MOUNTAIN HOMES WBILE..' HOM3 PARK

Transcription

1 I..! MOUNTAIN I I.i, '..... GROUEJDWATER SUPPLY FOR MOUNTAIN HOMES WBILE..' HOM3 PARK SOUTfl OF KALEDEN, B. c., I PACIFIC HYDROLOGY SEPTEMBER CONSULTANTS LTD. 28, 1988

2 MOUNTAIN HOMES LTD. GROUNDWATER SUPPLY FOR MOUNTAIN HOMES MOBILE HOME PARK SOUTH OF KALEDEN, B. C. PACIFIC HYDROLOGY CONSULTANTS LTD. SEPTEMBER 28, 1988

3 E. LIVINGSTON. P. EW. A. BADRY PACIFIC HYDROLOGY CONSULTANTS LTD. CONSULTING GROUNDWATER GEOLOGISTS WEST BROADWAY VANCOUVER, B.C. V6J 123 TELEPHONE: (604) September 28, 1988 Mountain Homes Ltd. c/o 528 Main Street PENTICTON, B. C. V2A 5C7 Attention: Mr. P. E. Locke, FRI., A.A.C.I. Subject: Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. Dear Sir: This letter is further to our (Locke, Livingston) discussion of August 27 onsite at the Mountain Homes Well about groundwater for the proposed Mountain Homes Ltd. Mobile Home Park. 1.0 INTRODUCTION From the aforementioned site discussion, and also from several telephone discussions, we understand that the situation is as follows: 1. Mountain Homes Ltd. is planning to develop a mobile home park on the hillside east of Highway 97 south of Kaleden. Phase I of this development calls for 50 mobile home units. Future phases of development may result in a total of 150 units..../2

4 , Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page 2 2. A 200 mm (8") diameter well has been constructed by Quality Water Wells on an easement on the Leir Farm on the south side of White Lake Road just south of its intersection with Highway 97. The well was pump tested by Value Contracting. The log and construction details of the well are included in Appendix A; data from the pump test are included in Appendix B. 3. The approving authorities specify that the water system should include either a reservoir or a standby well and pump. For Phase I, the cost of a standby well and pump is clearly less than the cost of a reservoir. 4. There is a domestic water well, which is owned by the Leir Farm, located close to the Mountain Homes Well. It supplies domestic water for a single mobile home which will probably be moved away within the next year. This well was constructed in 1978 by Quality Water Wells Ltd.; its log and construction details are included in Appendix A. The well is properly completed with a well screen; it probably has a capacity similar to that of the new Mountain Homes Well. The Leir Well is available for purchase by Mountain Homes. 5. Mountain Homes can obtain an easement from Leir Farm for an additional well. 2.0 PUMP TESTING The data collected by Value Contracting during the pump testing of the Mountain Homes Well are attached in Appendix B along with plots of the data on semi-logarithmic graph paper. The data have been plotted according to standard straight line methods of analysis with drawdown... I3

5 t Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page 3 versus log of time in minutes since pumping started and, in the case of the recovery data, residual drawdown versus log of the ratio, time in minutes since pumping started time in minutes since pumping stopped. Pumping started at a rate of 4.10 L/sec (65 USgpm) which was reduced in several steps to a final rate of 3.15 L/sec (50 USgpm) at 210 minutes after the start. Pumping continued at 3.15 L/sec until 1440 minutes after the start, when pumping was terminated. The plot of the drawdown data shows the following: 1. A scattering of data points during the first part of the test; this scattering is partly due to adjustments in flow rate. 2. Following each reduction in pumping rate, the water level recovered and then began to draw down again but at a slower rate. This is reflected in a decrease in the slope of the drawdown plot for each reduction in the pumping rate. 3. At the final pumping rate of 3.15 L/sec (50 USgpm), the rate of drawdown is quite small with the final data point indicating a practically constant drawdown and a practically stable pumping water level. The plot of the recovery data shows that complete recovery of the water level to the pre-pumping static level occurs when pumping is terminated. This indicates good recharge conditions..../4

6 Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page WELL CAPACITY Under these conditions, the standard procedure in rating the capacity of a well is to assume use of 70% of the total available drawdown in the well, taking into account possible seasonal fluctuations in the water table, and to multiply by the specific capacity of the well calculated from a stable or nearly stable condition of drawdown during pump testing. With this in mind, the dimensions needed to calculate the capacity of the Mountain Homes Well are the following: 1. Top of well screen below ground m (33.58 ft). 2. Static water level below ground m (5.5 ft). 3. Total available drawdown m (28.08 ft) % of total available drawdown m (19.65 ft). 5. Specific capacity of well from pump testing at 3.15 L/sec (50 USgpm) L/sec/m (2.46 USgpm/ft). On the basis of the well dimensions given above, the capacity of the Mountain Homes Well is 3.0 L/sec (48 USgpm) at an estimated pumping water level of 7.6 to 7.7 m (25 to 254 ft) below ground. 4.0 DISCUSSION OF GEOLOGY AND HYDROLOGY The subject area is underlain by non-marine sedimentary rocks of the Kamloops Group of Upper Cretaceous.../5

7 , Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page 5 age. These rocks are essentially impermeable, but fractures carry and store a small amount of water giving the overall rock mass "fracture permeability". Wells drilled in these rocks are usually successful in obtaining a small amount of water sufficient for single domestic needs. The yield of a rock well depends on the amount and extent of fractures encountered by the hole. The small valleys in the subject area, which are cut into the rock, are partly filled with sediments deposited by or as a result of glaciers which covered the area prior to about 10,000 years ago. The sediment deposited directly by the ice is till, a very compact mixture of silt, sand and clay with scattered stones. Till is practically impermeable; however, often associated with the till are sand and gravel deposited by sediment-laden water from melting ice and these sediments are often a good aquifer. Sand and gravel of this type (overlying till) is the aquifer in which the wells on the Leir Farm, including the Mountain Homes Well, are constructed. Water in the aquifer is moving slowly through the sand and gravel downstream along the old rock valley toward the main Okanagan Valley. Wells in the aquifer intercept part of this flow which continues throughout the year. The total amount of water moving through the aquifer is likely to be much larger than the amount removed by pumping during the test of the Mountain Homes Well. This is shown by the rapid recovery when the pump is stopped..../6

8 Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Paqe 6 The actual configuration of the sand and gravel aquifer which yields water to the Mountain Homes Well, and also the nearby Leir Well, is unknown at this time. It could be a broad sheet over the width of the valley or it could be a narrow channel meandering down the valley. For this reason, there is no assurance that other wells drilled in the valley will encounter the aquifer. 5.0 GROUNDWATER QUALITY Attached to this letter in Appendix C is a copy of the water analysis carried out by CanTest Ltd. for a sample of water collected from the Mountain Homes Well during the pumping test. The water represented by the sample is a very hard water that is quite highly mineralized. It is fairly typical of groundwater in the subject area. The groundwater is a complex calcium + magnesium + sodium/bicarbonate type of water. The groundwater from the Mountain Homes Well meets B. C. Ministry of Health's British Columbia Drinking Water Quality Standards 1982 and Health and Welfare Canada's Guidelines for Canadian Drinking Water Quality (published in 1987) for all parameters checked with the exception of...i7

9 Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page 7 an elevated total dissolved solids of 575 (limit of 500 mg/l). The limit for total dissolved solids is based on aesthetic considerations in that highly mineralized waters may impart an objectionable taste to some consumers. Attention is drawn to the sodium content of 44 mg/l which may be of concern to individuals on sodium restricted diets. sample. No coliforms were detected in the bacteriological All things considered, the groundwater from the Mountain Homes Well is acceptable for domestic use. 6.0 ADDITIONAL GROUNDWATER It is often possible to predict the amount of well interference that can be expected at another well completed at a certain distance in the same aquifer. This is usually done by calculating the transmissivity of the aquifer from the pumping test data and then estimating well interference. However, under the prevailing circumstances, where the aquifer is known to be limited in extent (negative boundaries) and where recharge conditions are not clearly understood, such predictions are likely to be quite inaccurate. If another well is to be constructed, a spacing of 30 m (100 ft) is suggested to minimize interference. Obviously, the present well should be observed for interference during the pump testing of another well.... la

10 Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page 8 In this situation, it is important to begin a program of water level observations as soon as the well is put into use. Such readings should be taken on a monthly basis. 7.0 RECOMMENDATIONS From our review of the groundwater supply situation with respect to the proposed Mountain Homes Mobile Home Park, we recommend the following: 1. If possible, purchase the existing Leir Well for use as a standby well. 2. Construct an additional 200 mm ( 8" ) diameter test-production well. A site south of the existing well, along White Lake Road, is suggested. 3. Use existing wells as observation wells during future pumping tests. 4. When pumps are installed in wells, include a small diameter plastic tube to permit a water level indicator to be lowered to measure both pumping and non-pumping water levels. 8.0 SUMMARY AND CONCLUSIONS Our review of the groundwater supply situation with respect to the proposed Mountain Homes Mobile Home Park.../9

11 '. ' a Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page 9 south of Kaleden, as discussed in this letter-report, may be summarized as follows: 1. Pump testing of the Mountain Homes Well shows that the well is constructed in an aquifer that receives adequate recharge when pumped at a rate of 3.15 L/sec (50 USgpm). 2. According to standard procedures for rating well capacity, the capacity of the Mountain Homes Well is 3.0 L/sec (48 USgpm) at an estimated pumping water level of 7.6 to 7.7 m (25 to 254 ft) below ground. 3. The aquifer in which the Mountain Homes Well and the nearby Leir Well are constructed is outwash sand and gravel overlying a thin glacial till which rests on the bedrock. The extent and configuration of the aquifer are unknown at this time, but the rapid recovery of the water level in the Mountain Homes Well following the termination of pumping indicates good recharge. 4. The groundwater from the Mountain Homes Well is very hard and quite highly mineralized. It meets Federal and Provincial drinking water quality guidelines for all parameters checked with the exception of an elevated total dissolved solids of 575 (limit of 500 mg/l). The total dissolved solids limit is based on aesthetic considerations because an highly mineralized water may have an objectionable taste to some consumers. The water quality is fairly typical of groundwater in the dry interior of B. C. and is acceptable for domestic uses. 5. At this time, there is no reason to believe that additional groundwater cannot be developed from the aquifer which supplies the existing Mountain Homes Well. Based on present information, it is not possible to predict interference at a specific distance in the aquifer. A distance of 30 m (100 ft) is reasonable for another well.... I 10

12 Mountain Homes Ltd. Groundwater Supply for Mountain Homes Mobile Home Park South of Kaleden, B. C. September 28, Page The nearby Leir Well is properly constructed with a screen and, if it can be purchased, it can serve as a standby well for the water system to serve the Mobile Home Park. 7. Operation of the water system based on wells should include a management strategy based on the regular observation and recording of water levels. Yours truly, PACIFIC HYDROLOGY CONSULTANTS LTD. E. Livingston, P. ins. Attachments

13 . APPENDIX A WELL LOGS AND CONSTRUCTION DETAILS

14 MOUNTAIN HOMES WELL Location: South of Kaleden, on the south side of White Lake Road just past its intersection with Highway 97. Contractor: Quality Water Wells Ltd. Date of construction: Summer Log : o m ( o - 53 ft) black soil m ( 54-9 ft) sand and gravel, dirty m ( 9-16 ft) grey silty sand m (16-21 ft) grey silty clay, soft m (21-31 ft 1 sand and gravel, dirty m ( ft) sand with some gravel, clean m ( ft) till m (43-48 ft) bedrock. Diameter: 200 mm (8"). Depth of completed well: m (39 ft). Static water level: 1.83 m (6 ft) below the well casing stickup of approximately 0.15 m (0.5 ft) on August 12, Completion: The Mountain Homes Well is completed with 1.5 m (5 ft) of 200 mm (8") nominal diameter Johnson's stainless steel well screen with mm (0.040") slots. At the top of the assembly is a type K packer and, at the bottom, a standard bail bottom. The 1.65 m (5.42 ft) long screen assembly is set between and m (33.58 and 39 ft) below ground. A - I

15 MOUNTAIN HOMES WELL (cont'd) Well capacity: Based on a specific capacity of 0.5 L/sec/m (2.46 USgpm/ft), calculated at 1440 minutes of pumping at 3.15 L/sec (50 USgpm), and assuming use of 70% of the total available drawdown of 8.56 m (28.08 ft) in the well, the capacity of the Mountain Homes Well is 3.0 L/sec (48 USgpm) at an estimated pumping water level of 7.6 to 7.7 m (25 to 255 ft) below ground. A - 2

16 .. LEIR WELL Location: South of Kaleden, on the south side of White Lake Road just south of its intersection with Highway 97. Contractor: Quality Water Wells Ltd. Date of construction: October-November Log : m ( 0-5 ft) rn ( 5-11 ft) m (11-13 ft) m (13-14 ft) m (14-22 ft) m (22-34 ft) m (34-36 ft) rn (36-40 ft) at 12.2 m ( at 40 ft) black soil sandy gravel brown clay grey sand and gravel, dirty grey clay dirty grey sand and gravel brown sand and pebbles, cleaner brown sand and pebbles, clean grey till. Diameter: 150 mrn (6"). Depth of completed well: m (39.08 ft). Static water level: m (1.42 ft) below ground in November Completion: The Leir Well is completed with 1.2 m (4 ft) of 150 mm (6") nominal diameter Johnson's stainless steel well screen with 1.27 mm (0.050") slots. At the top of the assembly is a type K packer and, at th bottom, a standard bail bottom. The 1.44 m (4.73 ft) long screen assembly is set between and m (34.31 and ft) below ground. A - 3

17 APPENDIX B PUMPING TEST DATA AND PLOTS

18 PUMP TEST - DRAWDOWN DATA PAGE- 1 OF - 3 CONTRACTOR PROJECT Value Contracting MOUNTAIN HOMES LTD. I 12 I AUGUST I DAY I MONTH I YEAR 1 ~~~~~i~~ On the south side of White Lake Road just south of its intersection with Highway 97 Well No. 1 Pumping Rate (a) See below Datum Point Top of well casing Elevation of Datum Point Approx* 0.5 ft above ground Static Water Level 6.00 ft screen Location to 39 ft below ground TIME E LAPSED DISTANCE TIME TO DRAWDOWN HR. MIN. t (MIN.) - WATER (ft) M) PUMPING RATE (USgpm) REMARKS Static level; start pump, a8 50 B - 1

19 PUMP TEST - DRAWDOWN DATA PROJECT MOUNTAIN HOMES LTO. Well No* 1 Static Water Level 6-00 ft TIME ELAPSED DISTANCE PUMPING TIME TO OR W OWN HR. MIN. t (MIN.) WATER 4f.8 RATE ( Wpm) Stop pump. REMARKS -

20 ,..< A. _ >., ~ ~ _ ~ _ C 1 nnn

21 PUMP TEST - RECOVERY DATA PAGE 3 OF 3 PROJECT Well No. 1 MOUNTAIN HOMES LTD. 13 AUGUST I 1988 I DAY I MONTH I YEAR I ELAPSED ELAPSED TIME TIME SINCE TIME SINCE RATIO PUMPING PUMPING (tit') STARTED STOPPED HR. MIN. t (min.) t' (min.) To WATER RESIDUAL DRAWDOWN (ft) REMARKS Stop pump. 7.00

22 ~ NO. a~&uc:-ll TUlXETZbEN LRAP,? ).'AVER SEMI-LOGARITHMIC 1 CYCLES X 10 DIVISIONS PER INCH '. 1..., , I: ; L * , I..\_ I,... : I :..., , :!::::::.:::...-: I a I cn 2 - I - * - - ' -I i ' _~ i ;.... rt I:-: -: d {~...../-: :..: ,... I il-: 0 C rn _.....I... Y ::.:Is. - ~~ _ ~.. l - A 100

23 4.. APPENDIX C GROUNDWATER QUALITY

24 CanTesl Ctd REPORT ON: REPORTED TO: FILE NO: Analysis of Water Sample Mr. Phillip Locke 528 Main Street Penticton. BC v2a 5c7 2358H I'rolesslollnl Analytical Scrviccs Sllllt? WcsI 3rd Avc Vancoirver. BC V6J IJ8 Fax Tel DATE: September 6, 1988 We have tested the sample submitted by you and report as follows: SAMPLE IDENTIFICATION: The sample was identified as: PROJECT NAME: Water Quality DATE SAMPLED: DATE SUBMITTED: August TYPE OF CONTAINER: plastic for further identification, see 'Results of Testing'. SUMMARY: For the chemical parameters tested, the sample did not meet the limits set by the "British Columbia Drinking Water Quality Standards, 1982', Province of B.C., Ministry of Health and 'Guidelines for Canadian Drinking Water Quality, 1978', published by authority of Health and Welfare Canada, as indicated in the "Results of Testing". Parameters are limited for health or aesthetic reasons. The parameter that did not meet the limit was total dissolved wilds, which is limited primarily for aesthetic consideration. For the bacteriological parameters tested, the sample did meet the limits (Le. coliform bacteria was not detected). The water represented by the sample submitted may be characterized as extremely high in dissoived mineralization and hard with respect to hardness. RESULTS OF TESTING (on the following page) Don M. Enns. B.Sc.. M.6.A Assistant Manager DME/kal C:WATER c - 1

25 Mr. Phillip Locke File No: 2358H Page No: 2 SAMPLE IDENTIFICATION AND RESULTS OF TESTING: SAMPLE # CLIENT SAMPLE ID. PHYSICAL TESTS ph (ph units) Conductivity (us/cm) True Color (CU) Turbidity (NU) Hardness as CaCG3 1 KAIADEN < MAXIMUM ACCEPTABLE CONC.*** Total Dissolved Solids (mg/l) 575.x 500.* DISSOLVED ANIONS (mg/l) Alkalinity: Bicarbonate HC Carbonat e co3 nil Hydroxide OH nil Chloride a 15.3 Sulfates SO Nitrates/Nitrites N Fluorides F ~ lo.** 1.5 DISSOLVED METALS (mg/l) Calcium Magnesium Sodium ca Mg Na Iron Manganese Silica Fe Mn Si02 c0.030 c I TOTAL METAIS (rng/l) Magnesium Iron Manganese Mg Fe Mn 26.4 c0.30 c COLIFORM BACTERIA (MPN/100 rnl*r) Total (Confirmed) Fecal c1. <1. Not detected = filtered a 0.45 micron membrane *t = total nitrate and nitrite nitrogen *** = maximum acceptable concentration as set by 'B.C. Drinking Water Ouality Standards, 1982' and 'Guidelines for Canadian Drinking Water Quality. 1978' < = less than: mg/l = milligrams per litre MPN/100 ml = Most Probable Number per 100 ml sample *R = see 'Remarks' c - 2

26 *\ ' 1. c c Mr. Phillip Locke File No: 2358H PageNo: 3 REMARKS: When evaluating coliform results, the following excerpts from the "Guidelines for Canadian Drinking Water Quality, 197~ published by the authority of Health and Welfare, Canada should be noted: Page "It should be emphasized that no bacteriological analysis of water can take the place of a complete knowledge ( the conditions at the sources of supply and throughout the distribution system. Contamination is often intermittent and rns not be revealed by the examination of a single sample. The most a bacteriological report can prove is that, at the time c examination, bacteria indicating fecal pollution did or did not grow under laboratory conditions from a sample of water." Page 26 "Since the presence of any type of coliform organism in treated water suggest either inadequate treatment c contamination, the objective level for total coliforms should be no organisms detectable per 100mL; however, in practice thi level is not always attainable.' Page 27 'If anv coliform oraanisms are detected. the site should be resamded, and if the presence of coliforms is confirrnec action taken to determine the cause. If the maximum acceptable level is exceeded, the local control agency or Medical Office of Health should be contacted for the appropriate corrective action. The most common immediate actions include increasin: the chlorine dosage, flushing the water mains, using an alternative source of water and advising consumers to boil drinkin: water.' The '8.C. Drinking Water Quality Standards, 1982" published by Province of British Columbia, Ministry of Health further statc that: Page 3 'If anv raw water sarnde contains fecal coliforms or if more than fwe percent of the samples in any consecutive 30 da) period have a total coliform density greater than 10 per 100mL disinfection is reauired. METHOD OF TESTING: The analyses were carried out in accordance with procedures described in 'Laboratoiy Manual for the Chemical Analysis 01 Water, Wastewater, Sediments and Biological Materials (2nd Edition)' pubfished by the Government of B.C., Ministry 0: Environment, Water Resources Services, 1976 and 'Standard Methods for the Examination of Water and Wastewater" 15th Edition, 1980, published by the American Public Health Association. The metals were determined using inductively Coupled Plasma Spectrographic analysis, direct or graphite furnace atomic absorption spectrophotometry. c- 3