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A simulation approach to the historical reconstruction of the water-distribution system in the Dover Township area required knowledge of the functional as well as the physical characteristics of the distribution system. Accordingly, six specific types of information were required: (1) pipeline and network configurations for the distribution system; (2) potable water-production data including information on the location, capacity, and time of operation of the groundwater production wells; (3) consumption or demand data at locations throughout the distribution system; (4) storage-tank capacities, elevations, and water-level data; (5) high-service and booster pump characteristic curves; and (6) system-operations information such as the on-and-off cycling schedule of wells and high-service and booster pumps, and the operational extremes of water levels in storage tanks. These data types are discussed in detail in this section of the report.
DISTRIBUTION-SYSTEM NETWORK CONFIGURATIONS
The spatial configuration of the distribution-system networks, pipeline characteristics, and in-service dates of groundwater wells and elevated and ground-level storage tanks were obtained from the water utility (Flegal 1997) and the annual reports of the Board of Public Utilities, State of New Jersey (1962�96). For the water-distribution system serving the Dover Township area, pipeline, groundwater-well, and storage-tank locations are shown on an annual basis for the historical period of 1962� on Plates 3 through 37. Selected examples of historical network configurations for 1962, 1971, 1988, and 1996 are also presented in Figures 5 through 8, respectively.
Pipeline characteristics such as the material type, the year installed, length of pipeline segments, and the range of diameters are listed in Appendix A, Tables A-1 through A-35. Because the pipeline database did not specify the month of installation, an assumption was made that the in-service date for the pipelines was January 1 of the installation year as obtained from the water utility抯 database.
Spatial and temporal distributions of waterdistribution system facilities also are illustrated on Plates 3 through 37. Figures 5 through 8 assist in showing that the complexity of the system increased considerably over the time span of the historical period. The distribution system expanded from the south-central area of Dover Township along a northeasterly and northwesterly direction (compare Plates 3 and 7). In 1962, the water-distribution system consisted of three wells and one storage tank and standpipe combination (Figure 5, Plate 3). As storage tanks and groundwater wells were added, these facilities were brought online to meet yearly maximum demand, which occurred from the end of May (Memorial Day) through September. For example:
Therefore, according to the water utility, these additional facilities would have been operational after the end of May 1967 and May 1971, respectively.
To meet increasing demand in the Berkeley Township area, the Route 37 ground-level storage tank was added to the system in 1978 (Plate 19). To supply additional demand occurring in the northwestern area of Dover Township, well 31 (Route 70) was added to the system in 1980 (Plate 21). The Windsor ground-level storage tank was added in 1982 to meet the growing demand in the southeasternmost part of the distribution system (Plate 23). By 1986, customer growth and demand had increased substantially in the Berkeley Township area serviced by the water utility, and two additional supply wells, 33 and 34 (Berkeley) were added (Plate 27). In 1988, well 35 was added to the existing two wells serving the Berkeley Township area (Figure 7, Plate 29), and in 1991, well 40 (Windsor) was added to the system to meet increases in demand in the southeastern part of Dover Township. The last storage tank added to the water-distribution system during the historical period was the North Dover elevated-storage tank, and it was added in 1992 (Plate 33). Additional supply wells were added to the Parkway well field to meet increasing demand in 1993 (well 41, Plate 34) and 1994 (well 42, Plate 35). For the last year of the historical period, 1996, the water-distribution system (Figure 8, Plate 37) closely resembled the present-day system (1998) shown on Figure 3 (Plate 2).
The pipeline data were carefully checked and quality assured. At some locations, duplicate pipeline segments were identified, and at other locations, a few pipeline segments were missing from the original database provided by the water utility. At these locations, pipeline data for several years prior to and after the period of interest were compared in order to reconcile discrepancies. Such data discrepancies, however, generally accounted for less than 1% of all pipeline segments for any one historical year.
The time distribution of total pipeline length by material type and customer served is shown in Figures 9 and 10. The information shown in these figures are also listed in Appendix A. The distribution by year of pipeline material types (Figure 9) is shown as a percentage of total pipeline length. The graph shows that the distribution system is composed of pipelines whose material types are primarily asbestos cement (AC) and plastic (PVC, PE, IPS). The percentage of pipeline segments constructed of other material types, such as cast iron, copper, ductile iron, or galvanized pipe, has historically ranged between 7% in 1962 to about 2% in 1996 of total pipeline segments. After 1980, an increase occurred in the use of plastic pipe with a corresponding decrease in the use of asbestos cement pipe. Year-by-year total pipeline length of the water-distribution system and the corresponding number of customers served are shown in Figure 10. The increase in pipeline length and customers served occurred at a nearly identical rate throughout the historical period. Thus, as the number of customers needing potable water increased from 1962 through 1996, so did the length of the pipelines in the water-distribution system serving those customers.
To verify that pipelines located near the ends of the distribution network were in use and delivering water to customers (as opposed to being constructed in anticipation of future use), historical aerial photographs of the Dover Township area were obtained from the Ocean County, New Jersey, Planning Board (Scott M. Cadigan, written communication, December 4, 2000) and from IntraSearch, Inc. (Jerry T. Flickinger, written communication, July 11, 2001). Eight of the photographs shown in this report (Plates 38�) are overlain with water pipelines and other features in the Dover Township area for 1963, 1965, 1968, 1972, and 1976.
The aerial photographs reproduced on Plates 38 and 39 show areas serviced by the water utility during 1963. The photographs were taken in June 1963 and show the central (Plate 38) and west-central (Plate 39) areas of Dover Township. Houses and buildings can be seen in the photographs along the water pipelines at the ends of the pipeline network. These photographs provided evidence that, in 1963, the water-distribution system was servicing customers located near the ends of the network pipelines.
The aerial photographs reproduced on Plates 40 and 41 show the areas serviced by the water utility during 1965. The photographs, taken in April 1965, show the central area (Plate 40) and northeasternmost area (Plate 41) of Dover Township. Houses and buildings can be seen along and near the ends of the water pipelines. Such associations provide additional photographic evidence that the water-distribution system was servicing customers in 1965 located near the ends of the pipeline network.
The aerial photograph reproduced on Plate 42 shows the southwestern area of Dover Township serviced by the water utility during 1968. Houses located next to the water pipelines can clearly be seen in the photograph, thereby providing additional photographic evidence that the water pipelines were servicing these residences in response to demand.
An aerial photograph of the northern area of Dover Township, taken in April 1972, is reproduced on Plate 43. Overlain on the photograph are water pipelines showing the northern extent of the pipeline network. Residential communities can clearly be seen in this area being serviced by the northern extremities of the pipeline network.
Aerial photographs for the northeasternmost and western parts of Dover Township are reproduced on Plates 44 and 45, respectively, and are overlain with the 1976 water pipelines. Residences and buildings can be clearly seen next to the water pipelines at the extremities of the pipeline network, again providing photographic evidence that customers near the ends of the pipeline network were being serviced by the water utility. Furthermore, the photographs reproduced on Plates 44 and 45 show residences and buildings located beyond the extent of the 1976 pipeline network. Plates 44 and 45 provided photographic evidence that demand for water existed in these locations prior to the extension of the pipeline network to service customers. After reviewing aerial photographs like the ones reproduced on Plates 38 through 45, and following discussions with water-utility managers, ATSDR investigators concluded that the network of water pipelines was expanded based upon existing demand, rather than constructing water pipelines in anticipation of demand. Thus, for the historical reconstruction analysis, it was assumed that all pipeline segments at the extremities of the water-distribution system were delivering water to customers to meet demand.
Water-production data梫olumes produced and hours of operation for groundwater wells梬ere gathered, aggregated, and analyzed for each well for every month of the historical period (420 months), and these data are listed in Appendix B (Tables B-1 through B-35). Production data were obtained from the water utility (Flegal 1997), annual reports of the Board of Public Utilities, State of New Jersey, (1962�96), and NJDHSS (Michael P. McLinden, written communication, August 28, 1997). Well-production volumes were measured using in-line flow meters at water-supply wells (George J. Flegal, Manager, United Water Toms River, Inc., oral communication, August 28, 2001). Also listed in Tables B-1 through B-35 are well-identification numbers, the rated capacity of wells, the gallons of water the wells produced each month of the year, and the average number of hours each day a well operated. To determine the average number of hours each day a well operated, the following formula was used:
where:
Tavg = average times a well was operated, in hours per day;
QP = production of water, in gallons per month;
Cw = rated capacity of the well, in gallons per minute;
Tm = number of minutes per hour (60); and
Td = number of days per month (28, 29, 30, or 31).
For each well listed in the tables in Appendix B, the top row provides the reported gallons of water produced for a particular month and the bottom row indicates the average number of hours each day a well operated for the particular month, determined by applying Equation (1). The estimation of the average hours per day that a well was operated (Tavg) was based on the assumption that the well operated at its rated capacity.
Upon reviewing the data in Appendix B, the minimum production month is typically February, the average (or mean) production month is typically October, and the maximum (or peak) production month is either May, June, July, or August. Figure 11 is a graphical summary of the production data in Appendix B for each year of the historical period (1962�). The graph shows the minimum, mean, and maximum production for each year as a series of bars. The production values shown on the graph were derived by dividing the monthly production data (Tables B-1 through B-35) by the number of days in the month in which the minimum, mean, or maximum production occurred. For example, total water-distribution-system production for February 1964 was 30,432,000 gal of water (Table B-3). Dividing the production by 29 (the number of days in the month for February 1964) provides a value of 1.0 Mgal which is the value of the minimum-value bar for 1964 in Figure 11. Minimum and mean production values generally show increases of similar rates throughout the historical period. However, the maximum production for certain years peaks or "spikes" noticeably throughout the historical period (for example, 1971, 1980, 1988, and 1995), as shown on Figure 11.
Monthly production data also can be represented graphically as shown in a three-dimensional plot (Figure 12). Referring to this plot, the x-axis is the year (1962�), the y-axis is the month (January朌ecember), and the z-axis is the total monthly production in million gallons. Maximum production of water is shown to occur in the months of May, June, July, or August. In addition, considerable production increases are shown to have occurred in 1971, 1988, and 1995. These years are characterized on the plot by sharp peaks. The graph also shows that a small peak occurred in November 1989 when production for the month increased substantially (see Table B-28).
As previously discussed, the rated capacity of the groundwater wells that historically were used for production was required to compute the average number of hours each day a well operated (Equation [1]). The rated capacity for each well that historically was part of the water-distribution system is also listed in Tables B-1 through B-35. These data are summarized in Figure 13 as a series of bars, with each bar representing the total rated capacity of all wells in the water-distribution system for each year of the historical period.
Data listed in the tables of Appendix B are grouped by well number and well field or points of entry to the water-distribution system (for example, Holly wells, Parkway wells, Berkeley wells). Using production data in Tables B-1 through B-35, the percentage of water produced by each well field (or individual well such as well 15 (Brookside), well 20 (Indian Head), well 31 (Route 70), Silver Bay well, and Anchorage well) relative to the total production of water for each year of the historical period was computed. The percentage of production is shown in Figure 14 as a series of pie charts, with each pie chart representing the total production in million gallons for each year of the historical period. The size of the individual pie chart is proportional to the total annual production. The different slices of a pie chart represent the percentage of water produced by a well or well field for a given year. Using information in Figure 14, relative changes over time in the production of water from all well and well fields to the water-distribution system can be determined. For example:
The percentage of the total annual production of water listed in these examples was estimated by inspection of the pie charts in Figure 14. For a more precise derivation of the percentage of production of water by well or well field, readers should refer to the production data listed in Tables B-1 through B-35 and compute the percentages using these data.
ESTIMATION AND DISTRIBUTION OF HISTORICAL CONSUMPTION
For the purpose of the historical reconstruction analysis, the total monthly well production described previously (Tables B-1 through B-35) is considered also to represent total water consumption6. Water-consumption data applied to the EPANET 2 model, however, are not total consumption data, but a component or fractional part of total consumption at each pipeline junction or node of the pipeline network7. Each pipeline node represents a demand point within the pipeline network8. The sum of the component demands applied at each pipeline node for each of the 420 months of the historical period equals the total production for that month. A total of 2,272 nodes were used to represent the pipeline network in 1962 (Table A-1). By 1996, the number of nodes needed to represent the pipeline network had increased to 14,965 (Table A-35). A unique feature of the historical reconstruction analysis is the methods and approaches developed to spatially distribute a component of total monthly production to these nodes9. These methods and approaches are described in the following pages.
Data for historical consumption necessary for simulation consisted of two components梞onthly volumes (quantity) and spatial distribution (location). Metered consumption data (quantity and location), obtained from the water utility, were available solely for the presentday (1998) water-distribution system on a quarterly basis for October 1997 through April 1998 (Maslia et al. 2000a, p. 34). Details of the allocation of 1997� metered consumption to model nodes are described in the aforementioned report. The spatial distribution of demand at pipeline junctions for the 1998 pipeline network is shown on Plate 7 of Maslia et al. (2000a). Values of metered consumption for the 1998 water-distribution system assigned to individual nodes ranged from 0.001 gpm to about 9.0 gpm with a mean of about 0.4 gpm. To complete the historical reconstruction analysis, the demand at each node for each of the 420 months of the historical period (1962�) was required. With the exception of the present-day (1998) system, metered data or any other type of demand-point consumption were unavailable. Therefore, some method of estimating both the volume and the spatial distribution of consumption for each historical pipeline network on a monthly basis was required.
Estimation of Historical Consumption
A hypothetical present-day distribution-system network is shown in Figure 15. The total production or supply to the system (QP) is known, and data describing total consumption and its allocation throughout the distribution-system network (point-demand values at pipeline nodes) are available from billing records and field observations. That total production must equal total consumption is also a requirement of the water-distribution system and, for this example, is assigned at a rate of 10gpm. Therefore, the following conditions must apply:
where:
QP = total well production (obtained from well production data), in gallons per minute,
qi = demand at node i (estimated from metered billing records), in gallons per minute,
Qd = total of nodal (customer) demand, in gallons per minute,
NNP = total number of demand nodes in the present-day network.
A hypothetical historical distribution-system network (Network (A)) is shown in Figure 16. A comparison of the historical Network (A) with the present-day network (Figures 15 and 16) indicates that the historical network has fewer pipelines and nodes than the presentday network. Total production (QP) for the historical Network (A) is known and is assigned at 7.5 gpm (Figure 16). Accordingly, total production, and thus total demand for the historical network, are known. What must be estimated are the demand-point values at the historical network nodes. In Figure 16, the top number at each of the nodes is the present-day point demand (compare Figure 16 with Figure 15). Note, that the sum of the present-day demand values using the remaining nodes of historical Network (A) is 8.2 gpm (top numbers in Figure 16). To estimate the historical demand (bottom numbers at the nodes in Figure 16) consider the following:
where:
QPA = well production for historical Network (A), in gallons per minute, and
NNA = total number of demand nodes in historical Network (A).
However, the sum of the nodal demands (QD) for historical Network (A) must equal the production (QPA) for Network (A). Therefore, the present-day nodal demands (top numbers in Figure 16) are reduced in value by the ratio of the historical Network (A) production to the remaining present-day nodal demands (QPA / QD = 7.5/8.2), or:
where:
qiA = historical demand at node i for Network (A) in gallons per minute, and
QDA = total historical nodal (customer) demand for Network (A), in gallons per minute.
The estimated nodal values of demand for historical Network (A) are shown in Figure 16 (bottom numbers at each node). The sum of all point demands at these nodes is now equal to the historical production of 7.5 gpm. It should be noted, that because of numerical rounding, some minor adjustments were made to individual nodal values after multiplying by the ratio of (7.5/8.2) so that the sum of all the nodal demand values exactly equaled the production of 7.5 gpm.
An alternative historical distribution-system network, hypothetical Network (B) is shown in Figure 17, which, for these purposes, is assumed to have existed prior to historical Network (A). Comparison of historical Network (B) with historical Network (A) (Figures 17 and 16, respectively) indicates that Network (B) contains fewer pipelines and fewer nodes than Network (A). To estimate the consumption, the same procedure described previously is applied, except that historical Network (B) is used. Note that in the estimation procedure, for each historical network (whether hypothetical or actual), the initial demand values at the nodes (prior to modification) are always the ones associated with the present-day system (Figure 15). This condition is applied because present-day demands were the only available measured (or metered) demand values. Applying the demand estimation procedure described previously to Network (B), the total well production (QP) is assigned as 5.0 gpm. In Figure 17, the top number at each of the nodes is the original hypothetical present day nodal demand (Figure 15). Note, that the sum of the present-day demand values using the remaining nodes of historical Network (B) is 6.4 gpm (top numbers at the nodes in Figure 17). To estimate the historical demand (bottom numbers at the nodes in Figure 17) consider the following:
where:
QPB = well production for Network (B), in gallons per minute, and
NNB = total number of demand nodes in historical Network (B).
However, the sum of the nodal demands (QD) for historical Network (B) must equal the well production (QPB) for Network (B). Therefore, the present-day nodal demands (top numbers in Figure 17) are reduced in value by the ratio of the historical production to the remaining present-day nodal demands (QPB / QD = 5.0/6.4), or:
where:
qiB = historical demand at node i for Network (B) in gallons per minute, and
QDB = historical nodal (customer) demand for Network (B), in gallons per minute.
The revised nodal values of demand for Network (B) are the bottom numbers at each node, shown in Figure 17. The sum of these nodes is now equal to the historical production of 5.0 gpm. Because of numerical rounding, some minor adjustments were made to individual nodal values after multiplying by the ratio of (5.0/6.4) so that the sum of all the nodal demand values exactly equaled the production of 5.0 gpm. The estimation procedure described above and exemplified using Network (A) and Network (B) was applied to each historical distribution-system network for the Dover Township area (Plates 3�) to derive demand-point values of consumption at pipeline nodes for each of the 420 months of the historical period (1962�).
Distribution of Historical Consumption
The procedure for estimating the nodal distribution of consumption presented above assures that flow balance is preserved (that is, input equals output or total groundwater-well production equals total customer demand). However, underlying this method is the critical assumption that the spatial distribution of nodal demand for any historical pipeline network will be proportional to, if not the same as, the distribution of demand for the present-day (1998) network. Such an assumption does not account for changes in land-use patterns during the historical period. Accordingly, if a certain area of town in 1998 was designated residential in terms of water demand, and if that area of town was serviced by the historical water-distribution system, would the historical pattern also have been residential, or would the historical demand for water have been characterized by a different land-use pattern, such as industrial or rural? As previously discussed, the historical distribution of consumption was unknown. Therefore, an additional analysis was required to establish the validity of the assumption that land-use patterns, and thus demand for water for a particular area or for a particular group of pipeline nodes, did not change significantly over time in the Dover Township area.
A review of land-use classification and related land-use data is a reasonable method of classifying water-demand patterns over time. If land-use classification for a particular area changed historically (for example, from residential to industrial), then the water demand and the distribution of water demand would probably reflect that change. Historical land-use classification and zoning maps for Dover Township were readily available for the period 1957 to 1999.
A search for land-use classification and zoning maps by the staff of Eastern Research Group, Inc. (Leonard Young, written communication, March 21 and April 23, 2001) resulted in ATSDR obtaining land-use classification and zoning maps for Dover Township for the following years: 1957, 1967, 1978, 1990, and 1999. These land-use classification and zoning maps were specifically for Dover Township proper and did not include areas outside of Dover Township serviced by the water utility (for example, areas of Berkeley Township and the Borough of South Toms River; see Plate 2). However, because the areas outside of Dover Township proper serviced by the water utility constitute a relatively small percentage of the overall pipeline network, omitting these areas from consideration (owing to lack of data) did not compromise the analysis.
A total of eight classifications of land-use or zoning types that historically characterized Dover Township were portrayed on the specified maps: (1) central business district; (2) highway business; (3) hospital-medical service; (4) industrial; (5) office; (6) planned retirement community; (7) residential; and (8) rural (Table 3; Plates 46�). In order to determine land use for each positive-demand node during the historical period, a land-use classification associated with a particular land-use map was assigned to each demand node based on its location along the pipeline network. Once this was accomplished, a comparative analysis was conducted between the present-day (1998) system (for which both metered consumption and land-use classification data were available) and the historical pipeline networks to determine if the land-use classification at demand nodes during the historical period remained consistent or changed significantly. The pipeline networks and land-use classification and zoning map associations used in this analysis are listed below:
The association between pipeline nodes and land-use classification could be firmly established for 1998 conditions and, thus, provided a present-day condition to which the other historical pipeline networks and related land-use map classifications were compared.
The land-use maps were digitized in order to create databases suitable for analyses using a geographic information system (GIS). Using these digital databases, land-use and zoning classifications were assigned to specific polygons or areas of land in Dover Township using the GIS. For each year that land-use classification and zoning maps were available, a spatial digital database of demand nodes and related land-use classifications was created. A spatial analysis technique known as a "spatial join"10 was then applied to each database to assign all pipeline nodes a specific land-use classification. In the spatial join operation, any positive-demand node that fell completely within a particular land-use classification area, or polygon, was assigned the polygon抯 land-use classification attribute. This procedure was used for each of the land-use and associated pipeline networks described above. Results of this part of the analysis are presented as a series of maps (Plates 46�) that show the areal distribution of land-use classification assigned to pipeline nodes for the years 1998, 1990, 1978, 1967, and 1962, respectively. Each positive demand node displayed on the maps is assigned a color based on one of the eight previously specified land-use classifications. The three predominate land-use classifications that consistently appear are "Residential," "Planned Retirement Community," and "Highway Business." A qualitative assessment Plates 46 through 51 indicates that the spatial distribution of land use is highly consistent or nearly consistent throughout the historical period. To quantify this observation, a comparative analysis was undertaken using the positive-demand nodes displayed on Plates 46 through 51.
To conduct the comparative analysis, the total number of positive-demand nodes in the 1998 network within the boundaries of Dover Township was determined and demand statistics were computed (total, maximum, and minimum). Results of this analysis are presented in Table 3. Next, through the use of the GIS querying function, the number of positive-demand nodes and demand statistics for each of the eight land-use classifications was determined for the 1998 distribution-system network. In Table 3, the sum of the nodes (in the "Number of nodes" row) for all land-use classifications equals the number of nodes listed under the "Total Network" heading, and the sum of demand (in the "Total demand, gpm" row) for all land-use classifications equals the demand under the "Total Network" heading.
where:
%LUi, 98 = the percentage of positive-demand nodes for the ith land-use classification in 1998 (1 = 1, ..., 8),
NLUi, 98 = the total number of positive-demand nodes for the ith land-use classification, in 1998, and
NN98 = total number of positive-demand nodes in the 1998 pipeline network that occurred within the boundaries of Dover Township.
Values in the "Percent demand" row for the 1998 network were computed using the following formula:
where:
%Di,98 = the percentage of positive-demand nodes for the ith land-use classification in 1998 (1 = 1, ..., 8),
DLUi, 98 = demand, in gallons per minute, for nodes assigned the ith land-use classification, summed for the total number of positive-demand nodes (j = 1, ..., Ni,98) in the ith land-use classification in 1998,
D98 = demand, in gallons per minute, in the 1998 pipeline network summed for the total number of positive-demand nodes (NN98) that occurred within the boundaries of Dover Township, and
Ni,98 = the total number of positive-demand nodes assigned the ith land-use classification in 1998 that occurred within the boundaries of Dover Township.
The values in the "Percent nodes" and the "Percent demand" rows thus computed for the 1998 pipeline network, were used as the basis for comparison when similar computations were applied to specified historical networks. Note, that these values and the related percentages refer only to that portion of the 1998 network that existed within the political boundaries of Dover Township.
In Table 3, nodes assigned a land-use classification of "Residential" in 1998 account for 80% of the positive-demand nodes and 82% of the total demand; nodes assigned a land-use classification of "Planned Retirement Community" account for about 9% of the positive-demand nodes and about 8% of total demand; nodes assigned a land-use classification of "Highway-Business" account for about 5% of the positive-demand nodes and about 5% of total demand. Thus, three land-use classifications account for about 94% of the positive-demand nodes assigned to the 1998 pipeline network and about 95% of the total network demand. This finding is consistent with observations from Plate 46 that portray the areal distribution of positive-demand nodes for the 1998 water-distribution system.
Table 3. Land-use classification analysis for present-day (1998) and historical pipeline networks, Dover Township, New Jersey1
[gpm, gallons per minute; � not applicable]
|
Network Total |
Central Business District |
Highway Business |
Hospital-Medical Service |
Industrial |
Office |
Planned Retirement Community |
Residential |
Rural |
|---|---|---|---|---|---|---|---|---|---|
|
|||||||||
1998 (Present-Day) Network2 |
|||||||||
Number of nodes3 |
9,595 |
27 |
505 |
4 |
63 |
144 |
838 |
7,697 |
317 |
Total demand, gpm |
4,048.0 |
8.7 |
190.2 |
0.5 |
22.1 |
53.5 |
311.8 |
3,319.0 |
142.3 |
Maximum demand, gpm |
9.0 |
1.2 |
9.0 |
0.2 |
1.2 |
3.2 |
1.6 |
6.1 |
6.0 |
Minimum demand, gpm |
0.001 |
0.01 |
0.003 |
0.02 |
0.004 |
0.01 |
0.01 |
0.001 |
0.01 |
Percent nodes4 |
�/p> |
0.3 |
5.3 |
0.0 |
0.7 |
1.5 |
8.7 |
80.2 |
3.3 |
Percent demand5 |
�/p> |
0.2 |
4.7 |
0.0 |
0.6 |
1.3 |
7.7 |
82.0 |
3.5 |
1996 Network6 |
|||||||||
Number of nodes3 |
9,582 |
27 |
505 |
4 |
63 |
144 |
826 |
7,696 |
317 |
Total demand, gpm |
4,042.2 |
8.7 |
190.2 |
0.5 |
22.1 |
53.5 |
307.0 |
3,317.9 |
142.3 |
Maximum demand, gpm |
9.0 |
1.2 |
9.0 |
0.2 |
1.2 |
3.2 |
1.6 |
6.1 |
6.0 |
Minimum demand, gpm |
0.001 |
0.01 |
0.003 |
0.02 |
0.01 |
0.01 |
0.01 |
0.001 |
0.01 |
Percent nodes7 |
99.9 |
0.3 |
5.3 |
0.0 |
0.7 |
1.5 |
8.6 |
80.3 |
3.3 |
Percent demand8 |
99.9 |
0.2 |
1.4 |
0.0 |
0.6 |
1.3 |
7.6 |
82.1 |
3.5 |
1990 Network9 |
|||||||||
Number of nodes3 |
8,619 |
26 |
476 |
4 |
56 |
145 |
535 |
7,089 |
288 |
Total demand, gpm |
3,714.6 |
8.6 |
164.7 |
0.5 |
18.3 |
61.7 |
219.0 |
3,107.3 |
134.4 |
Maximum demand, gpm |
6.1 |
1.2 |
5.8 |
0.2 |
1.5 |
4.1 |
1.6 |
6.1 |
0.01 |
Minimum demand, gpm |
0.001 |
0.01 |
0.003 |
0.02 |
0.002 |
0.01 |
0.2 |
0.001 |
0.01 |
Percent nodes7 |
89.8 |
0.3 |
5.5 |
0.1 |
0.7 |
1.7 |
6.2 |
82.3 |
3.3 |
Percent demand8 |
91.8 |
0.2 |
4.4 |
0.0 |
0.5 |
1.7 |
5.9 |
83.7 |
3.6 |
1978 Network10 |
|||||||||
Number of nodes3 |
5,928 |
105 |
297 |
7 |
82 |
88 |
370 |
4,933 |
52 |
Total demand, gpm |
2,512.8 |
49.5 |
89.2 |
2.7 |
29.7 |
49.2 |
145.3 |
2,099.8 |
47.4 |
Maximum demand, gpm |
6.1 |
1.7 |
3.7 |
1.1 |
1.5 |
6.1 |
1.5 |
3.1 |
6.0 |
Minimum demand, gpm |
0.003 |
0.2 |
0.01 |
0.02 |
0.1 |
0.9 |
0.1 |
0.1 |
1.5 |
Percent nodes7 |
61.8 |
1.8 |
4.9 |
0.1 |
1.4 |
1.5 |
6.2 |
83.2 |
0.9 |
Percent demand8 |
62.1 |
2.0 |
3.6 |
0.1 |
1.2 |
2.0 |
5.8 |
83.6 |
1.9 |
1967 Network11 |
|||||||||
Number of nodes3 |
3,169 |
92 |
172 |
�sup>12 |
52 |
�sup>12 |
209 |
2,612 |
27 |
Total demand, gpm |
1,346.5 |
38.8 |
52.8 |
�sup>12 |
22.6 |
�sup>12 |
86.9 |
1,132.6 |
12.8 |
Maximum demand, gpm |
3.7 |
1.7 |
3.7 |
�sup>12 |
1.6 |
�sup>12 |
1.5 |
3.0 |
1.2 |
Minimum demand, gpm |
0.003 |
0.1 |
0.003 |
�sup>12 |
0.01 |
�sup>12 |
0.02 |
0.01 |
0.1 |
Percent nodes7 |
33.3 |
3.1 |
5.4 |
�sup>12 |
1.6 |
�sup>12 |
6.6 |
82.4 |
0.9 |
Percent demand8 |
33.3 |
2.9 |
3.9 |
�sup>12 |
1.7 |
�sup>12 |
6.5 |
84.1 |
1.0 |
1962 Network13 |
|||||||||
Number of nodes3 |
1,688 |
65 |
102 |
�sup>12 |
115 |
10 |
�sup>12 |
1,396 |
�sup>12 |
Total demand, gpm |
711.9 |
27.0 |
29.4 |
�sup>12 |
50.6 |
4.2 |
�sup>12 |
600.7 |
�sup>12 |
Maximum demand, gpm |
2.9 |
1.7 |
2.2 |
�sup>12 |
0.4 |
0.9 |
�sup>12 |
2.9 |
�sup>12 |
Minimum demand, gpm |
0.01 |
0.01 |
0.01 |
�sup>12 |
0.01 |
0.03 |
�sup>12 |
0.01 |
�sup>12 |
Percent nodes7 |
17.6 |
3.9 |
6.0 |
�sup>12 |
6.8 |
0.6 |
�sup>12 |
82.7 |
�sup>12 |
Percent demand8 |
17.6 |
3.8 |
4.1 |
�sup>12 |
7.1 |
0.6 |
�sup>12 |
84.4 |
�sup>12 |
|
1Does not include Berkeley Township and Borough of South Toms River areas serviced by water utility. |
|||||||||
The next step in the comparative analysis was to repeat the computations described above using the digital land-use classification and related demand-node databases for the historical networks (1996, 1990, 1978, 1967, and 1962). For these networks, and for the related entries in Table 3, the "Percent nodes" and "Percent demand" values in the "Total Network" column were computed relative to the number of positive-demand nodes and the related demand computed for each land-use classification for the 1998 pipeline network. For example (Table 3):
For each of the land-use classification columns and for each historical pipeline network listed in Table 3, the "Percent nodes" and "Percent demand" were computed using the following formulas:
where:
%LUi,j = percentage of positive-demand nodes for the ith land-use classification and for the jth historical network, (1 = 1, ..., 8; j = 1996, 1990, 1978, 1967, 1962),
NLUi,j = total number of positive-demand nodes for ith land-use classification and for the jth historical network,
NNj = total number of positive-demand nodes in the jth historical pipeline network that occurred within the boundaries of Dover Township.
"Percent demand":
where:
%Di,j = the percentage of positive-demand nodes for the ith land-use classification and the jth historical network, (1 = 1, ..., 8; j = 1996, 1990, 1978, 1967, 1962),
DLUi,j = demand, in gallons per minute, for nodes assigned the ith land-use classification for the jth historical network, summed for the total number of positive-demand nodes in the ith land-use classification for the jth historical network (NNi,j)
Dj = demand, in gallons per minute, in the jth historical pipeline network summed for the total number of positive-demand nodes (NNj) that occurred within the boundaries of Dover Township, and
NNi,j = the total number of positive demand nodes assigned the ith land-use classificiation for the jth historical pipeline network that occurred within the boundaries of Dover Township.
The results of these computations for the historical pipeline networks are summarized in Table 3. For the "Residential" land-use classification, the "Percent nodes" ranges between 80% and 83% for all historical networks, and the corresponding "Percent demand" ranges between 82% and 84%. The "Percent nodes" and "Percent demand" for the "Planned Retirement" land-use classification range between about 6% and 9% for all historical networks. (This land-use classification is not present for the earliest historical network, 1962.) For the "Highway Business" land-use classification, the "Percent nodes" and "Percent demand" range between about 4% and 6% for all historical networks. Note that the "Industrial" and "Central Business District" land-use classifications, that potentially could have significantly altered the historical distribution of demand, comprise an insignificant part of the overall historical demand distribution both in terms of the number of pipeline nodes and the magnitude of demand. Thus, the major land-use classification types, "Residential," "Highway Business," and "Planned Retirement Community," have historically and consistently constituted approximately 90% or more of positive-demand nodes and total system-wide demand based on those nodes located within the boundaries of Dover Township. Note, because of similar water-use practices, the "Planned Retirement Community" land-use classification could have reasonably been combined with the "Residential" land-use classification, rather than considered as a distinct classification.
As stated above, the land-use classification analysis was not conducted for areas serviced by the water utility that were outside the Dover Township boundary (portions of Berkeley Township and the Borough of South Toms River) because land-use classification and zoning maps were not available for these areas. Historically, these areas have been residential in their land use, being primarily used for single family residences such as retirement (adult) communities. Therefore, had land-use classification and zoning maps been available to investigators, pipeline demand nodes located in these areas also would have been assigned a "Residential" or "Planned Retirement Community" land-use classification.
This land-use classification analysis has established that the 1998 distribution of demand梑ased on land-use classification that is spatially consistent through time梙istorically, is probably a good estimator for the spatial distribution of demand. Based on these results, monthly databases of demand quantity (volume) and demand distribution (location) were developed for the entire historical reconstruction analysis period, 1962�.
HIGH-SERVICE AND BOOSTER PUMP CHARACTERISTIC CURVES
High-service and booster pumps are used to raise the hydraulic head of water and increase the pressure in certain parts of the water-distribution system. The representation of these pumps in EPANET 2 is described in the Users Manual and requires data derived from pumpcharacteristic curves. Characteristic curves specific to the water-distribution system serving the Dover Township area were derived from data supplied by the water utility and from model calibration, and are described in detail in Maslia et al. (2000a). Pump-characteristic curve data in Maslia et al. (2000a) are provided in both tabular and graphical format. The reader is referred to these aforementioned reports for additional details. In a subsequent section of this report, ("Methods of Analysis and Approach to Simulation"), the representation of high-service and booster pumps in the historical waterdistribution system networks is described in the context of model design and simulations.
To simulate the distribution of water for each of the 420 months of the historical period, information regarding the on-and-off cycling of wells and high-service and booster pumps is required. This operations information is input to the EPANET 2 program in the form of "Pattern" and "Pump Control" data (Rossman 2000; Maslia et al. 2000a, pp. 38-41). Prior to 1978, operational data were unavailable and thus, an alternative approach was required to determine system-operation parameters. The approach selected for this study was the development of "Master Operating Criteria" (Table 4).
Table 4. "Master Operating Criteria" used to develop operating schedules for the historical water-distribution system, Dover Township area, New Jersey
Parameter |
Criteria |
|---|---|
Pressure1 |
Minimum of 15 pounds per square inch, maximum of 110 pounds per square inch at pipeline locations, including network end points |
Water level |
Minimum of 3 feet above bottom elevation of tank; maximum equal to elevation of top of tank; ending water level should equal the starting water level |
Hydraulic device online date |
June 1 of year installed to meet maximum-demand conditions |
On-and-off cycling: Manual operation |
Wells and high-service and booster pumps cannot be cycled on-and-off from 2200 to 0600 hours |
On-and-off cycling: Automatic operation |
Wells and high-service and booster pumps can be cycled on-and-off at any hour |
Operating hours |
Wells should be operated continuously for the total number of production hours, based on production data2 |
|
1Generally, for residential demand, minimum recommended pressure is about 20 pounds per square inch. However, for some locations in the Dover Township area (mostly in areas near the end of distribution lines) lower pressures were simulated. |
|
The "Master Operating Criteria" are explicit conditions and standards based on hydraulic engineering principles necessary to successfully operate water-distribution systems similar to the one serving the Dover Township area. From 1978 forward, for selected years, operators of the water utility provided information describing generalized operating practices for a typical "peak-demand" (summer) and "non-peak demand" (fall) day. These guidelines were used in conjunction with the "Master Operating Criteria" to simulate a "typical" 24-hour daily operation of the water-distribution system. Prior to 1978, however, only the "Master Operating Criteria" were used to simulate system operations.
Using the "Master Operating Criteria" (Table 4) as guidelines, a 24-hour operating schedule was developed for each month of the historical period. Daily operational variations including routine maintenance of system facilities, repair of pipeline breaks, emergency fire service, and other temporary interruptions of routine operations over a "typical" 24-hour period were considered insignificant using this approach. Thus, the daily system operating schedule was assumed to be representative of a "typical" 24-hour day for the month11. A list of monthly operating schedules, with details for the selected years of 1962, 1965, 1971, 1978, 1988, and 1996, is provided in tabular form in Appendix C (Tables C-1 through C-7). Information contained in these tables includes initial water levels in storage tanks, the hours of operation of wells and high-service and booster pumps, the flow rate at which wells and high-service and booster pumps were operated, and operational notes indicating when wells were taken out of service by the water utility.
A graphical representation of the on-and-off cycling of wells and high-service and booster pumps for the minimum-demand, maximum-demand, and average-demand months for the aforementioned selected years is presented in Appendix D (Tables D-1 through D-21). The information in Appendices C and D was developed using available data (Board of Public Utilities, State of New Jersey 1962�96), the "Master Operating Criteria", water-utility information (Flegal 1997 and Richard Ottens, Jr., Production Manager, United Water Toms River, Inc., written communication, 1998), and simulation results. Examples of historical water-distribution system operating schedules for the maximum-demand months of May 1962, July 1971, July 1988, and June 1996梩aken from the tables in Appendix D梐re shown in Tables 5 through 8, respectively. These tables indicate the hour-by-hour operation of wells and high-service and booster pumps during a typical day of the maximum-demand month for the given year. Note, that in 1962 (Table 5), high-service and booster pumps were not part of the distribution system and, therefore, only groundwater wells were operated to supply demand by discharging water directly into the distribution system (wells 13�, Figure 8). In 1968, high-service and booster pumps were added to the distribution system (see section on "High-Service and Booster Pumps"). From that year forward, some wells supplied storage tanks, then high-service and booster pumps were operated to meet distribution-system demands (wells 21�, 40, and 42; Figure 5); while other wells continued to discharge directly into the distribution system (refer to Tables 5 through 8 for details).
The operating schedule for the earliest of the historical networks is relatively simple (for example, 1962, Table 5). However, by the latter years of the historical period (for example, 1988, Table 7), the operating schedules became increasingly complex owing to the number of hydraulic devices that are cycled on-and-off. Information presented in Tables 5 through 8 and in Appendix D demonstrate the increasing complexity of system operating schedules. These tables are divided into 24, one-hour time increments representing the 24 hours of a day (hour 0 is midnight and hour 12 is noon). Furthermore, the tables in Appendix D (D-1 through D-21) show the operating schedule for the three annual demand periods (minimum, maximum, and average). In 1962, the Brookside well (15; see Figure 5 or Plate 3 for location) was the primary well used for supplying the water-distribution system, as the well was operated for 19 hours on a typical day during the maximum-demand month of May (Table 5). By comparison, in 1988 (Table 7), to meet demand, four wells had to be operated for 20 or more hours each day. The Indian Head well (20, see Figure 7 or Plate 29 for location) was operated for 20 hours on a typical day during the maximum-demand month of July 1988, the Route 70 well (31) was operated for 22 hours, and the Berkeley wells (33 and 34) were operated for 24 and 23 hours, respectively. Also of note in Tables 5 and 7, all wells are shown to operate continuously to meet the number of operating hours required, as was described above in the list of "Master Operating Criteria" (Table 4). The operating schedules for the groundwater wells (Tables 5� can also be compared with the production data presented in Appendix B (Tables B-1, B-10, B-27, and B-35, respectively). For example, for groundwater wells that discharged directly into the distribution system during July 1971, Table 6 shows an operating schedule of:
These are the same number of production hours shown for these wells in Table B-10. For the more complex network, during June 1996, for groundwater wells that discharged directly into the distribution system, Table 8 shows an operating schedule of:
These are the same number of production hours shown in Table B-35 for all wells except South Toms River well 38. In June 1996, well 38 should have been operated for 13 hours (Table B-35). However, in order to successfully operate the system in June 1996 (preserve a balanced flow condition and meet the "Master Operating Criteria"桾able 4), the number of hours of required operation for well 38 had to be modified from the initial estimate of 13 hours to 10 hours. In this situation, however, the total production of about 12.5 Mgal listed in Table B-35 for South Toms River well 38 was preserved for simulation purposes. Thus, in developing the operating schedules listed in Appendix C, investigators honored the "Master Operating Criteria" (Table 4), the production-data volumes, and in most situations, the production-data hours of operation based on reported well capacity and total production (Appendix B).
High-Service and Booster Pumps
Data in Tables 6 through 8, and Tables in Appendix C and D, show the operating schedules of high-service and booster pumps. The specific date that high-service and booster pumps were first introduced into the water-distribution system is unknown and could not be verified by the current operators of the water utility. However, information found in the annual reports of the Board of Public Utilities, State of New Jersey (1962�96) indicate that Holly pumps 1, 2, and 3 were first used sometime during 1968. A listing of all high-service and booster pumps supplying the water-distribution system during the historical period is provided in Table 9. High-service and booster pump discharge data reported by the water utility are limited. In addition, with the exception of Windsor pumps 1, 2, and 3, significant differences occurred between the estimated discharge reported by the water utility and the rated pump capacity values reported in the annual reports of the Board of Public Utilities, State of New Jersey (1962�96). To account and reconcile these inconsistencies, the generalized "peak day" (summer) and "non-peak day" (fall) operating notes obtained from the water utility were used as initial estimates for determining the operating schedules of the high-service and booster pumps.
The pump discharge information obtained from the water utility is listed in Table 9 in the shaded areas (Richard Ottens, Jr., Production Manager, United Water Toms River, Inc., written communication, 1998). Based on this information (Table 9) and simulation, operating schedules for the high-service and booster pumps shown in Tables 6 through 8, and in tables of Appendices C and D, were developed to simulate the operation of the historical water-distribution system. Additional discussion of the simulation of high-service and booster pump discharge to the water-distribution system using EPANET 2 is provided in the "Methods of Analysis and Approaches to Simulation" section of this report.
Table 9. High-service and booster pump data, Dover Township area, New Jersey, 1962-96
[�, pump not installed, no rated capacity or estimated discharge data available; Estimated discharge data from Richard Ottens, Jr., Production Manager, United Water Toms River, Inc., 1998; values represent typical peak-day (summer) or non-peak day (fall)]
Year |
Pump Identification1 and Rated Capacity or Estimated Discharge, in gallons per minute |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Holly Pump 1 |
Holly Pump 2 |
Holly Pump 3 |
Parkway Pump 1 |
Parkway Pump 2 |
Holiday City Pump |
St. Catherine's (Route 37) Pump |
South Toms River Pump 1 |
South Toms River Pump 2 |
Windsor Pump 1 |
Windsor Pump 2 |
Windsor Pump 3 |
1962 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1963 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1964 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1965 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
|
||||||||||||
1966 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1967 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1968 |
2800 |
1,500 |
3,200 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1969 |
800 |
1,500 |
3,200 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1970 |
800 |
1,500 |
3,200 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
|
||||||||||||
1971 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1972 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1973 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1974 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1975 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
1,400 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
|
||||||||||||
1976 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
1,400 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1977 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
1,400 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1978 |
800 |
1,500 |
3,200 |
3,000 |
4,800 |
500 |
500 |
�/p> |
�/p> |
�/p> |
�/p> |
�/p> |
1979 |
800 |
1,500 |
3,200 |
3,000 |
4,800 |
500 |
500 |
500 |
500 |
�/p> |
�/p> |
�/p> |
1980 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
1,400 |
1,400 |
500 |
500 |
�/p> |
�/p> |
�/p> |
|
||||||||||||
1981 |
800 |
1,500 |
3,200 |
3,000 |
4,800 |
500 |
500 |
500 |
5000 |
�/p> |
�/p> |
�/p> |
1982 |
800 |
1,500 |
3,200 |
5,500 |
4,800 |
500 |
500 |
500 |
500 |
1,000 |
1,000 |
�/p> |
1983 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
1,400 |
1,400 |
500 |
500 |
1,000 |
1,000 |
�/p> |
1984 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
1,400 |
1,400 |
500 |
500 |
1,000 |
1,000 |
�/p> |
1985 |
800 |
1,500 |
3,200 |
5,500 |
2,400 |
1,400 |
1,400 |
500 |
500 |
1,000 |
1,000 |
�/p> |
|
||||||||||||
1986 |
800 |
1,500 |
3,200 |
3,000 |
4,000 |
500 |
500 |
500 |
500 |
1,000 |
1,000 |
�/p> |
1987 |
800 |
1,500 |
3,200 |
3,000 |
4,000 |
500 |
500 |
500 |
500 |
1,000 |
1,000 |
�/p> |
1988 |
800 |
1,500 |
3,200 |
3,000 |
4,000 |
500 |
500 |
500 |
500 |
1,000 |
1,000 |
�/p> |
1989 |
800 |
1,500 |
3,600 |
3,000 |
4,000 |
500 |
1,400 |
500 |
500 |
1,000 |
1,000 |
�/p> |
1990 |
800 |
1,500 |
3,200 |
5,500 |
4,000 |
800 |
650 |
500 |
500 |
1,000 |
1,000 |
1,000 |
|
||||||||||||
1991 |
800 |
1,500 |
3,200 |
2,400 |
5,500 |
1,400 |
650 |
500 |
500 |
1,000 |
1,000 |
1,000 |
1992 |
800 |
1,500 |
3,200 |
2,400 |
5,500 |
1,400 |
650 |
500 |
500 |
1,000 |
1,000 |
1,000 |
1993 |
800 |
1,500 |
3,200 |
2,400 |
5,500 |
800 |
800 |
500 |
500 |
1,000 |
1,000 |
1,000 |
1994 |
800 |
1,500 |
3,200 |
3,200 |
4,800 |
800 |
800 |
500 |
500 |
1,000 |
1,000 |
1,000 |
1995 |
800 |
1,500 |
3,200 |
3,200 |
5,500 |
1,400 |
650 |
500 |
500 |
1,000 |
1,000 |
1,000 |
|
||||||||||||
1996 |
800 |
1,500 |
3,200 |
3,200 |
5,500 |
1,400 |
650 |
500 |
500 |
1,000 |
1,000 |
1,000 |
|
1Pump Identification�span class="italic">High-service pumps: Holly pump 1, Holly pump 2, and Holly pump 3; Parkway pump 1 and Parkway pump 2; Windsor pump 1, Windsor pump 2, and Windsor pump 3. Booster pumps: Holiday City; St. Catherine抯 (Route 37); South Toms River pump 1, and South Toms River pump 2. |
||||||||||||
STORAGE-TANK AND WATER-LEVEL DATA
Storage-tank data required for input into EPANET 2 are tank capacities in the form of tank diameter and the minimum and maximum allowable water level. For the historical reconstruction analysis, all storage tanks were assumed of cylindrical geometry. All relevant data on storage tanks in use by the water-distribution system during the historical period of 1962� are listed in Table 10. With the exception of the Horner Street tank and standpipe, which were taken out of service in June 1963 (Table 10 and Figure 18; see Plate 3 for location), all storage tanks operating in the present-day system were brought on-line during the historical period. As previously discussed, for simulation purposes, hydraulic devices such as storage tanks were brought into service on June 1 of the specified year in order to meet demand during the peak (summer) season. The storage capacity of the historical water-distribution system, shown graphically in Figure 10, grew from 0.3 Mgal in 1963 (after removing the Horner Street tank and standpipe from service), to 7.35 Mgal in 1992 with the addition of the North Dover elevated storage tank (see Figure 8 or Plate 33 for location). The capacity of the system at the end of the historical analysis period (1996) and for the present-day system (1998) remains at 7.35 Mgal. As indicated in Table 10, the minimum allowable water level in the tanks (for the purposes of simulating historical conditions) was set at the bottom elevation of the tank plus 3 feet, and the maximum allowable water level was set at the elevation of the top of the tank. This method of storage tank operation is in agreement with the "Master Operating Criteria" (Table 4) previously discussed. A graphical representation of the temporal distribution of storage capacity for the distribution system during the historical period (1962�) is presented in Figure 18.
Table 10. Storage-tank characterization data used for historical reconstruction analysis, Dover Township area, New Jersey, 1962-96
[Data from annual reports of the Board of Public Utilities, State of New Jersey (1962-96), unless otherwise noted]
Storage Tank Identification |
Type |
Diameter (feet) |
Height1 (feet) |
Volume (million gallons) |
Elevation of Tank Bottom (feet) |
Minimum Water-Level2 (feet) |
Maximum Water-Level (feet) |
Service Year |
|---|---|---|---|---|---|---|---|---|
Horner Street |
Elevated |
20 |
25 |
0.06 |
80 |
3 |
25 |
31898 |
Horner Street |
Standpipe |
25 |
105 |
0.39 |
32 |
3 |
105 |
31926 |
South Toms River |
Elevated |
43.3 |
28 |
0.30 |
166.0 |
3 |
28 |
1963 |
Indian Hill |
Elevated |
50 |
40 |
0.50 |
160.0 |
3 |
40 |
1967 |
Holly 1 |
Ground-level |
88 |
10 |
0.525 |
6.52 |
3 |
10 |
1968 |
Holly 2 |
Ground-level |
88 |
10 |
0.525 |
6.52 |
3 |
10 |
1968 |
Parkway |
Ground-level |
85 |
24 |
1.0 |
10.43 |
3 |
24 |
1971 |
Holiday City |
Ground-level |
82.5 |
24 |
1.0 |
87.12 |
3 |
24 |
1975 |
St. Catherine抯 (Route 37) |
Ground-level |
66 |
40 |
1.0 |
42.93 |
3 |
40 |
1978 |
Windsor |
Ground-level |
103 |
24 |
1.5 |
9.84 |
3 |
24 |
1982 |
North Dover |
Elevated |
65 |
51 |
1.0 |
170.0 |
3 |
51 |
1992 |
|
1Data from control room notes taken by ATSDR and NJDHSS staff, March 1998, except for Horner Street elevated-storage tank and standpipe. |
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In summary, the six specific data types and other information that were used to conduct the historical reconstruction analysis are described in detail along with appropriate limitations and qualifications. Table 11 summarizes the location of the specific data types and other information in this report or in Maslia et al. (2000a) to assist the reader in locating the data. Specifically, the required data types are: (1) pipeline or network configurations for the historical period (1962�), (2) potable water production data including information on the location, capacity, and time of operation of the groundwater wells producing the water, (3) estimates of historical consumption and the spatial distribution of point-demand values at pipeline nodes, (4) booster pump-characteristic curve data, (5) system operations information such as schedules that describe the on-and-off cycling of wells and high-service and booster pumps, and (6) data describing the capacity and operational extremes of storage-tanks.
Table 11. Summary of specific data types and other information used to conduct the historical reconstruction analyis, Dover Township area, New Jersey
Specific Data Type |
Location |
|---|---|
Network pipeline data |
Plates 3�; Figures 5�; Appendix A |
Groundwater well identification, location, and production data |
Figures 11�; Appendix B |
Consumption data for 1998 |
Maslia et al. (2000a, Plate 7) |
High-Service and Booster-pump data and characteristic curves |
Maslia et al. (2000a, Table 9 and Appendix F) |
System operation notes for selected years of 1962, 1965, 1971, 1978, 1988, 1995, and 1996 |
Appendix C |
Storage-tank characterization data |
Table 10 |
Other Information |
Location |
|---|---|
"Mastering Operating Criteria" for system operations |
Table 4 |
Graphical presentation of operating schedules for minimum-, maximum-, and average-demand months for selected years 1962, 1965, 1971, 1978, 1988, 1995, and 1996 |
Appendix D |
High-service and booster pump rated capacity and estimated-discharge data |
Table 9 |
