SANTA TERESA - Territory Stories: Home€¦ · Santa Teresa obtains its present groundwater supply...

Technical Report WRA89020

Viewed at 03:02:30 on 18/02/2010 of 41.

I I I I I I I I I I I I I I I I I I I I

POWER AND WATER AUTHORITY WATER DIRECTORATE

SANTA TERESA GROUNDWATER STUDY

1986

prepared by: G SALAS Water Resources Group

June 1987


Viewed at 03:02:30 on 18/02/2010 of 41.


SUMMARY

A groundwater study was carried out in a Tertiary sedimentary basin southeast of Alice Springs. The purpose of the study was to increase the existing water supply for Santa Teresa.

Work included drilling and geophysical surveying. The outcome was the construction of two new production bores capable of yielding 5 Lis each of potable groundwater.

Results of the study suggest the groundwater potential of the basin is much larger than previously estimated.


Viewed at 03:02:30 on 18/02/2010 of 41.


1.

2.

3.

4.

5.

6.

7.

8.

9.

TABLE OF CONTENTS

SUMMARY

INTRODUCTION

1.1 Background and Objective 1.2 Approach to the Study

ABSESSMENT OF AVAILABLE INFORMATION

2.1 Geology 2.2 Previous Investigations 2.3 Bore Data Review

WORK PROGRAMME

3.1 3.2 3.3

stage 1: Stage 2: Stage 3:

RESULTS

4.1 Stage 1: 4.1.1 4.1. 2

4.2 Stage 2: 4.3 stage 3:

4.3.1 4.3.2 4.3.3 4.3.4

Tertiary Base - Shannon Formation Drilling Geophysical Survey Further Drilling

Tertiary Base - Shannon Formation Drilling Bore RN 14418 Production Bore RN 14847 Geophysical Survey Further Drilling Bore RN 14848 Bot"e RN 14849 Bore RN 14850 Production bore RN 14851

WATER QUALITY RESULTS

PUMPING TESTS

CONCLUSIONS

RECOMMENDATIONS

8.1 Bore Management Recommendations 8.2 General Recommendations

REFERENCES

APPENDIX A

APPENDIX B

pumping Test Reports on Bores RN 14847 and RN 14851

Water Quality Data for Bores RN 14418, RN 14847 and RN 14851


Viewed at 03:02:30 on 18/02/2010 of 41.


1.

2.

ATTACHMENTS

LIST OF FIGURES

1 Borefield and Location Map

2 Santa Teresa Geology

3 Grain Size Distribution - Sample Returns RN 14848

4 Construction Details RN 14847

5 Construction Details RN 14851

A/1 Constant Discharge Test RN 14847

A/2 Step Drawdown Test RN 14847

A/3 Constant Discharge Test RN 14851

A/4 step Drawdown Test RN 14851

LIST OF TABLES

1 Bores Drilled in the Santa Teresa Area before 1986

2 Data on Bores Constructed at Santa Teresa (1986)

B/l water Quality Data RN 14418, 14847, 14851


Viewed at 03:02:30 on 18/02/2010 of 41.


-1-

1. INTRODUCTION

1.1 Background and Objective

Santa Teresa is an Aboriginal community of some 500 inhabitants located 80 km southeast of Alice Springs (Fig 1). Bstablished in a semi arid environment, with an average rainfall of less than 250 mm per annum and evaporation rates ten times higher, Santa Teresa extracts its water supply from a small borefield 5 km to the northeast.

The yield of the borefield was 15 litres per second (L/s) in 1979; but its output has gradually decreased to approximately 7 L/s at present, causing water shortage problems.

In 1985 the Department of Community Development assigned funds to water Resources Division (then Department of Mines and Bnergy) to carry out a drilling programme resulting in the construction of new production bores capable of increasing the existing water supply by 10 L/s.

The objective of this study was to meet this requirement.

1.2 Approach to the Study

An initial review of records of Santa Teresa's borefield indicated that often production bores had been initially sucessful at meeting required groundwater demands. However, in the long term some of these bores failed, as their yields decreased with use and water shortages re-occurred.

An inspection of bore strata samples and of cores of stratigraphic holes (Wyche, 1983) suggested that long term bore failures could have been caused, to some extent, by the grain size characteristics of the aquifers drilled (Section 2). It was then decided that the objective of this study would be achieved by adopting an exploration strategy, which would search for more stable aquifers beyond the boundaries established by previous groundwater work. For this purpose, extensive use would be made of all the upgraded geological and geophysical information that was or could be made available.

An assessment of geological and hydrogeological maps and reports followed, and a study of drilling data was made. All the information reviewed was summarized (Section 2). Additionally, aerial photographs were interpreted and geological field reconnaissances were carried out.

AS a result of this assessment, a work programme was structured (Section 3) and drilling targets were defined. Work proceeded accordingly (Section 4), completing progressive stages specified in the work programme.


Viewed at 03:02:30 on 18/02/2010 of 41.


-2-

2. ASSESSMENT OF AVAILABLE INFORMATION

2.1 Geology

Santa Teresa obtains its present groundwater supply from a sequence of interbedded clayey sand, sand, silt and clay of Tertiary age. These sediments seem to have been deposited under the influence of alternating fluvial and lacustrine environments (Wyche 1983), within a basin formed by the erosion of pre-Tertiary rocks. The basin is shown in Figure 2.

The Santa Teresa basin covers an area of approximately 100 km', and has an elliptical shape. Its longest axis extends for a distance of some 18 km in a north west - south east direction, approximately parallel to the main trend of the structural features affecting the surrounding rocks.

Outcrops of Cambrian Shannon Formation composed of interbedded siltstone, sandstone, limestone, shale and dolomite (Wells et al., 1970) almost completely surround the basin. The Shannon Formation is underlain by Giles Creek Dolomite, also of Cambrian age.

Faulting and folding affected the pre-Tertiary rocks. A number of north to northwest trending faults cut through the rocks cropping out to the north, east and south west of the basin (Figure 2). Some of these faults possibly continue underneath the basin and could have controlled the development of its shape (Wyche 1983). In the southeastern half of the basin, where this investigation was centered, the Tertiary sediments are contained within the limbs of a syncline defined by outcrops of Shannon Formation, Giles Creek Dolomite and older rocks.

2.2 previous Investigations

Ride (1967) carried out a groundwater investigation along Phillipson Creek, between the Santa Teresa airstrip and Phillipson Bore (RN 5006, Figure 2). Three electrical soundings were carried out and three holes drilled. Only one bore, RN 5777, found potable water, with a TDS content of 500 mg/L. TDS content of groundwater struck by bores RN 5776 (3799 mg/L) and RN 5775 (1880 mg/L) were too high for human consumption.

Ride interpreted his results as showing the presence of a buried valley extending under an area of 21 km' and infilled with sediments to a depth exceeding 60 m. He called this valtey the "Santa Teresa Basin" and estimated it contained 142 x 10 m3 of saturated sediments storing 4 x 10 6 m3 of groundwater. He· calculated the safe yield of the "basin" was 270 000 m3 per year.


Viewed at 03:02:30 on 18/02/2010 of 41.


-3-

Investigating for lignite, Fruzetti (1969) drilled 3 stratigraphic holes near the airstrip, some 2 km to the west of Ride's (1967) area of investigation. As the holes were diamond drilled, no groundwater information was recorded. Nevertheless the investigation showed that the thickness of the Tertiary sequence exceeds 163 m in the airstrip area. One of the holes intersected layers of coarse sand - a possible aquifer - between 73 and 84 m. The hole was abandoned because of caving problems.

Roberts (1975) appraised groundwater information after a borefield was established in the area recommended by Ride (1967). Roberts estimated the Tertiary sediments were 70 to 80 m thick; had an average coefficient of transmissivity of 50 m2/day and an average storage coefficient of 0.005. He calculated the'volume of groundwater flow through the borefield aquifer as 50 000 m3/year, about half the extraction rate in 1975. Extrapolating figures showing the increasing water demand of the community, he predicted the basin, as defined by Ride (1967), would be exhausted by the year 2000.

Wyche (1983) reported the drilling of lignite exploratory holes in locations ST 1 to ST 5 (Figure 2). Although the diamond drilled holes did not provide groundwater information, they considerably expanded available stratigraphic information. His report shows that the Tertiary sediments are thick at a distance of 8 km from the existing borefield (9lm in hole ST 1); and, in certain locations, extremely thick (over 146m in hole ST 3). In every hole the presence of layers of limestone, sandstone and medium to coarse sand suggests the possible presence of aquifers. Some of the logs seem to show a tendency of the average grain size to increase with depth, as in the case of transgressive profiles. But no correllation seems possible between holes, suggesting sedimentation took place in a depositional environment which must have varied significantly between localities at any time of deposition.

2.3 Bore Data Review

Bore information is presented in Table 1, which summarizes data on most bores drilled within the Santa Teresa Basin. Figure 1 shows the location of bores drilled within the borefield area.

An ins?ection of bore data and drilling logs, and the comparison of this information with the information summarized in sections 3.1 and 3.2 above indicated:

(a) The area covered by groundwater investigations at Santa Teresa was very small. Some 16 water holes had been drilled in Tertiary sediments, totalling 834 m drilled. Of these, nine holes, representing 595 m drilled, or 71% of the drilling effort, were sited within an area of 300 m by 700 m (0.21 km2

, Fig. 1). By comparison, the basin has an area of some 100 km'. Thus, over 99% of the basin was hydrogeologically unexplored, and its groundwater potential largely unknown.


Viewed at 03:02:30 on 18/02/2010 of 41.


-4-

(b) The vertical extension of groundwater information also was limited. Ten of the 16 bores drilled in the basin were less than 60 m deep and only two (RN 11851 and RN 7289) exceeded, by a few metres, a depth of 80 m. No bore had ever tested the basal part of the Tertiary sequence, nor penetrated below the Tertiary -Cambrian unconformity.

(c) Assessments made on groundwater flow, aquifer parameters, quality controls and groundwater potential of the santa Teresa basin - some of them predicting its imminent exhaustion (Roberts, 1975; Gribble and Ribeny, 1985), - had been mainly based on information provided by the relatively small area covered by Ride's (1967) initial investigations, and on the limits set by his proposed 'buried valley' model.

(d) Drilling at Santa Teresa presents difficult technical problems. Lack of stability of the formations; swelling clays; losses of mud circulation and failure to determine the exact position of aquifers found have been some of the common problems encountered while drilling.

(e) Production bores at Santa Teresa can fail with extended use. A possible cause is the blockage of aquifer materials, gravel packs or screens by fine particles. An inspection of strata samples of the area indicates the sediments drilled consist mainly of poorly sorted, unconsolidated fine sand mixed with varying amounts of silt and clay. If bores are pumped at high rates favouring turbulent flO1 ... (i. e., above recommended pumping rates), it is possible these fine particles could move so as to place themselves in gravel packs and screens and gradually intercept the flow. Slumping of clay layers and flocculation could also enhance this process.

(f) The behaviour of RN 11851 (production bore no 6, one of the most recent bores drilled in the area) seems to illustrate this clogging possibility. Recommended for 5 L/s, after it was drilled and tested in 1979, the bore gradually decreased its yield. A crew checked the bore in 1984 and cleaned it by adding dispersants and jetting the screens. On airlifting, the bore behaved as undamaged: no sand was found in the discharge. Nevertheless, the presence of large amounts of clay was noticed in the initial flow. A subsequent pumping test showed the yield had decreased to 3.5 L/s. Transmissivity values had also decreased, from 85 m'/day in 1979 to 39 m'/day in 1984. By 1986 the bore was capable of yielding only 1 L/s.


Viewed at 03:02:30 on 18/02/2010 of 41.


-5-

3. WORK PROGRAMME

A work programme was designed balancing needs for:

alleviating water shortages experienced by the Santa Teresa community.

identifying new aquifers, that may simplify the construction of bores and extend their usable life.

keeping costs of connection to the present reticulation system low by drilling within, or at a reasonable distance of, the existing borefield.

The programme was planned in three stages:

3.1 Stage 1: Tertiary Base - Shannon Formation Drilling

The aim of this stage was to test the base of the Tertiary sequence and penetrate the underlying Shannon Formation, in an attempt at identifying a groundwater source in consolidated rock. To reduce piping costs, a drilling site in the vicinity of production bore RN 11851 was selected. If the investigation hole was successful, a new production hole would be constructed and the project would terminate with this stage.

3.2 stage 2: Geophysical Survey

A geophysical survey, including resistivity traversing and vertical electrical sounding, was designed so as to obtain information on the thickness of the Tertiary sequence; on its horizontal continuity and on the shape and slope of the Tertiary Cambrian unconformity. Interest would be placed also on detecting high energy environments of deposition such as paleo-channels or downfaulted blocks, where coarse grained deposits could be found. The borefield area would also be investigated to further define the shape and limits of the "buried valley" suggested by Ride's (1967) investigations.

3.3 Stage 3: Further Drilling

Further drilling would be planned on the basis of results provided by stages I and 2. Its main aim would be to investigate new aquifers and subsequently construct production bores. The additional drilling would also provide control points for the geophysical survey_


Viewed at 03:02:30 on 18/02/2010 of 41.


-6-

4. RESULTS

The locations of bores drilled in this investigation are shown in Fig 2.

4.1 stage 1: Tertiary Base - Shannon Formation Drilling

4.1.1 Bore RN 14418

Bore RN 14418 was drilled 100 m to the northwest of RN 11851. Mud had to be used while drilling through the Tertiary sequence and therefore sample returns were poor. Nevertheless, the presence of coarse quartz sand and lithic pebbles was noticed in the mudflow between 83 and 89 m. At 90 m, a first hard layer of siltstone of the Shannon Formation was struck. Casing was run down to this depth and drilling continued down to 125 m, with air, through interbedded layers of siltstone, quartz sandstone, calcarenite and limestone.

various aquifers were struck in the Shannon Formation. The airlifted yield (A.Y.) of the bore and the specific conductance (S.C.) of the groundwater increased with depth as follows:

DEPTH

98 m 101 m 116 m

120 - 125 m

A.Y.

2 5 9

>15

L/S L/s L/s L/S

S.C.

1540 1940 2100 2300

pS/cm pS/cm pS/cm pS/cm

AS the groundwater in the Shannon Formation was of poor quality, in comparison with the existing water supply, bore Rn 14418 was constructed as a piezometer (Table 2). Below 89 m, the hole was sealed with bentonite to prevent the mixing of groundwaters.

4.1.2 production Bore RN 14847

This bore was drilled with mud 5 m east of RN 14418. It reached a depth of 89 m. As with RN 14418, a return of coarse sand and gravel in samples occurred after 83 m. Caliper, self potential resistivity and gamma logs were run after the hole was drilled.

A first attempt at constructing the bore was made by setting 1 mm aperture screens between 85 m and 87 m, where the caliper log and sample returns suggested a gravel layer may exist. This was unsuccessful: the airlifted yield was only 0.5 L/s.

The casing was lifted lower gamma readings, increased to 3.5 L/s. was 550 pS/cm.

2 m so that the screens faced a zone of at the 83 m 85 m interval. The yield

The specific conductance of the groundwater


Viewed at 03:02:30 on 18/02/2010 of 41.


-7-

Main information gathered by the Stage 1 bores was:

(a) The Tertiary - Cambrian unconformity lies at a depth of 90 m in the area of production bore RN 11851.

(b) In this area, the Shannon Formation has high yielding aquifers; but the groundwater quality is unfit for human consumption (Appendix 2). Water quality deteriorates with increasing depth.

( c ) Above the unconformity, coarse base of the Tertiary sequence. aquifer.

4.2 Stage 2: Geophysical survey

sand and gravels occur, at the The coarse sand forms an

A geophysical survey, combining resistivity traversing with vertical electrical sounding, was completed over the borefield and adjacent areas (Ritchie, 1987). The survey's results indicate:

(a) The Tertiary - Cambrian unconformity presents no paleo-channels nor downfaulted blocks in the vicinity of the borefield area and there is no evidence of the presence of a "buried valley· (Ride, 1967). Instead, the Tertiary sediments here form part of a continuous and extensive basin which, under the borefield area, deepens towards the west. Soundings made 1.5 to 2 km to the west and south-west of the borefield (Ritchie, 1987), seem not to have detected the basin's floor, suggesting it lies at a depth greater than 200 m.

(b) As the Tertiary sediments thickness increases from east to west, the deep layers of the sequence become less resistive, which could indicate that significant amounts of clay could be encountered disseminated throughout, or interbedded with, these lower strata (Ritchie, 1987). Alternatively, the low resistivities may reflect the possible presence of saline groundwater in deep sediments near the basin's centre.

(c) In an area studied close to the basin's margin, near Phillipson Bore (RN 5006, Fig 2), soundings detected relatively high resistivities at the base of the Tertiary sequence. This could indicate the presence of clean water bearing sand layers just above the Tertiary - Cambrian unconformity (Ritchie, 1987).

4.3 Stage 3: Further Drilling

An area was selected for drilling some 400 m north of bores RN 11851 and RN 14847, in the vicinity of vertical electrical sounding No 5 (Ritchie, 1987). Four bores were drilled in this area in a north-south line and at a distance of 5 m between bores.


Viewed at 03:02:30 on 18/02/2010 of 41.


-8-

4.3.1 Bore RN 14848

Bore RN 14848 was drilled with air, as a pilot hole. The drilling penetrated fine clayey sand interbedded with clay and silt. A supply of 3 to 4 Lis was airlifted at 70 m. The yield increased to 7 Lis at 79 m and, as the formation lacked stability, the hole collapsed.

Sieve analysis was carried out on samples airlifted from above and from below the first aquifer struck, each sample representing a 3 m interval. The grain size distribution of the samples was represented in hystograms (Fig 3). The hystograms showed that a coarse sand fraction appeared in the sample representing the 66 -69 m interval. The amount of coarse sand in the samples increased with depth and became predominant, as a second mode, from 72 m onwards.

The graphs in Fig 3 suggest that either a large proportion of fines was lost during the airlift, especially when groundwater was struck, or that the occurrence of groundwater could be related to the presence of one or more coarse sand layers below 66 m.

4.3.2 Bore RN 14849

Bore RN 14849 was sited 5 m south of RN 14848. The bore was drilled with mud. It had two objectives:

(a) to check the Tertiary sediments below the maximum depth reached by RN 14848, until striking the shannon Formation, and

(b) to test the aquifers found by RN 14848.

Loss of mud circulation made necessary to install a 254 rom casing to a depth of 53 m. Drilling continued, with poor recovery of samples in the mud flow, through interbedded layers of sand, clay and fine clayey sand down to 109 m. At this depth, below a 3 m thick clay layer, siltstone of the Shannon Formation was struck.

Telescopic screens of 0.5 mm aperture were placed between 73 m and 79 m. After 3 hours of development, groundwater with a specific conductance of 510 pS/cm was airlifted, free of sand, at a rate of 15 to 20 LiS. .

When the airlift was about to cease, the 254 mm external casing lost its support and began to move. It rapidly descended 25 m and crushed the screens. The bore had to be backfilled and abandoned after most of the materials used to construct it were retrieved.


Viewed at 03:02:30 on 18/02/2010 of 41.


-9-

4.3.3 Bore RN 14850

A second attempt at constructing a bore in the aquifers found by RN 14848 was made with RN 14850. The hole was sited 5 m south of RN 14849 and was also drilled with mud. This time a cement plug was placed at 73 m to support the external casing. Once the cement was set, drilling proceded. Dark carbonaceous clay was unexpectedly struck immediately below the plug. Drilling continued and no sand layers were found. Massive dark clay occurred between 73.2 m and the Shannon Formation, which again was struck at a depth of 109 m.

The casing was retrieved and the hole backfilled. A 25 mm galvanised pipe, extending down to 61 m, was placed to enable water level monitoring.

4.3.4 Production Bore RN 14851

Bore RN 14851 was sited also close to 14848, this time 5 m north. The bore was drilled with mud and cased down to 48 m. To improve sampling techniques, a cable tool rig was set over the hole and a drive tube sampler was used to take samples every 340 mm. After a sample was retrieved, the hole was enlarged and the casing pushed down. A new sample was then taken. This drilling and sampling procedure was repeated until the hole reached a depth of 69 m.

As samples were examined while drilling, each 340 mm interval appeared different in average grain size, and in sand, silt and clay content, from the preceeding one. In spite of these rapid changes, two larger intervals were noticed in which medium to coarse moderately sorted sand was predominant. Sieve analysis was carried out and screens were placed in front of these intervals.

Bore RN 14851 was airlifted at a rate of 3 Lis. Specific conductance of the groundwater was 460 pS/cm. Details on the construction of the bore are presented in Figure 5.

Main information obtained by stage 3 was:

(a) Medium to coarse sand aquifers, capable of airlifting up to 15-20 LiS, can be found outside the previous borefie1d area.

(b) Success in the construction of production bores depends very much on the drilling techniques used. In the present study, optimum bore design was achieved only after drilling provided accurate and representative samples indicating exact position and grain size distribution of the strata struck.

(c) The Tertiary - Cambrian unconformity lies at a depth of 109 m in the new area drilled.


Viewed at 03:02:30 on 18/02/2010 of 41.


-10-

5. WATER QUALITY RESULTS

water samples were collected while drilling and at the end of the pumping tests. Chemical analysis on the samples were completed by the water Directorate laboratories at East Point, Darwin. Results of the analysis of groundwaters struck by the two production bores, and by the bore drilled in the Shannon Formation, are presented in Appendix B.

Groundwater struck by both production bores, RN 14847 and RN 14851, comply with the Northern Territory standards for drinking water; i.e., they are suitable for human consumption. The TDS content of both production bores (slightly above 300 mg/L) is one of the lowest in groundwaters of Central Australia.

Groundwaters struck by Bore RN 14418 in the Shannon Formation are unfit for human consumption. The quality of the groundwater deteriorates with depth (Appendix B). Even at 98 metres, components such as Sulphate, Fluoride and Total Hardness have concentrations above standards set for potable water. The water is, nevertheless, suitable for cattle use.

Groundwater quality in both production bores is similar in TDS contents. Nevertheless some differences in composition can be noticed. For instance, the groundwater in bore RN 14847 has noticably higher concentrations of sodium, Chloride, sulphate and Fluoride (Appendix B), which could reflect its proximity to the Shannon Formation. Groundwater in bore RN 14851 has higher concentrations in Calcium and Nitrate. This last component almost does not occur in the groundwater struck in depth in the Shannon Formation.


Viewed at 03:02:30 on 18/02/2010 of 41.


-11-

6. PUMPING TESTS

Bores RN 14847 and RN 14851 were developed by pumping and tested. Testing of each bore included a preliminary pumping test, 5 step tests of 100 minutes each, and a 24 hour constant rate test. After the constant rate tests were completed, the recovery of the bores was recorded.

Time-drawdown graphs and technical data obtained by the pumping tests are presented in Appendix A. Test reports and recommendations relevant to the use of the bores are presented in Table 2 and Appendix A. These show that each bore can sustain a maximum continuous pumping rate of 5 Lis. Recommended pump setting depths are 80 m for bore RN 14847 and 57 m for bore RN 11851 (Appendix A).


Viewed at 03:02:30 on 18/02/2010 of 41.


-12-

7. CONCLUSIONS

7.1 The present study was successful in achieving its objective. Two new production bores capable of upgrading Santa Teresa's water supplies from 7 to 17 Lis were constructed. The bores were screened in coarse sand aquifers. The groundwater supplies are potable and their TDS contents slightly exceeds 300 mglL (Appendix B).

7.2 This success partly depended on the exploration strategy adopted for this study. As a result, the area covered by previous groundwater investigations was expanded and previous maximum drilling depths were exceeded, so as to penetrate the base of the Tertiary sequence and the underlying Shannon Formation.

7.3 The new information so obtained (Section 4.1 and 4.3), combined with the results of a geophysical survey (Section 4.2), indicates that no "buried valley" occurs at Santa Teresa's bore field (Ride, 1967). Instead, the aquifers at the borefield form part of a continuous sequence of sediments deposited in a relatively large Tertiary basin. The basin has an extension of approximately 100 km" (Fig 2) and a maximum depth probably exceeding 200 m (Ritchie, 1987).

7.4 This much larger volume of the basin has implications on groundwater availability at Santa Teresa. As the aquifers are not contained within the boundaries of a buried valley, groundwater resources available to the community could be much more extensive than previously estimated. A further evaluation of these resources may prove it is unlikely they could easily become depleted (Roberts, 1975; Gribble and Ribeni, 1985).

7.5 Nevertheless, the real groundwater potential of the basin still remains unknown since, up to the present, this and other groundwater investigations have covered only an approximated 1% of the basin's total area and no regional investigation has been carried out.

7.6 Exploratory drilling suggests that yieldS of up to 15 to 20 Lis of potable groundwater could be airlifted from a single bore drilled in Tertiary sediments (Section 4.3.2). Production bores may achieve similar yields, if groundwater exploration and bore construction techniques are refined further and adapted to this specific area (Section 4.3).

7.7 Underneath the Tertiary sediments at the borefield area, rocks of the Shannon Formation occur. Where drilled (Section 4.1), these rocks contain high yielding aquifers which can provide groundwater supplies unfit for human consumption (Appendix B), but probably suitable for other uses (Section 5).


Viewed at 03:02:30 on 18/02/2010 of 41.


-13-

7.8 The unstable nature of the Tertiary sediments persisted in the new area drilled (Section 4.3). Production bore construction was achieved in this new area because drilling techniques involving accurate strata sampling were applied (Section 4.3.4).

7.9 Drive tube sampling showed that thin layering and lamination controls the bedding patterns of the Tertiary sediments. Abrupt changes in texture, especially in grain size, and in clay contents can occur over short vertical distances (Section 4.3.1 and 4.3.4). Such changes seem to occur also over short horizontal distances (Section 4.3.3).


Viewed at 03:02:30 on 18/02/2010 of 41.


-14-

8. RECOMMENDATIONS

8.1 Bore Management Recommendations

8.1.1 Bores RN 14847 and RN 14851 (Fig 1) should be equipped for production. Pumps should be installed at the depths specified in Appendix A, Fig 4, Fig 5 and Table 2; i.e., at 80 m in bore RN 14847 and at 57 m in bore RN 14851. The recommended continuous pumping rate is, for each bore, 5 Lis.

8.1.2 The 5 Lis continuous pumping rate should not be exceeded. Excessive pumping rates may create turbulence and mobilize particles of silt and clay which can cause blockage problems in gravel packs and screens. Such problems would affect the long term capacity of the bores.

8.1.3 water meters should be installed on each production bore. Volumes of groundwater extraction should be recorded on a weekly basis.

8.1.4 Standing water Levels (SWL) should be measured in the area of the new production bores at least once a year. Piezometres RN 14418 and RN 14850 (Fig 1) should be used for SWL recording. RN 11851 (production bore No 6) should be decommissioned and also used for this purpose.

8.1.5 Production bores RN 14847 and RN 14851 should be sampled every 3 months during the first 3 years of operation, and every six months thereafter. The sampling of bore RN 14847 is especially important, as its screens are placed not far above the Shannon formation, which contains slightly saline aquifers (Section 4.1).

8.2 General Recommendations

8.2.1 A new monitoring bore should be drilled in areas further away from the influence of the borefield's core of depression, with the purpose of measuring regional variations of SWL. Such variations will permit to predict long term effects of pumping.

8.2.2 Drive tube sampling, or any drilling method permitting accurate recovery of samples, is recommended for the construction of production bores at Santa Teresa. As the grain size distribution of the basin's sediments often changes abruptly over short vertical or horizontal distances, the information provided by accurate sampling is critical to achieve optimum bore design (Section 4.3).


Viewed at 03:02:30 on 18/02/2010 of 41.


-15-

8.2.3 The Santa Teresa basin, as defined by its mapped area (Fig. 2) and by the thickness of its sediments (Ritchie, 1987; Wyche, 1983), has a much larger volume than estimated in Ride's (1967) early "buried valley" model. Therefore, calculations made using this model as a basis, especially those predicting the exhaustion of santa Teresa's groundwater supplies in the near future (Roberts, 1975; Gribble and Ribeni, 1985), should be revised, after assessing the real extent and regional characteristics of the aquifers involved.

8.2.4 If Santa Teresa's future groundwater demand significantly exceeds the present supplies, a regional investigation should be carried out. Such an investigation should aim at defining the basin's total potential for groundwater extraction and the location of aquifers permitting the construction of high yielding bores. As a result:

Future water shortages at Santa Teresa could be prevented.

The productivity of the land could increase, through the expansion of agricultural and horticultural operations.


Viewed at 03:02:30 on 18/02/2010 of 41.


9 . REFERENCES

FRUZETTI, 0, 1969

GRIBBLE, D.B., & RIBENY, F.J., 1985

-16-

"Geological Notes on Santa Teresa Lignite prospect" - (unpublished). Northern Territory Geological Survey Report G.S. 71/10 Open file.

"Santa Teresa water Supply Review" -(unpublished) . Report by willing and Partners Pty Ltd for the NT Dept of community Developmen t.

RANFORD, L.D., COOK, P.J. "RODINGA, NT" - 1:250 000 Geological & FETHERSON, J.M., 1964 Series. Explanatory Notes SF/53-2.

RIDE, G, 1967

RITCHIE, T, 1987

ROBERTS, K.P. 1975

WELLS, A.T., FORMAN, RANFORD, L.C., & COOK, D.J., 1970

WYCHE, S., 1983

"The santa Teresa Groundwater Basin" -(unpublished). Northern Territory Administration, Water Resources Branch, technical report 1967/R7.

"Resistivity Survey - Santa Teresa" -(in preparation). Power and Water Authority, Water Resources Group, Alice Springs. Report 1986/1.

"Basin management Report - Santa Teresa" _ (unpublished). Department of Northern Australia, Water Resources Report.

D.J. "Geology of the Amadeus Basin, Central Australia" - Bur. Min. Resour. Aust. Bulletin 100.

"Lignite occurrences in the Southern part of the NT" - (unpublished). NT Geological survey Report G.S. 83-14. (Open file).


Viewed at 03:02:30 on 18/02/2010 of 41.

I I -17-

I I I I I I I I

FIGURES 1 TO 5 ---

I I I I I I I I I I

Technical R

eport WR

A89020

View

ed at 03:02:30 on 18/02/2010P

age 22 of 41.

--------------------to ~'"" ,..I

DARWIN

D,

NORTHERN

\ Tennant Cr.ek

\i

\ TERRITORY ... .. " '

\ Allco Springe I SANTA TERESA I /'

L L~ / I

I

/ /

/' ,/

:1 ..

T I --o gant I ,..----• rer )/ - .a. l/k " ...... -_.... I1J ,../ ------------,.; ...

LEGEND

:\ Windmill

l!l Production Bor.

" ~ Ob,enratlon Bor. 0051111 --G:> • BAckfilled Bore

14418 Reo!siered Number ot Bore -I. --- -- TrACk

Not., Th ... bor .. al Ihown a,. epproxlmate t5 metr •• apart

148111 C!l ·14848 • 148491 14850 'Y

I

/ I

/

I ..... ,_ I "r .........

I _-".,. ......... -- , / ,,~ ! )6Phllllpoon Oor.

f /,,'" 5006 I "

/ " / ,,'" 1 ,,'"

NEW AREA Pllt::e:r. ~'~! !"'".---,. ..... '" 1'-,/ I /

" I ,," 14418 ",'" " '14847 ;" I I'

.... '" /' \1 :: ,. ..... " 11520£/ ,," 11861'Prod. No 6

,. Y'-"" I/J "-""...... -~ /' // 7149 :,

",/ ,..--- ..... - 'jr"'~-

,.;' ,/ a I '" n07-®- 5711-(~P285 Prod. No 3

7362 PrOd. No 5 C!l '/ / I//!! 1209~90 Prod. No 4

// :.'~ " .. e

I" e ~/ ,,'

---0,..... .l ,~

FARM ~ ~..,

.. .. ..

\\

, , l :

+5718

~'::.

.. , . , ,

o 400 800 1200 1600m

SANT A TERESA BOREFIElD

LOCATION OF PRODUCTION AND OBSERVATION BORES


Viewed at 03:02:30 on 18/02/2010 of 41.

--------------------

~ ~Pzm MEREENIE SANSTONE

SHANNON FORMATION

GILES CREEK DOLOMITE

TODD RIVER DOLOMITE

TERTIARY CHALCEDONIC LIMESTONE SILSTONE AND CALCAREOUS SANDSTONE

.

+ -44530

ST30

HUH

••••••

DIP AND STRIKE OF STRATA

SYNCLINE

FAUL.T

BORE

WYCHE'S DIAMOND DRILLED HOLES 1983

FRUZETTI'S AREA OF INVESTIGATION 1969

TRACK

CREEK

APPROXIMATE BOUNDARY OF TERTIARY BASIN

APPRO XIMATE BOUNDARIES OF RIDE'S (1967) BURIED VALLEY

SANT A TERESA GEOLOGY FIG. 2 (adapted from BMR 1:250000 geological map SG 53-2 1972 edition)

J I

Technical R

eport WR

A89020

View

ed at 03:02:30 on 18/02/2010P

age 24 of 41.

-n -(j) 0)

--------------------57-60 melros

60-63 melres

63-66 melres

66-69 metres

30

25 r-

I-

h i :: 1;~ II Llli:=J . ,

~ g ~ ~ ~ ~ ~ 8 ~ .... .... N (? ~ h (S ...

~ ~

Oca.h SilCl (rnbona)

30 1 I 25

I-

I--i :: 10

~HII~I' l!Jg:iloO~~~8~ ....... N~~ ..... ~"t

~ ~

Grain Stle (microns)

3D. r-25

.. 20 .. ! 15

I-

I-

I:H II thn . 30

25

i 20

a 15

10

~ g g ~ ~ ~ Q 8 ~ ,... .... N Co) 10 ,... 0 '"

~ ~

Grain Size (microns)

1-11,,---.

~UIIIII~ ~ g ~ ~ 8 ~ ~ 8 ~ """,, ... ~,,(»Ii)"O""

~ ~

Gl"aln Size (microns)

69-72 metres

72-75 metres

75-78 mot res

78-79 metres

GRAIN SIZE DISTRIBUTION SAMPLE RETURNS RN 14848

30

26

~U I DIrfhJ i 20

~ 16

10

30

25

.. 20 ~

I? 15 t!

10

5

~ ~ ~ ~ ~ ~ ~ ~ ~ OrAln SlzlII (rnl,cmna)

o boO g g ~ § OJ ~ .. ~

f-b e ~ ~ ~

30

25

i :: 10

O(aln S,lzft (mk;ron,s)

II-

:U II n II Ch

.. 30

25

• 20

115

10

~ 2 g ~ ~ g § ~ 8 .,.. .... N (1) 16 ,... .... ,... 2

Grain Slzo (microns)

r-I-

h-- ~ ~U I WJ I tb

~ 2 ~ ~ ~ g Q ~ ~ ... .... N (I') to ~ (5 ~ ~ ~

Grain Size (mlcrOfiS)

0----

0,--4

AClOI,r-ER YI'ELO 3 LI.

AQUIFER YIELD 7 Lis

(Orlmng ceased, hole caved In)


Viewed at 03:02:30 on 18/02/2010 of 41.


SWL on 2/10/86 18.68m

Recommended pump Intake setting, 80m

Steel cap

205mm Internal diameter, blank steel casing

1-<::--:::>1 83

205mm ID stainless steel screen,!., 1:::;;: aperture 1 mm " lIS 205mm 10. blank

\ 85 steel casing

\ Blank end plate

CONSTRUCTION DETAILS RN 14847

SANTA TERESA

Ground level

10

20

30

40

50

60

70

80

gOm

FIG. 4


Viewed at 03:02:30 on 18/02/2010 of 41.

Technical R

eport WR

A89020

View

ed at 03:02:30 on 18/02/2010P

age 27 of 41.

- - - - - - - - - - - - - - - - - - - -TABUi: 1 (Page 1) BORES DlUJ.L£D In 'l'l1E SANTA TERESA AREA DEtORE 19 lUi

(Mo~t positions plotted on Figa. 1 and 21

FORMll.~ ESTIMATSO T.n.S. s.W.L.

RN NABE TION GEOLOGY YIELD Lis AQUIFERS (m9/L l (m) nENARKS

2612 Yam Junction bor. T? 0-44.8m Clay, Gra,vtiil 1." 35-39.6 \tlEiAthored 550 ?

3266 Yam Creek No 3 e. O-I3.1m Limestone 0 - - -

32131 Vam Creek No 2 G, 0-36.5m Limestone "Small" - - 27.8

l292 Phillipson Bore r O~23m Cla.y 1 23-32.6m. Sand 550 20 Bore sited so as to inter30ct ea

23~32. 6m sand (Shannon Fran), but t8r~inated in T.

HAn always had 5andin~ problems

(perforated casing).

3316 Garden Bore G,1 0-30.451'1 ? 1.5 1 1191 25.9

T1

4121 Advice 30/2 T 0-30.Sm CalCAreous 1 0-25m CalCAreous Siltst 2356 25 Geologically logged

Siltstone I

445) Abraham's or or 1 Gypsum 0.6 1 2782 13 .0 I

Jacob's Dore I

5006 Phillip~on bore T 0-30.511. ClAy 1.0 32.5m Sand,Gravel 598 21 TBfit pumped !

No 2 30.5-35m sa.nd, GrAvel I

5775 M 1 T 0-36.Sm clay 1.5 18.3n IBBI}. 46 Geologically logged I

36.5-46.2~ sAndy CLAY 36-43r. sand

'----. - .- . ... - --~ --- - .. -.---. (continued)

Technical R

eport WR

A89020

View

ed at 03:02:30 on 18/02/2010P

age 28 of 41.

- - - - - - - - - - - - - - - - - - - -TlillL£ 1 (PllI.ge 2) nodS DRILLJtD IN mE SANTA TIi:H'SA AD.EA ol!:.P'ORE. 1986

(Host posltion~ plotted on Figa. 1 and 2)

rOJItMA- ESTiMATED '1'.O.S. S.W.L. RN NAME TION GEOLOGY YIELD LIS AQUIfERS ("'giL) (m) REMARKS

5776 " 2 T 0-16.5m Ch.y 1.5 32-36m clayey aand 3799 15 G~olo9icAl1y lO9ged

l6.5-39m clayoy sAnd

5777 M 3 T 0-10m Sand 2.5 21.4-36m Coarss, 380 17.3 Gaologically lO99&d to-12m LimeatonlJ ciil.t"bonaCG01l5 sand

12-36m COA["56 sand

7149 M 4 T 0 -22. 9m Clay I sandy 4.0 30.Sm Gravel 330 16.9 Next to Production No 3

guvel

22.9-46.2m Clayey sand 39.9m Sllnd And gravel

7287 " 5

T 0 -15m Sollndy gravel 1.3 16.2m rine sand 487 17.1 15 -39.6m Sandy clay

39.6-73m Interbedded

Sand Ii Clay

7288 Production No 3, T 0 -12.2m Gravel, clay 5 19.8m sandy clay 320 17.5 Tandency to fork. Test pumped.

M 6 limestone

12.2~41.9m Interbedded

sand " clay

7289 M 1 T 0 -13.7m S&nd , gravel ? 21. 3m. SAnd ttGood" ? Apparently not constructed as • 13, '7-1Sm Clay " s&nd production hole, Location .,Om. SW

18 -81J1l silt3tone of Production No 4.

7290 Pt'oductio-n No -4 T 0-18m sand, ah.y and 5 19.8m FinG sand 310 17.7 O.381mn Screens. Test pumped.

" 8 18-72.2m lnterbedded san( 55- 72~ Find sAnd Forking problems.

and clay

_~_L..... -~ ~- -~~ - ~

(continued)

Technical R

eport WR

A89020

View

ed at 03:02:30 on 18/02/2010P

age 29 of 41.

- - - - - - - - - - - - - - - - - - - -TABLE 1 (pago 3) 8Oru:S DRU.l.ED IN TH& SArITA TERIi!'SA A1tEA DEFO}iS 19816

(Most poaitionB plottGd on Fi9~. 1 and 2)

FORMA- eSTIMATED T.n.S. S.W.L.

RN NAME TION GEOLOay HELD LIS AQUIFERS (mg/L) (m) REI1ARKS

7352 Production No 5 T 0-4S.8m Interbeddod 1.2 16 .8m Fine sand 340 16.7 Pump tuted.

H 9 fine sand, CIA} 19.8m fine sand 48-61m SAnd L. gravlJl 41.10 rine sand

10619 H 10 T 18.3m ? 0 - - - Drilled only to find top of aquifer

11526 M11 T 0-14m Sand, sandstone 0.5 lO.SPI' sandstone 260(30m 16.3 150m NW of Production No 3.

14-28m Clay 28.4m Sand 550 (70m)

26-73.3m Sand, clay and

paat

11850 T 0 ~17.5JJ1 Sand, limest 3 48.17m sand, clay ? - Drilled 300m N of Production No 3.

17.5-53. <tm sand, Clay construction problsRs. Abamdoned

sandstone uncased.

11851 Production No 6 T 0 -15.51'1\ Sand,limeat 5 52~~BJII vary fine sand 340 17.7 Yield decreased to 1 Lis between

15.5-84.6m Sand to: Clay 55-56m VGry fine sand 1979 dnd 1986.

62-63m vary fine sand

70-71m vary fine sand

'---. ---- - - - ---


Viewed at 03:02:30 on 18/02/2010 of 41.

I I

TABLE 2

I DATA O~i CONSTRUCTED HOLES AT SANTA TERESA (19B5)

I RECOMMENDED TOTAL SCREENED PUMP

RN STATUS PUMPING DEPTH DI.AMETRE INTERVALS SETTING LOCATION

RAT!: • * •

I I

14418 Observation - 89 m 50 mm pip-e - - 5 ro west of RN 14847

insid~ 207 "'" 10'0 m lIlorth of R.~ 11851

casing. The {production No 6) •

casing ~xtQnds

to 83 m.

I 14847 Production 5 Lisee 86 m 207 mm casing 83 to 85 m 80 m 5 m east of Rn 14418

approx 100 m North of

I RN 11851 (Prod No 6) .

I 14850 Observation - 61 m 50 """ pipe - - ApproK 400 m North of

RN 14.34'7. 15 m south

of 1m 14851.

I 14851 Production 5 L/sQC 68.3 m 207 ml!l casing 58.55 m to 57 m Ap~rox 400 m north of

down to 32 m 61.55 m RN 14-847.

I 152 m1'3 casing 65.55 m to

from surface 66.85 m

to 57.SSm

I 127 nun casing, with 127 "'"

I screens, from

57.55 t-o 68.35 m

I

I I • DEPTHS AS MEASURED FROM THE GROUND SURFACE

I I I I I


Viewed at 03:02:30 on 18/02/2010 of 41.


-18-

APPENDIX A

PUMPING TEST REPORTS

ON BORES RN 14847 AND RN 14851


Viewed at 03:02:30 on 18/02/2010 of 41.


P()WER...?~ w~'f.~R~~WATER RESOURCES GROUP

TEST REPORT - BORE RN. 14847

Bore location: Santa Teresa Borefield Client/owner: Santa Teresa Settlement Client's reference: Purpose of supply: Settlement water

Supply Map: SG 53-2 Rodinga Grid reference: 223 9 9 8

RECOMMENDATIONS Pumping rale: 5 • 0 Us. Pump setting: 80 • 00 m below ground level General recommendations are given on the reverse side. The aquifer and bore ~cannot sustain higher pumping rates with deeper pump settings Of for short periods in favourable seasons. Further advice can be obtained from: Water Resources (In all correspondence refer to the bore's RN number). 1I.1ice Springs

BORE DATA Finished depth: 89 .14m Completion date:2/10/86 Standing water levell8. 82 m on13/10/86 Construction details:

AQUIFER TEST Test date: 16/10/86 Test rates: Test duration

Interval (m) DeScription

205 rom ID Blank Steel Casing

6.05 Us 24 hrs

0.24 83 85

above GL to 83 85 86

205 ~m ID x 1 rom Aperture 55 Screens 205 rom ID sump

Notes: 1. Top of casing as constructed was O. 30m above ground 2. All depths are measured from natural ground level 3. Test rates are not indicative of safe long term pumping rates.

WARNING: MINIMUM INTERNAL BORE DIAMETER IS 205 mm

COMMENTS

It is calculated that a pumping rate of 5.0 L/s the drawdown should be approximately 45 m.

~~----------------------------------------------------------------~/

WATER QUALITY

See water laboratory report (Analysis No.


Viewed at 03:02:30 on 18/02/2010 of 41.

RECOMMENDATIONS FOR FINISHING, OPERATING AND PROTECTING GROUWlWATER BORES I

AlIent,on tn the following poinls will ensure a long and sal<; lile for the bore supply and help prevent pollution of the I groundwater resource.

1. Construct a cencrete apron around the bore head to prevent surtace flow, seepage and waste from entering the

~. I 2. Seal the space between the casing and pump equipment to prevent entry of vermin, dirt and pollutants.

3. Maintain pumping equipment in good order to prevent pollution. Prevent spillage of fuel and oil on the ground I around the bore. Store fertilizer and other chemicals.at leas! 50 m away.

4. Keep stocK away from the bore head. Discourage dfllOt:stic activity a! the bore. The iirst tap on the pipeline

should not be less than 5 m from the bore head. I 5. Pumping the bore at higher than reccmmended ral"s may fork the bore leading to instability or pump

maintenance problems. Seek Ihe professional adVIce 01 an hydrogeologisl or groundwater engineer.

6. 11 the bore is no longer required, the casing is 10 be removed or securely capped and the bore backfilled with I ctayey malerial. A cement plug may be required in some instances·

In addition. please ensure that the BORE IDH1TIFICATION TAG is retained securely at ail times. The registered I bore number is Water Resources Division's only referenCE< to thE< scientific and engint:ering dala on this bore, and hence important to WRD's further advice to bore owne,s. .

I I I I

BORE LOCATION MAP I I I I I I I I


Viewed at 03:02:30 on 18/02/2010 of 41.


o

0

~

o

p

o N

0 0

0

o r<l

~

0 0

0

o 7

0

(San9W) NMOGMVHG

0 0

0 0

0

0

0

o l!)

:

,

~ 0

0 0 0

0

.

D

C/) ...... ...J

<0

II

0

o <ll

r--~

0 CO 0 0 .qo ,.. 0

Z 0 l!) a:

0 0 ...... - <J)

Q) -:::l C o .-

I{) E ~

W ~ I-

o

.... 0> - '" <C I 0>

X I

'" Cl I'--

Z CD

W C\l

0-~O-(J)<C UJ ~ UJ ~ a: « J: () (J) -C ~ Z

~ (/) Z 0 ()


Viewed at 03:02:30 on 18/02/2010 of 41.


.

o

. .

.

. . . .

.

o

C/) ....... ...J CIJ

II

0

. · · · · · · · · · · . · · ·

C/) .......

C/) C/) ...J ....... ....... <0 ...J ...J 0 (I) .q- •

10

II II It

0 0 0

i , . .

. : . · .

· · · · : . . .

o 0 <0 '>l"

(SaJlaW) NMOGM'fClG

.

o lD

.

C/) ....... ...J

10 0 . <0 II

0

! ,-

o (!J

....... 1-~C/) coUJ ~I..... Z Z3= "g ~ '" o a:

"! oW ~ I-

o

c 0-UJ IC/)


Viewed at 03:02:30 on 18/02/2010 of 41.

I PO~~P{~ I ~~w!:m«~. ~WATER RESOURCES GROUP

I I I I I I I I I I I I I I I I I I

TEST REPORT - BORE RN. 14851

Bore location: Santa Teresa Borefield ClienVowner: Santa Teresa Settlement Client's reference: Purpose of supply: Communi ty Water Supply

Map: S8 53 - 2 Rodinga Grid reference: 233 999

RECOMMENDATIONS Pumping rate: 5.00 Us. Pump setting: 57.00 m below ground level General recommendations are given on the reverse side. The aquifer and bore ~Icannol sustain higher pumping rales with deeper pump settings or for short periods in favourable seasons. Further advice can be obtained from: ,\Tater Resources (In all correspondence refer to the bore's RN number). Alice Springs

BORE DATA AQUIFER TEST Finished depth: 68. 33m Completion date: 8/10/87Test date: 22/10/88 Standing water leve119.62 m on 14/10/86 Test rates: 6.05 Construction details: Test duration 24

Interval (m) Description o 32.00 207mm 10 Blank Steel Casing o 58.50 142mm 10 Blank Steel Casing 58.55 61.55 127mm 1D 0.5mm APT 55 screens 61.55 65.35 142mm 10 Blank Steel Casing 65.35 66.85 127mm 10 O.6mm APT 55 screens

Us hrs

66.85 68.33 142~~ 10 sump NOTE: 57.55m - Top of packer Notes: 1. Top of casing as constructed was 30 m above ground

2. All depths are measured from natural ground level 3. Test rates are not indicative of safe long term pumping rates.

WARNING: MINIMUM INTERNAL BORE DIAMETER IS 127 • mm

COMMENTS

As some signs of instability were noted during the pumping test, it is recommended that this bore be retested at six months to one year after the commencement of production pumping. The existing ~um~ installation should be utilised, and thus provision for an a~rl~ne to monitor drawdowns must be made.

It is calculated that at a pumping rate of 5.0 L/S the drawdown should be approximately 30m.

~~--------------------------------~-----------------------------/

WATER QUALITY

See water laboralory repor1(Analysis No.


Viewed at 03:02:30 on 18/02/2010 of 41.

RECOMMENDATIONS FOR FINISHING, OPERATING AND PROTECTING GROUWlWATER BORES I

Allention to the lollowing points will ensure a lung and safD life for 11 Ie bore supply and help prevent pollution 01 the

groundwater resource. I 1. Construct a concrete apron around the bore t,ead to prevent surjace flow. seepage and waste from entering the

bore.

2. Seat the space between the casing and pump equipment to prevent entry of vermin, din and pollutants. I 3. Maintain pumping equirment in good order to preve,,1 pollution. Prevent spillage of luel and oil on the ground

around the bore. Store ferlilizer and other chemicals at teast 50 m away. I 4. Keep stock away from the bore head. Discourage dnl1l8stic activity at the bore. The first tap on the pipetine

should not be less than 5 m from the bore head.

5. Pumping the bore at higher than recommended raks may fork the bore leading to instability 0< pump I mainlenance problems. Seek the prolessional adVice 01 an hydrogeologist or groundwater engineer.

6. If the bore is no longer required, the casing b to be removed or securely capped and the bore backfilled with I clayey material. A cement plug may be required in some instances.

In addition. please ensure that the SORE IOEt!TIFICATION TAG is retained securely al all times. The registered bo,,~ number is Water Resources Division's only referenc" to the scientifIC and engin",ering da'!a on this bore. and I hence imparlant to WRD's fUrlher adVice to bore owners.

I I I I

SORE LOCATION MAP I I I I I I I

Technical R

eport WR

A89020

View

ed at 03:02:30 on 18/02/2010P

age 38 of 41.

--------------------10

15

,.... ~ 20 ... ..... <1)

E ...., z 3: 25

g ~ Ci 30

35

40

r-

0

0

0 00

0 0

0(.)", r.. 0 0

"'~ \;J '" 0 0 '" 0

o 0 '" , 0·

0(.). 0 0

v

Note: At time 25 min. significant discharge of sands, Q=6 LIs

0 thus suspect part aquifer collapse

~~ ..... '.. . l?iO .

5 10 50 100 500 1000

TIME (minutes) RN 14851 CONSTANT DISCHARGE TEST

APPENDIX A/3 2673-9-39


Viewed at 03:02:30 on 18/02/2010 of 41.


.

(/) -..... ...l 0 · C\I

II

a

· · · · · · · · · ·

· · · · · ·

· · · · · · · .

·

· .

o

(/) (/) (/) -..... -..... -..... ...l ...l ...l (1) I"- <0 0 0 0 · • . (1) ~ 10

II 11 II

0 0 0 ... / .'

. . i .' . . · · · · ·

· · : · · · · · ·

o 10 N N

(S9J+8W) NMOGM'il:::IG

o r<l

(/) -..... ...l It) 0 . <0 . II r

.> 0/

10 r<l

'" o

o

w ~ I-

'=t 0 ......... « I 0)

X I to Q r-Z <0 W N a. a. «


Viewed at 03:02:30 on 18/02/2010 of 41.


-19-

APPENDIX B

WATER QUALITY DATA OF BORES

EN 14418, RN 14847 AND RN 14851

Technical R

eport WR

A89020

View

ed at 03:02:30 on 18/02/2010P

age 41 of 41.

---~------- - - - - - - - - - --a: w Ul_ -to W 9U UJ ::'! U -,0 (') 0 ;:, z 0 0

~ z "" Ul~ 0 (') 1-- U D U 01- <n

~ :r: -' III ~ ;:,- W"" ell III '" ..- :r: u: :< (') . -' OU >, '" UI u. 0

~ U UI 0- 20 _J 0 ... Z ::-j :~J U Ul 0 LL ::;; I

1- :;: 0.( . '" ;.{ ~ '-t~) N Z en UI Ol(] U ~ ,-~ .-( 0 .(

~ ,

III > ru 5 ... t l • t~ Z I-m u 1_ Z . 1- m III 1I1 Ul UlUJ -, ,- « <> -'0 0 8 III 0 0 z UI

~ g« B ':-.... m <n :r. u .o,u ,,; UJ ....,: ;"-') W c, ..: n: 1- m

~ a: Pc 5 .JnI ~j v, I '" ~8

:1_ ,~ n: -g ::; w .. .:( ~ .( 0 :1.': ;j: (,) Z !2 ~ ~ ~ « ::;; HI u .. C) ;:~ (~) U .( LC I- ul ill 6 c'n 1- 1-;< (f) 1- Ul 0 U ::J 0 0 (§ 0."- :J: c> 0 « 0.,.: o .~ n: d ::J

Z iii tr NO U 1- .§. VI a, 0 :i 1-- - I·" --- Ul U (II z_ '" Ul- n. -

IL4A.lB 28.1.86 lli.Q1l. ll3.Q __ _1.2-_ ~lL _lL_ _129 __ _TL_ .ii.3L 211 1,7 .14. ___ . .s0 .!i.52- 1 257 1 8 .l3L

(98m) ---- ------------.- ---- --, - - ~

4418 28.1.86 1950 1510 7.6 138 12 178 96 ...[39_ ..202 __ )l0 14 104 750 1 246 2.1 171 ---- --- ------ -

(101m) -- ---- ---'--- -- .. -- - ' -

4418 28.1. 86 2270 1830 7.7 170 13 210 110 980 190 6.4 14 13Q 1950 <J 230 .2..2- ')')('\

~~"--- --- ---- --- I

(125m) I ------ ------- ,--, -I

4847 17.10.8E 540 315 7.3 20 4 47 25 262 228 0.4 19 18 40 1 278 0.8 10 I

I

--------- -4851 23,10.86 505 305 7.3 7 4 68 21 256 238 0.2 19 10 14 15 290 0.3 18

----- ---_.- ~--. -- -------- ,

---_ .•. ---, ---- '---' ._ ... --, --.- _ .•.. --,----

- ---.--- .. ----... -.--~- .. -. ---.----... - ---- ----- t-----

--- --- .. _-"'-.. -' ---- .. --- -..... ---.. --..•.. ---. --.~ .. --. . -~---- ----"-- .~.-.

• . '-.- .. --.. .. -."--".- ---- .. --. --'-'-- -"'------ .. _----- - ---~- --.-.-.

-- -Anal,oi, ill lIlil\,i~IilIllS pCllilfo - II~JIl (unless olherwiso s1310d)

WATER QUALITY DATA Table 8f 1

SANTA TERESA - Territory Stories: Home€¦ · Santa Teresa obtains its present groundwater supply...

Documents

Transcript of SANTA TERESA - Territory Stories: Home€¦ · Santa Teresa obtains its present groundwater supply...