary by location and through time and also by the use man makes of the supply, concern must also be given to the quality of water, since quality determines the uses that will be made of the water. At the present time the question of water quality must be given more serious attention than water quantity. The fact that the people of the United States are using only a small percentage of the amount of water actually available for use, and also because .an increasing amount of water f s being reused, there appears no need for alarm that the country as a whole is heading toward a water shortage.
On the other hand, water quality has become a serious problem for if water is to be suitable for reuse, it must be free of harmful substances. Industrial use of water, the increased use of detergents, unsuitable private waste disposal systems, and t h e inadequacy and lack of sewage disposal facilities have threatened and in many cases lessened or destroyed the quality of many water supplies.
The Hydrologic Cycle water is considered a renewable resource because the supply at any place and at any time is dependent upon what is known as the hydrologic cycle. Through this cycle, the exchange of water between the earth and the atmosphere is effected by the heat of' the sun and the force of gravity.
The hydrologic cycle describes the circulation of' water from the ocean, to the atmosphere, te the land, · and back to the ocean.
If it is assumed that , , 1 the hydrologic cycle 'begins at the ocean, all usable water has its origin in the ocean, where it ultimately returns after preceding through the hydrologic cycle. When the sun heats the water in the ocean, evaporation occurs and thus places water in the atmosphene.
The process of evaporation may also occur from water round in ponds, lakes, and streams, and also f'rom ground water in areas where the water level is very close to the surface of the land. Water may also proceed t~ough the process of transpiration. The two processes of evaporation and transpiration are eommonly grouped together and ref erred to as the process of evapotranspiration.
Another phase of' the hydrologic cycle is precipitation.
Precip itation occurs when water vapor in the atmosphere is condensed. The air temperature is the controlling factor as to the a,IJ1ount of water vapo~ which the atmosphere can carry without loss by condensation. Precipitation occurs when m0ist air cools to the point when there is too nro.ch water for the atmosphere to hold as vapor. When this occurs, soine of the vapor changes to liquid water which falls due to the force of gravity.
The water that reaches land as precipitation may follow a number of courses. It may run off into stre ams, be discharged by evapotranspiration, or be stored underground.
Runoff consists of water that falls directly on the streams or runs over the land surf ace to them, and water that moves below the ground surface and discharges i nto the streams.
In areas where there is an abundance of rainfall, the water which reaches underground strata knc;rwn as 1t aquifers 11 represents a large portion of the supply available for human use.
In addition to the water that is confined, some water found in these aquifers is not static but flows to areas of natural discharge such as springs, ponds and lakes, swamps, and wells.
In analyzing and planning for the water needs of an area, attention must be given to all phases of the hydrologic cyo 1 e • Al though this study is primarily cone erne-d with ground water, the complexities of the hydrologie cycle indicate that no single phase of the cycle can be entirely divorced from the others.

Supply of Wat~'r in the United States
The amount of water available for human use in the A supply of 4,400 billion gallons of water per day seems immense; however, there are factors that make it possible to retain only 14% of this water for human use.
First, more than two-thirds of the water that reaches the earth returns to the atmosphere through evaporation and transpiration from plants. Of the water that is retained, problems -also arise due to such factors as excessive mineral content and pollution by l<>iologie al and chemical wastes.
The major problem concerned with the quantity of water in the United States is that the 30 inches of annual rainfall on the United States is not equally distributed.
Although the United States as a nation has a sufficient quantity of water to meet present and future needs, the 2 c.L. MeGuinness, The Role of Ground Water in the National Water Situation, Geological Survey Water-Supply Paper 1800 TWashington: United States Geological Survey, 1963), p. 10. irregular distribution of water over the country does not guarantee an adequate supply for all areas. From an economic ' viewpoint, any area that is lacking an adequate supply of water may obtain water from somewhere else if it is willing to pay the necessary cost of obtaining this water. However, the price in many cases may be too high for an area to bear.

Water Use in the United States
The use of water can be placed into two categories: consumptive use and non-consumptive use. Consumptive use refers to the use of water resulting in a large proportion of the water being lost to the atmosphere by evapotranspiration or being used in such a manner that the quality of the water is lessened to the degree that it cannot be used for any other purpose. An example of this type of use is irrigation, since irrigation water evaporates and transpires to the atmosphere or percolates into the subsoil. Non-c0nsmnptive use refers to a use of water that allows ' it to remain readily available for future use. Non-consumptive uses return water to a stream or to the ground in approximately the same quantity and quality as it was used previously.
The Senate Select Committee on National Water Resources in 1960 studied the use of water in the United States and also made projections of water use into the future.4 Table 1 shows  The projections that the Senate CoI1DJ1ittee made were based on the following assumptions: (1) that population and the national economy will continue to grow at past rates, (2) that adequate water supplies will be made ·available under present pricing policies, (3) that there will be little change in presently known technical methods of water use, and (4) that present inefficient methods of water use will continue except that irrigation efficiency will improve substantially.
Although the author feels that the last two assumptions may not be entirely valid,. in order for the Committee to make some kind of projections for the future, these assumptions were necessary.
.Another major assumption made by the Senate Committee was that there will be a great increase in the use of ground water as a source of supply. As present surface supplies are strained more and more, and as the cost of developing and transmitting surface water increases, ground water will grow in imp ortance in the national water situation.
lEtportance of Ground Water in the National Water Situation As mentioned earlier, ground water is just one phase of the hydrologic cycle. It can be found wherever and whenever openings below the surface are filled with water under hydrostatic pressure, and ground water moves whenever gravitational forces are great enough to overcome the forces of friction.
The fact that ground water is so abundant t~oughout the country h as enabled people to occupy areas that otherwise could not have been settled.
Ground water as a source of supply has definite advantages. First, it has a constant temperature that comes very close to the average air temperature. In addition, the quality of the water is consistent, and it usually is free of harmful bacteria. Evaporation occurs to a much smaller degree than in surface water. Also, wells can be installed at the place and time at which water is needed. The reason for the very small use of ground water has been the lack of knowledge associated with this valuable resource. As more information is obtained about ground water, its value as a source of supply can be expected to increase.
The main problem in the past has been that the actual amount of water available below the ground was not accurately known.
However, the U.S. Geologieal survey, together with many state and local organizations, has been conducting extensive tests and studies concerning ground water.
Although it is very difficult to measure ground water withdrawal on a nation-wide basis, estimates have been made. There seems to be little doubt that the use of ground W1 ·11 continue to increase in the future. As more knowwater ledge and data are obtained for various areas in the United states concerning ground water, as the number of potential surface reservoir sites is diminished, and as the cost of transmitting surface water to developing suburban areas increases, ground water will increase in importance as a source of supply. 8 Table 2 shows the predictions that the senate Committee had made, based on the assumptions given previously.
The assumption made by the Senate Committee that the withdrawal of ground water will increase by one-third to one-half each decade appears to be a valid one. By looking at the pumpage of ground water for past years, it can be seen that the Senate Connnittee•s predictions may be reached. Us.e c8llle f rom surface sources. These figures do not account for the use of water by small industries that were not included in the survey. These small industries may have used an additional 20 mgd, giving a total of about 55.5 mgd of non-public water consumed by industry. rt was estimated that less than 10 mgd was used for irrigational purposes in 1965. Most of this non-public irrigational use occurred in the potato growing area located in the southern part of the state. In 1965, approximately 3.5 mgd of non-public water consumption was devoted to residential use. This figure was arrived at by applying a 50 gallon per capita per day allowance to the 70,000 people in Rhode Island who were not served by the major public or institutional water systems.

Ground W ater Location and Use in Rhode Island
The surficial deposits found in Rhode Island which yield ground water are outwash and till. Outwash deposits are composed of well-sorted sands, and gravels and are the principal water yielding deposits. On the other hand, till is an unsorted mixture of boulders and cobbles and generally yields Water slowly to wells.
The ground water reservoirs in Rhode Island are supplied with water by (1) precipitation falling directly on the outwash deposits, (2) underflow from surrounding till, (3) leakage from swamp deposits and small channel storage, and (4) direct infiltration from streams crossing the outwash 1.5 16 water is diverted from the underground reservoirs bodies. bY the streams that drain the outwash deposits. These streams obtain a portion of their yearly flow and all of their dry weather flow from ground water.
Withdrawal use of ground water in the s tate of Rhode Island has been minimal. Table 4 is a listing of the estimated current withdrawal of ground water for the various river basins and areas in the state. Figure 1 shows the location of the river basins and ground water areas in Rhode Island. 1 7 The numbers on Figure 1 c 1 orrespond to the basins enumerated in Table 4.
The total withdrawal of ground water of 44.7 mgd represents but 2Wo of the estimated pumping capacity • 18 The pumping capacity is not the total amount of ground water available, but rather is defined as an estimate of the ground water that would be available if the low flow in the streams and rivers is to be maintained.

Role of Ground Water in the R.I. Water Situation
Althougih ground water is not being used extensively in the state at the present time, planning for the water supply needs of areas in the state must consider ground water as a source of supply. Tests and studies from the U.S. Geological

The Conservation of Ground Water
Once the potential value of ground water is understood, knowledge must be sought concerning the ways water is put into the ground and taken out, as well as the effect man's activities may have on -this natural resource. Although ground water development offers gr-eat potential in providing an adequate supply of water for the future, the danger of abusing this resource is also present. srstems are non-existent pose a threat to the quality of ground water. As development takes place, the danger of contaminating t h e ground water supply of an area may exist. This is the primary area of concern of this study.

DESCRIPTION OF THE UPPER PAWCATUCK RIVER BASIN
An appraisal of the ground water reservoirs in Rhode Island ma de in 1961 by the U.S. Geological Survey. 21 Areas demonwas strating ground water potential were ranked in order for the  O unts for most of the flow of streams during periods of ace no P r ecipitation. The remaining portion of the precipitati0n returns to the atmosphere through the combined process of evapotranspiration. Wherever water is exposed to the air or is available to. plants, evapotranspiration may take place • .Air temperature is the primary controlling factor in losses to the atmosphere through the process of evapotranspiration. Evapotranspiration is minimal during the winter when the temperature is low, but increases rapidly as air temperatures rise in the spring and summer. According to the u.s. Weather Bureau Station at Kingston, the mean annual air temperature is 49° F. 27 Figure 3 shows the relation between mean annual air temperature and mean :annual water loss in regions such as the Upper Pawcatuck .River Basin.
Evapotranspiration may occur from ground water as well as surface water. The amount of ground water lost through evapotranspiration in the entire Upper Pawcatuck River Basin in the 19.59 water year was 8.77 inche.s. 28 The water remaining after evapotranspiration losses have been satisfied is strea.mflow. This water consists not only of the water that moves over the land af'ter rains and melting of snow, but also ground water that seeps into the streams. Daily discharge records for two stations in the Basin and one station on the Pawcatuck River at Kenyon j~st below the boundary of the 27 Ibid., p. 17. m 28 Ibid., p. 25.
A water year is defined as the 12 onth period ending September 30 of the year designated.
UPPER PAWCATUCK RIVER BAS! N, RHODE ISLAND   was supplied to about 4,600 people. Table 5 is a summary of the water systems and their demands in 1965.    In order to determine the future demands for water, the estimate of the future population to be served has to be multiplied by the per capita consumption rate. On this basis, the demand for water in South King stown in the year 1980 will be approximately 2.6 mgd, which represents a 52% increase over the 1.65 mgd demand in 1965.
The town of Narrag ansett may also be expected to make a sed demands for water in the future . The construction inc re and i mprovement of highways and the con s true t ion of the bridge to Newport have placed Narragansett within easy c om..-rnuting distanc e of the Greater Provi dence Metropolitan Area . Planning f or Narragansett must consider its resort ch aracter ; however , the summer res ort nature of the town i s not as strong as it has been in the past . Redevelopment p lanning for the Nar ragan sett Pier area can also be expected to i n crease the growth p otential of the town .
In 1 965 , the Wakefield W ater Company wells supp l ied water to about 4 , 700 of the 5 , 0~-3 p erman ent residents of t h e t own . Since both the towns and villages in the Basin itself and those adjacent to it such as Wakefield and Pe acedale a.re exclusively dependent on ground water for their water supply, the importance of ground water to these areas cannot be overemphasized.

IV POLLUTION OF GROUND WATER causes of Pollution of Ground Water
-As mentioned before, all water problems are basically ones of quantity or quality. The prime concern in the arid west is water quantity, while water quality is the major problem in the east. Like surface water, ground water can be adversely affected by man's activities. Material such as sewage and industrial wastes may enter a ground water supply and pollute it. If pollution occurs to the degree that the water supply is hazardous to public health, then the supply is considered contaminated. Table 9 is an outline of the various causes of deterioration of ground water quality.  Pollution of ground water is not a problem that is restricted only to certain portions of the United States.
In 1960, the American Water Works Association made a survey or ground water contamination in the United States from information collected from replies to a questionnaire.
The survey revealed that: Of the 48 states that returned the questionnaire, 9 indicated no reported or observed contamination problems; 26 states indicated contamination by sewage; 22 reported oil and gas production waste or petroleum products contamination; 15 indicated other industrial waste or chemical contaminants; and 13 reported problems wh;ich developed from contaminants of another nature.43 The fact that only 9 out of 48 states had no contamination problems indicates that a widespread ground water pollution problem does exist.

Water Quality Analysis
In order to realize -the quality of a ground water supply, it must be determined what chemical, physical, and bacterial constituents are present in the supply. Standards must then be applied to determine whether the water is acceptable for a particular use. For the purpose of this study, it will be assumed that the water is to be used primarily for human con-  soo . s.
a Thi s is the limi t for Rh ode I s l a n d . nie l imit f or fluorides is based on the annual average of maxi mum daily air temp e rature . ABS is one of the major constituents of syndets, which are the popular synthetic detergents which are replacing soap a cleansing ag ent. The reason for the p opularity of as sYlldets is that, unlike soap , syndets do not require the interaction with calcium and magnesium to form a lather before the cleansing action starts. Since syndets are unaffected by h ardness salts in water, they are able to cleanse much sooner than soap.
Although syndets are very useful as cleansing agents, indicates pollution that has existed for some time.
The most dangerous of the nitrogen compounds are the nitrates. Nitrates usually occur in ground waters due to the excessive application of fertilizer or the effluent that enters the soil from septic tanks. Ground water polluted by nitrates has been known to cause serious blood changes in infants who consumed it. In some cases, ground water containing nitrates has proved fatal to babies drinking it.53 Nitrites are formed in water by the action of bacteria upon ammonia and organic nitrogen. Whenever nitrites are found present in a ground water supply in conjunction with ammonia and nitrates, this may signify pollution by sewage. Ground water may also be undesirable for human consumption due to its physical characteristics. Turbidity, color, odor, and taste may be reason enough for rejecting a ground water supply. Turbidity of water is a measure of the extent to which the intensity of light passing through is reduced by suspended matter such as clay, silt, and microscopic organisms. :Mineral or organic· matter in the water may be the cause of undesirable color, while tastes and odors may be uue to gases, mineral matter, or bacteria entering the ground water supply.
The following limits of turbidity, color, and odor have been defined by the U.S. Public Health Service. These are the levels at which these characteristics become objectionable to most people.  through what is known as the zone of saturation. Figure 6 shows these two zones.  In the case of bacterial pollutants such as fecal org anisms, the accumulation of sludge may cause the dangerous organisms to either never reach the water table or to be in a harmless state once they do. When bacterial pollutants mo~e through the zone of aeration, the pore spaces of the soil may become clogged causing the formation of a sludge

52
The sludge layer prevents the advance of the pollutants, and as the depth of the layer increases, the bacterial pollutants will eventually die since the close proximity of the organisms will prevent them from getting the oxygen necessary for their survival. The finer the grain of the soil is, the more effective this " chokingn process will be.
Even though bacterial pollutants may never reach the ground water due to the filtering action that may take place in the zone of aeration, the danger of organic pollutants originating in sewage or other sources may still be a hazard.
Organic matter is not removed as rapidly as the bacteria, since it requires oxygen for its mineralization. More significantly, mineralization occurs more effectively if the oxygen is atmospheric oxygen, which is found only near the land surface. In addition, organisms · that are capable of oxidizing org anic matter are also found near the land surface.
Therefore, org anic matter that is introduced at a substantial depth below the land surf ace may not be oxidized completely and may proceed through the zone of aeration to enter the ground water, thus polluting it. eir movement becomes altered, and movement in the lateral direction predominates. Furthermore, the pollutants move in the same direction as the ground water, which is towards areas of discharge such as stream valleys. In addition, the pumping 0f wells may divert the pollutants from their natural movement and cause the pollutants to enter the wells.
once polluted water has entered a well, it will flow radially outward from the well into the aquifer. This radial flow is controlled by the natural hydraulic gradient in the aquifer or by the gradients created by wells in the vicinity of the polluted well. Therefore, all wells that are in the proximity of a well containing polluted water are themselves in danger of pollution, since their pumping may cause water from the polluted well to be drawn into the unpolluted wells.
The mechanisms that affect the pollutants in the zone of aeration also act in the zone of saturation. These mechanisms include dilution, filtration, decay, and sorption.
However, it is extremely difficult to determine the exact effect of these mechanisms due to the tremendous variety of pollutants and also to the many hydrologic factors acting in the saturated zone. These factors include the geology, the hydraulic gradient, the permeability of the material, and the temperature of the water. Although it is beyond the scope of this study to consider all of the above factors, examples of the distances that some p ollutants have been known to travel can be cited.   Since the program is entirely voluntary, an assumption may be made that unless an owner suspects there is something wrong With his water supply, he most likely will not have a water analysis p erf,ormed. Therefore, there may exist in the Basin Polluted wells for which a water quality examination has never been performed. 5. Imperfections in construction and/ or placement of well and/or disposal system.
The following is a summary of the results of the individual tests of the 157 wells analyzed.
Overall Safety of the W ater Supply for Human Consumption 76 samples represented water safe at the tirae of collection of the sample ll samples represented water safe at the time of collection, but traces of harmless contamination were present.
2 3 samples represented water safe at the time of collection, but there were traces of harm.less contamination that were too pronounced to allow assurance that the water will remain safe.
14 samples indicated such conditions that it was doubtful if the supply could be made satisfactory. A recommendation was made that another supply should be sought. 88 samples showed that surface material was entering the well through the top of the well casing or other imperfection in the well. 76 samples showed that the sewage seepage system was located less than 100 feet from the well and/or on higher ground than the well. 31 sample s showed that a privy was located less than 65 feet from the well and/or on higher ground than the well. 11 samples showed that the location of the well in the basement of the building was unsafe. 9 samples exhibited the need for cleaning and repairing of the well in addition to chlorination.

Overall Safety of the Water Supply for Human Consumption
Of the t otal 157 wells tested only 76 were reported as being free f rom all contamination and safe for human consumption. Thus, only 48% of the priv ate wells tested had ground water that was phy sically, chemically, and bacteriolog ically safe. Thirty -four other wells supplied water that was safe for human consumption, but traces of harmless contamination were present. However, the fact that the contamination was hai-m.J.ess at t h e time of analysis does not insure that the water will remain safe in the future. Th e Heal th Department recommended that 14 other wells sh ould be discontinued as a source of water, and that anoth er supply should be sought.
The remaining 33 wells, therefore, supplied water that was not free of contamination, but yet could be used for human consUJlIPtion . The fact that only less than half of the wells tested were found to be supplying water with no trace whatsoever of harmful constituents indicates that pollution of ground water is a serious concern in the Upper Pawcatuck River Basin.

Bacteriological Examination Conclusions
The bacteriological characteristics rep orted for the 157 wells show that only 5 samples had satisfactory results, while 32 other wells had bacterial results that indicated the water should not be used for human consumption. Thus, 120 wells showed evidence of bacteria; however, at the time of testing , the water could still be assumed safe for human consumption. The fact that some harmful bacteria were detected may be an indication of problems at a later time.

Chemical Examination Conclusions
Approx imately 9/o or i4 of the 157 wells tested had completely satisfactory chemical results, while water from 11 other wells exhibited chemical qualities that were indicative of pollution to the degree that the ground water should not be used as a source of water supply. Only 9 wells supplied ground water that had chemical results which showed the presence of excessive amounts of synthetic detergent, While 7 samples indicated a presence of nitrates so high that the Health Department recommended that the water should t be consumed by infants due to the possibility of developno t of methemoglobinemia (blue baby). The remaining 116 men wells, therefore, supplied water that exhibited traces of chemical pollution, but the ground water was not considered dangerous to health, and could continue to be used provided tbe chemical pollution does not increase. In summary, the potential for chemical pollution problems in the majority of wells exists.  The most dang erous source of ground water pollution has been shown to be the sewage that enters the ground through the use of septic tank and cesspool disposal systems on individual lots. A means of eliminating this hazard would be the development of a municipal or regional sewag e treatment system. This chapter is concerned not only with the development costs of a regional sewage treatment and disposal system, but also with the development costs of alternative means of water supp ly: ground water and surface water. It is hypothesized that savings can accrue to the Upper Pawcatuck River Basin regi on in the long run through the develop ment of the ground water reservoirs found in the Basin, together with a regional s ewage treatment and disposal system to eliminate the sewage that is presently being disposed of below ground.

71
There are serious problems associated with the use of home waste water disposal systems. First, periodic cleaning of the septic tank is essential because no matter how efficiently the septic tank digests the solids, the material that builds up in the tank must be pumped out. If the built up sludge is not pumped out periodically, solids will escape from the tank together with the liquid wastes and pose a potential pollution hazard for the ground water. Furthermore, the improper location of the septic tank disposal system could cause pollution of the well, as has been found to be true in many cases in the Upper Pawcatuck River Basin.
From an economic point of view, individual disposal systems are not the most efficient means of disposing of sewage. Not only are the initial installation costs generally higher than the cost to connect to a central system, but also the maintenance costs for septic tank disposal systems are from $40 to $100 higher per year than the normal sewer use charges of a central system. 6 3 Furthermore, even under perfect c0nditions, the disposal of sewage by means of individual septic tank systems is a temporary measure.
Not only will the septic tank disposal system fail in the long run functionally, but also areas where development 63 Intergovernmental Res onsibilities for Water Sup !lld,Sewage . isposal in Me ropolitan .Areas as ing on: Advisory Commission on Intergovernmental Relations, 1962), p. 26. becomes dense will eventually require the abandonment of private sewage disposal facilities and connection with a nrunicipal or regional sewage treatment and disposal system due to the considerable land area necessary for these systems to operate properly. Development Costs of a Regional Sewage Treatment and Disposal §.Ystem In 1968, Charles A. Ma guire & Associates of Providence prepared a report for the town of Narragansett proposing was. te water collection and disposal facilities when it was found that the existing public sewage treatment and disp osal facilities did not meet the general needs of the state to preserve the shorelines and reduce pollution. 6 4 In the report, joint facilities with the town of South Kingstown and the University of Rhode Island were recommended since the town of Narragansett would find it difficult to support financially such a venture independently.
The need for sewage treatment and disposal facilities for the W akefield-Peacedaie area of South Kingstown has been recognized for a long period of time. In addition, although the University of Rhode Island has its own sewage treatment and disposal facility, the plant is overutilized. The University is presently increasing the capacity of its sewage treatment p lant by 50%. However, even with the expansion, the plant will not be able to accomodate any additional sewag e t· over the expected amount to be treated in 197 2 . The University's sewage treatment plant will not be able to be enlarg ed further because the effluent from the plant discharges into a brook which flows west from the campus into wordens Pond. The formation of alg ae on the pond has become a serious concern of homeowners in the area. This pollution problem has been publicized in the local newspaper and has become a concern of state officials.
Lt. Gov. J. Joseph Garrahy authorized an investigation of a thick, green algae which this year covered most of W ordens Pond, and which area residents fear may destroy the waterway before a proposed regional sewer system can be constructed. The Wordens Pond Homeowners' Association which brought the complaint to the lieutenant governor, charged that algae are being nourished by effluent from the University of Rhode Island sewer plant.65 In June 1969, a plan was approved for the development of a combined sewage treatment plant and outfall system that would initially serve the town of Narragansett; the villages of Wakefield, Peacedale, and Kingston in the town of South Kingstown; and the University of Rhode Island. Figure 8 is a schemmatic representation of a system such as the one that has been approved, while Table 14 shows   ' .i:: T!J.erefore, for comparison reasons the cost of lateral lines in the public sewerage system was left out.

2.
3. aOther costs include site acquisition for pump station and treatment plant, engineering, supervision of construction, and project contingency.

Source: Charles A. Maguire & Associates
The estimated population and flows of waste for South Kingstown and the University of Rhode Island that were used in the design of the proposed sewage treatment and disposal system give a good indication of the amount of sewage that could be expected to enter the ground if such a system was not to ·be developed and people living in these areas continued to depend on private sewage disposal systems. It DlU.st be emphasized that the projected population and flows are only for a very small portion of the Basin. In the future, other areas may be serviced by tying into the proposed system. Furthermore, it should be emphasized that the liquid effluent from the regional treatment plant will not be returned to the ground water supply, but will rather be discharged into Narragansett Bay, thus leaving the ground water supply in a naturally pure state. Table 15 shows the projected population and waste water flows that were used in the de sign.

Development Costs of a Large Scale Ground Water Supply
The development of a large scale municipal well system in the Up p er Pawcatuck River Basin can be advocated for several reasons: 1. Well water developments on individual lots are a short run method of providing an adequate supply of water. As further development takes place, some -areas of the Basin may not be capable of yielding a suffic.ient quantity of water. e.g.
areas underlain by bedrock.
2. There exist two extensive ground water reservoirs in the central part of the Upper Pawcatuck River Basin that are capable of supplying water not only to the communities in the Basin itself, but also to surrounding areas.
3. A municipal water supply sy stem could be a tool for planning the future development of the Basin by - 8Th is is the population estimated to be living in the areas of Wakefield, Peacedale, and King ston for wh om sewers are being considered.
bThis is the ncampus Pop ulation 1 and i s comp osed of all enrolled undergraduate students; staff and faculty , taken according to the Universit y of Rhode Island analysis as 23.5 per 100 resident undergr aduate s ; and graduate s t u dents.
• 0 Thi s p opulation is taken as 2/3 of the winter p opulation. W ith summer school, conference s and p ermanent staff, the campus remains generally 11 full 11 , ex cep t for fraternity and sorority houses according to campus auth orities.
<\le ighted aver age of summer and winter populations using three months for the summer p eriod.
Source: Charles A. Maquire & Associ ates providing water to particular areas where development is desired.
As was mentioned in an earlier chapter, even though the privately owned Wakefield Water Company is the largest supplier of water in the Upp er Pawcatuck River Basin, the majority of households in the Basin depend on individual wells for their water. Table 16 shows the development costs associated with a public well system, developed by the Wakefield Water Company, that is capable of yielding 1.6 million g allons of water per day at a development cost of $14 7 ,500.  -The hypothesis of this study was that there exists an economic advantage in developing the ground water reservoirs iocated in the Upper Pawcatuck River Basin, together with a regional sewage treatment and disposal system to eliminate the sewage that is presently being disposed of below ground.
Economic savings would occur as a result of eliminating the development costs associated with a surf ace water supply that would be necessary if the ground water supply should become unsafe for human consumption.
In order to compare the development costs of the regional sewage treatment and disposal system and the ground water development with the costs of the surface water development, it was necessary to bring the development costs presented earlier in this chapter up to date. The development costs presented in Table 14 for the sewage treatment and disposal system were based on July 1968 prices and therefore had to be updated. This was done by taking the 1968 sewage treatment plant cost index and °1968 sewer construction cost index in Engineering News-Record and dividing them into the appropriate indexes for 1969 and then multiplying the resulting factors times the previous costs for the individual items.70 As can be seen from Table 19, the updated development cost for the sewage treatment and disposal system was $3,040,000.
( . Engineerin~ News-Record New York: McGraw-Hill, December 18, 1969 , p. 88. This updated figure represents a 21.6% increase over the development cost given in 1968.

2.
3.    This study has indicated that the development costs associated with a larg e scale ground water development and a re g ional sewag e treatment and disposal system a.re less than the development cost of a surface impounding reservoir that would yield approximately the same amount of water.

4.
Thus, the concern has been not only with alternative methods of water supply, but also with the quality of water supplied.
It was assumed that the water would be used primarily for human consumption, since this use requires water of the highest quality.
I t is the purpose of this chapter to examine some of the p roblems encountered in supplying an area with an adequate supply of water suitable for human consumption, and in disp osing of the sewag e that may pollute that supply.
Since this study has been. concerned wholly with capital costs, an explanation of the other land development costs will be given tog ether with a very general exp lanation of the use of benefit-cost analysis in the planning of water reso~ce developments. F inally, the benefits of comprehensive water and sewage development will be g iven, tog ether with t h e role of planning in that dev elopment.

problems at the Local Level
In order to arrive at some conclusions as to how suburban communities may be adequately supplied with pure water through a publicly operated water supply system, it is necessary first to examine the problems that have traditionally arisen. The first and most serious problem of water supply and sewage disposal at the local level has been inadequate investment in these facilities. As in the case of the town of South Kingstown, the members of the community had been unwilling for 10 years to accept the initial cost of a sewage treatment and disposal system. A regional system serving parts of the towns of Narragansett and South Kingstown and the University of Rhode Island was approved 10 years after it was discovered that: (1) Narragansett 1 s small system was not adequately treating the sewage; (2) private sewage disposal systems in the Wakefield-Peacedale area of South Kingstown were failing; and (3) the University of Rhode Island system could not accomodate any additional sewage after 1972. Thus, the heart of the problem of inadequate investment has been the communities' reluctance to increase local expenditures in order to prevent the pollution of the shore areas, but more importantly to prevent the pollution of the ground water supply on which the area is presently dependent. Only when the pollution problem had become serious was the system approved.
A second problem that has arisen in the provision of water supply and sewage disposal facilities at the local level has been that of fragmentation. Fragmentation of facilities for each locality has been due to each community's desire to maintain control over its local tax rate.
very seldom have individual suburban communities been willing to take part in a water or sewerage system that could The Wakefield Water Company, a priv ate regional distribut ion system, provides water to parts of South Kingstown and Narragansett. However, there were oth er parts of both town s which were in need of municipal water, but the Wakefie l d W ater Company was not able to extend service into the s e areas. Traditionally, this has been due to the fact that private water companies are a part of the private enterprise system and therefore are able to extend service only to areas that promise the largest returns and must leave the more remote districts without a supply. As a result, Narr ag ansett has been forced to develop its own municipal distribution system to serve areas in the southern and north- Individual wells and septic tanks, which previously were only used in rural areas, were introduced in the new settlements.
What resulted was that development began to spread out in Which must be considered in any type of land development.
Although it was not the purpose of this study to analyze the time costs associated with the two alternative methods of water supply, it should be mentioned what these tirae costs include and how they might affect the two methods of water supply which were considered. The fact that the ground water system could be developed as needed by drilling additional wells, while the surface system must be developed all at once, may mean that the ground water system has an additional economic advantage over t h e surface system when waiting and ripening costs are considered. Later studies could investigate to see if t h is were actually true.
Of direct concern to t h is study is the fact that the (1) project costs, (2) associated costs, and (3) secondary costs. Project costs consist of the value of the land, labor, and materials that are necessary in developing and operating a project, plus an allowance for any undesirable effects that may result from the project.
Ass ociated costs include the value of any addi~ional materials or services which may be needed to make the products or services of a project available for use or sale. F inally, secondary costs include the value of any goods or services in addition to project and associated costs that are used as a result of a project. They include the cost of processing any p roducts or services which may result from a secondary benefit of a project. F or example, t h e cost involved in op erating a frei gh t terminal which was built adjacent to a new highway would be considered a secondary cost.
Benefit-cost an alysis involves more than just determining what the benefits a_Dd costs of a project are. Questions such as the following must be answered: In addition to being an attempt at correcting problems that -. may exist in the present, planning may be viewed as a process to foresee future requirements and t o aim for the provision of those requirements in an economical fashion.
Traditionally, water supply and sewage disposal h ave been developed and ad_rn.inistered as separate functions by individual co:m:nrunities. Undesirable results su ch as urban sprawl have resulted from this practice. The fact that the two fun ctions are so interrelated demands that they be considered as one service. Furthermore, because water has no regard for political boundaries and because of the econoraic benefits that could be realized by areawide planning, development of water supply and sewage disposal systems should be undertaken on a re g ional basis, which would serve areas of need and not necessarily watershed areas.
Economies of scale are the most convincing argmnent for t h e development of water supply and sewage disposal systems on a re g ional basis. The disadvantages of fragmentation have been discussed earlier in this chapter, and it was shown that small facilities have r arely provided a long-range solution to the water supply and sewage disposal problems. Table 23 shows how economies of scale are realized wh en sewage treat-