Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
0707 IYANNOUGH ROAD/RTE 28 - HOTELS/MOTELS - POOL
C©ur+ arkIMMMM _ - -- 311 - l o --- --. I i I (� I f I �� r P�pFTME Tp Town of Barnstable H O,^ * BARNSfABLE, * Board of Health MASS. 9°pp 16�9' s 200 Main Street rED MA'S Hyannis, MA 02601 Office: 508-862-4644 Wayne Miller,M.D. FAX: 508-790-6304 Paul Canniff,D.M.D. JUMC111 Sawayanagi February 29, 2008 Wendy Anderlot Courtyard by Marriott 707 Route 132 Hyannis, MA 02601 RE: Courtyard by Marriott, Lifeguard Modification for the Swimming Pool Dear Ms. Anderlot, We will allow you to employ "qualified swimmers," in lieu of the requirement to employ fully certified lifeguards, at your swimming pool located at the Courta by Marriott, located at 707 Ivannough Road, Hyannis MA. This includes persons in your pools and includes all other persons within the pool enclosure. The following conditions must be complied with: (1) The pool must be supervised by a "qualified swimmer" all times the pool is open. We wish to make it clear that this swimmer must be at the pool and cannot be observing from the desk unless another swimmer is provided and physically present at the pool. This swimmer must be certified in adult, child, and pediatric CPR by the American Red Cross, American Heart Association or equivalent, be familiar with Lifesaving equipment and knowledgeable in first aid procedures. (2) All qualified swimmers shall wear orange colored hats or orange colored visors with the words "POOL STAFF" in 15 millimeter (5/8 inch) black colored lettering on the front of the hats. (3) The maximum capacity of the swimming pool is reduced to nineteen (19) persons. (4) You shall maintain a permanent record on a form prescribed by the Board of Health listing each swimmer supervising the pool when it is in use. The attached form must be posted at the pool site in a convenient location to be viewed by the Health Inspector any time inspections are conducted. Q:\POOLS\QUALIF.SWIMMER LETTERS\Pool Modifi Courtyard By Marriott w SwimTest 2008.doc (5) You shall submit -a copy of the applicant's insurance policy naming the Town as coinsured in the amount of $1,000,000. (6) All other- regulations contained in Chapter. V, Minimum Standards for Swimming Pools, must be strictly complied with. (7) The qualified swimmers must hold a current American Heart Association, American Red Cross,-or equivalent CPR certificates with training in adult, child, and pediatric CPR. (8) The swimming pool water must be tested for coli form bacteria at least monthly by a certified laboratory. Please be advised that if you exceed this capacity of 19 -persons, your modification will be invalid and you will be required to cease operation of the pool. This modification expires December 31, 2008. It is your responsibility to ensure that you request renewal of the variance from the lifeguard requirements each year prior to opening the pool. Sincerely yours, _ G . Thomas A. McKean, CHO Town of Barnstable Public Health Division Attachment Q:\POOLS\QUALIF.SWIMMER.LETTERS\Pool Modifi Courtyard By Marriott w SwimTest 2008.doc f Town of Barnstable ABUF Board of Health 200 Main Street rED MA'S A Hyannis, MA 02601 Office: 508-862-4644 Wayne Miller,M.D. FAX: 508-790-6304 Sumner Kaufman,M.S.P.H. Paul Canniff,D.M.D. April 25, 2006 Wendy Anderlot, General Manager Courtyard By Marriott 707 lyannough Road Hyannis, MA 02601 RE: Courtyard By Marriott, Lifeguard Modification for the Swimming Pool Dear Ms. Wendy Anderlot: We will allow you to employ "qualified swimmers," in lieu of the requirement to employ fully certified lifeguards, at your swimming pool located at the Courtyard By Marriott, located at 707 lyannough Road, Hyannis, MA. This includes persons in your pools and includes all other persons within the pool enclosure. The following conditions must be complied with: (1) The pool must be supervised by a "qualified swimmer" all times the pool is open. We wish to make it clear that this swimmer must be at the pool and cannot be observing from the desk unless another swimmer is provided and physically present at the pool. This swimmer must be certified in adult, child, and pediatric CPR by the American Red Cross, American Heart Association or equivalent, be familiar with lifesaving equipment and knowledgeable in first aid procedures. (2) All qualified swimmers shall wear orange colored hats or orange colored visors with the words "POOL STAFF" in 15 millimeter (5/8 inch) black colored lettering on the front of the hats. (3) The maximum capacity of the swimming pool is reduced to nineteen (19) persons. (4) You shall maintain a permanent record on a form prescribed by the Board of Health listing each swimmer supervising the pool when it is in use. The Q:\POOLS\QUALIF.SWIMMER LETTERS\Pool Modif Courtyard Marriott 2006.doc 0 attached form must be posted at the pool site in a convenient location to be viewed by the Health Inspector.any time inspections are conducted. (5) You shall submit a copy of the applicant's insurance policy naming the Town as coinsured in the amount of$1,000,000. (6) All other regulations contained in Chapter V, Minimum Standards for Swimming Pools, must be strictly complied with. (7) The qualified swimmers must hold a current American Heart Association, American Red Cross, or equivalent CPR certificates with training in adult, child, and pediatric CPR. (8) The swimming pool water must be tested for coli form bacteria at least monthly by a certified laboratory. Please be advised that if you exceed this capacity of 19 persons, your modification will be invalid and you will be required to cease operation of the pool. This modification expires December 31, 2006. It is your responsibility to ensure that you request renewal of the variance from the lifeguard requirements each year prior to opening the pool. Sincerely yours, Thomas A. McKean, C O Town of Barnstable Public Health Division Attachment a Q:\POOLS\QUALIF.SWIMMER LETTERS\Pool Modif Courtyard Marriott 2006.doc i PAGE 03 I /2001 11:04 15087900119 I� .. 1: r �e;J J� ��.•m� 711 V 0 o l c-� 10 . I' f 12 GA. STEEL TUBING 1 1/2" fp 12 GA. STEEL TUBING 10 G�PANDED MESH 0 o r TOP 0 CURB R POOL 5 - 0 5' 0" T Y PI C AL RAILIN G ELEVATI ON SCALE 3/8 = I - 0 1 1/2" ROUND ALL OUTSIDE CORNERS WELD ALL JOINTS BUTT WELD EA. AND GRIND SMOOTH. STRAND. � 12 GA. [10 GA, EXPANDED MESH STEEL TUBING, 12 GA. - 10 GA. EXPANDED MESH, TUBIN G — CUT TO FIT OPENING AND BUTT WELD EA, STRAND TO TUBING. 0 FULL SIZE SECTION 3' - 0" v MOLTEN SULPHUR, G A T E H I NG E HASP GROUT. a TOP OF POOL DECK. 10 GA. EXPANDED MESH. OR CURB 1 112 (� 12 GA. STEEL TUBING SLEEVE v 2 1&4 POOL DECK LEVEL. OR TOP of CURB. SECTION THRU RAILING ALUM^ OR BRASS BUTT HINGES SCALE . 3/4 � = I - 0" GATE DETAIL PERIMETER WELD AND GRIND A•LL TUBING SCALE 3/811= I'-0�� POOL FENCE DETAIL — MESH TYPE william w. bo d j 81 associates STANDARD DETAIL detail architects engineers date drawn check number. 7 28/65 Tw2E ,UT w rze- revisions 148- memphis, tennessee 7/, I _ I �I �R f. e � • Swimming Pool Calculations There are several swimming pool computations that inch (psi) is the pressure created by a column of a pool/spa operator mxpt be able to perform.These water 2.31 feet high and equals 2.31 feet of head.A include the following for the size of the pool and column of water 1 foot high creates a pressure of deck: square feet; cubic feet; capacity in gallons; - .433 psi. filter size and capacity; and maximum bather load. These computations require the use of basic arith- To convert Fahrenheit (F) to Celsius (C), subtract metic and are readily available and simple to 32,multiply by 5, divide by 9;or C=5/9(F-32). calculate with the use of a pocket calculator. To convert Celsius(C)to Fahrenheit(F),reverse the process.Multiply by 9,divide by 5,add 32;or EQUIVALENTS F=%C +32. To aid in understanding the formulas and terminol- ogy used, following is a list of common terms and Metric Equivalents their equivalents: 1 meter=39.37 inches Square foot (sq. ft.) — a square 12" wide and 12" 3.2808 feet long. 1.0936 yards Cubic foot (cu. ft.) — a cube 12" wide by 12" long 1 foot= .3048 meter by 12"high. 1 yard= .9144 meter Cubic yard(cu.yd.) — a cube 36" wide by 36"long by 36"high(27 cubic feet). 1 square foot= .0929 square meter One cubic foot of water contains 7.48 gallons. 1 square yard= .836 square meter I One cubic foot of water weighs 62.4 pounds. 1 cubic meter= 35.314 cubic feet 1.308 cubic yards One gallon of water weighs 8.33 pounds. One part per million (ppm) represents 8.3 pounds 1 cubic meter=264.2 gallons I of chemical per million gallons of water. 1 gallon=3.786 liters P In pump resistance calculations, 1 pound per square 1 liter=.2642 gallons I 5 I K CHAPTER 2 — SWIMMING POOL CALCULATIONS CALCULATING SURFACE AREA Area of a circle: Calculating a pool's area in square feet is the first Example: step in determiningdata such as A=� pool gallons, maximum bather loads and others. A= 3.14 x 52A= 3.14 x 25 sq. ft. Methods used to determine surface area range in A= 78.5 sq.ft. scope from the sophisticated compensating polar planimeter to counting grid squares on an accurately scaled drawing. When possible, mathematical solu- tions based on actual measurements will yield the most accurate data, but by using the compensating polar planimeter or by .counting grid squares, the accuracy of the final result is directly affected by the 5' accuracy of the original drawing. The compensating polar planimeter is available at most engineering supply stores, but, because of its cost,buying one is not practical if it is to be used to determine the area of a single swimming pool. It can be of immeasurable value however, for high- volume work requiring area measurements on pool surface or decking areas. Geometric Formulas A simple method of calculating pool size is the use of geometric formulas. Following are basic formulas Surface Area of a Multisided Pool and calculations to determine surface area:A=Area The following examples use the basic geometric formulas reviousl p y,presented: L= Length Example 1: W=Width . Divide pool into rectangles (dotted lines). Calcu- H=Height late and total areas A,B,C. r= radius=1/2 diameter Area A= 10 x 15 = 150 sq.ft. n =pi=3.14 (a constant) Area B = 75 x 60.=4500 sq.ft. Area C=20 x 30= 600 sq.ft. m2 =area of a circle Total=5250 sq.ft. Area of a square or rectangle: 15 Example: a 10 A= LxW . . . A=3'x3' 3 A= 9 sq.ft. 3' b 60 ` Area of a right triangle: Example: A= LxW 2 45 . . . . . . . A= 6'x3' c 20 2 w 3' r 30 A= 2 fi 900 NOTE: Dividing the pool into individual areas is A=9 sq. ft. useful later when adding depth to the formula. 6 Example 2: Surface Area for. Shaped Pools 13ivide pool into rectangle triangle (dotted Mathematical for ulation of surface area may not lines). be practical for irregularly shaped or free-form pools. Calculate and total area A, B. A planimeter used by pool designers could be used Area A = 60 x 10 = 300 sq. ft. on a'set of plans that would be to scale. Generally, 2 a set of drawings with these figures should be Area B = 60 x 30 = 1800 sq. ft. available and would be more reliable for use by the operator: Total=2100 sq.ft. Surface Area of Interior Walls and Floors . . . . , . . a 10 Knowledge of the pool's actual interior surface area in square feet is helpful in estimating the quantities required for repainting or replastering a pool. If this 3o b information is not available from the pool's builder, the surface area can be calculated. Depending upon the pool's shape, depth variations and type of so construction, calculating the area can be a compli- NOTE: In this example, the area of the triangle (a) cated procedure. must be calculated as a right triangle, assuming Example 1: that the rectangular area is squared. Rectangular pool with a constant-slope bottom Surface Area of Circular Pools 40- Example 3: 20 3 Given: a 24 ft. diameter circular pool b. a Area= 12x12x3.14=452.16 sq.ft. fC - b, 6 d (724'd 12'r Area A: 3 x 20 = 60 sq. ft. Area B1:3 2 6 x 40 = 180 sq.ft. Example 4: Combine two previously learned calculations. Area B2:3 2 6 x 40 = 180 sq.ft. Area A= 20 x 20 =400 sq.ft. Area C: 20 x 6 = 120 sq. ft. Area B= 10 x 12 x 3.14 = 157 sq.ft. Total wall area = 540 sq. ft. Total = 557 sq.ft. Area D: (side view) Divide into rectangle and triangle (dotted line). Cal- ' culate length of bottom(z). 10'r b i a 20' 40 �I x 6Y . . . . . . . . . . . . . . . . . . 3 20' z i NOTE: The second.half of. circle (illustrated in I dashes)is not included in calculations but is merely Formula: x2+y2 = z2 Area A .60.0 shown for clarification of the circle area calculations. 32 +402 = z2 B1 180.0 These formulas for squares, rectangles, triangles 9 + 1600 = z2 B2 180.0 and circles are the bases for all of these geometric 1609 =z2 C 120.0 calculations, whether used individually or in combi- 40.11 =z D 802.2 jnation, to determine total surface area. Area D =40.11 x 20 = 802.2 Total 1342.2 sq.ft. 1 7 CHAPTER 2 — SWIMMING POOL CALCULAn& NOTE: Instead of using the calculations to arrive Example 1 — Constant Depth at the precise floor length, you may wish to merely multiply pool length by width. In this case, floor ao area would equal 800 sq. ft., which is only a little ---- 20 over 1/4 of 1% in variance with the actual square 4- footage. Calculating for Coved Pools Volume (V) = length(L) x width (W) x depth (D) Calculations of wall and floor areas for a pool with x 7.48 gals. walls that blend into the floor use a radius, Volume =40 x 20 x 4 x 7.48 commonly called a cove. Generally,,radii are swung Volume = 23,936 gallons from a constant spring line for that given pool. "Spring line" is the point from which a radius is Given: 1 cu.ft. = 7.48 gallons swung that causes that radius to be tangent to the vertical wall at the points of intersection. Generally, Example 2 — Variable Depth Pools the spring line is at 21/2 feet to 3 feet in residential pools and up to 4 feet in commercial pools. 1 ao• Naturally, using a radius to join walls and floor 20• 3' will create a coved area that has fewer square feet W. d, than if the wall met the floor at a 90• angle. ZI: Generally, one can expect an average residential coved pool to have a decrease in the total wall area s•d, by the following percentages: Pool Depth Approximate%of Wall Area TO"to 5'0" 17% of wall area 3'0"to 6'0" 19%of wall area Y \ TO"to 8'0" 23 to 25%of wall area > NOTE: These percentages are estimated averages D +D and will be affected by oversized deep or shallow Volume=L x W x 12 2 x 7.48 portions of the pool, increased depths or unusual 6+ 3 pool configurations. Volume=40 x 20 x 2 x 7.48 Example 1: Volume =26,928 gallons 40' 20• NOTE: Because the slope is constant from 3 ft. to 6 ft., an average of the two may be used — s' - - 1 3• i.e., 3 2 6=4.5 ft. average depth A pool seldom has a constant slope from one end to the other. To calculate volume in varying slope pools, the volume must be determined in sections Total wall area using 90° corners = 540.0 sq. ft. that do have constant slopes and added together. less cove savings of 19% _ -102.6 Example 3 — Circular Depth Pools Total surface area after cove savings are calculated = 437.4 Floor area = + 02 2 t2•' Net area of walls and floor = 1239.6 sq.ft. 31h• CALCULATING POOL CAPACITY By including depth, the cubic volume can be calculated, whether in feet, yards or meters. For Volume=r2 x n x Depth x 7.48 accurate calculations,the pool should be divided into Volume = 12 x 12 x 3.14 x 3.5 x 7.48 various areas according to depth. Volume= 11,837.5 gallons 8 Volume/One Inch in Depth Spas • Water needed for Given: Circularipa 12 ft. diameter Pool size Area of pool 1 Inch In depth h In feet In square feet (gallons) surface area 50 x 25 1250 780 Formula: User load = 10 sq.ft./bather 60 x 20 1200 750 60 x 25 1500 940 = n 60 x 30 1800 1235 100 75 x 30 .2250 1400 _ 3.14 x 6 x 6 .75 x 35 2625 1640 — 10 sq.ft. 75 x 42 3150 1970 75 x 45 3375 2110 User load = 11 persons 75 x 60 4500 2810 82 x 42 3450 2150 Swimming Pool — Public Indoor 82 x 45 3700 2300 Given: Pool — 42 ft. x 75 ft. 82 x 75 6150 3850 100 x 45 4500 2810 Formula: 105 x 45 4725 2950 User Load = surface area 165 x 60 9900 6200 24 sq.ft./bather. 165 x 75 -12375 7735 _ 42 x 75 NOTE: 1000 square feet of water one inch deep 24 contains approximately 625 gallons.. = 3,150 sq. ft. 24 sq. ft. 'able 2.1 Gallons or water needed to fill to one inch it depth is constant. User Load = 131 persons MAKEUP WATER To calculate the amount of water needed to refill the Swimming Pool — Public Outdoor pool after backwashing or as the result of splashout Given: Pool deep end — 35 ft. x 42 ft. or evaporation, measure the number of inches Pool shallow end— 40 ft. x 42 ft. required to fill the pool and apply the following formula: Formula: deep end area shallow end area (inches of water to be added) x(pool surface area in User load = 27 sq.ft./bather + 15 sq.ft./bather square feet)x(.625) =gallons of water _ 35 x 42 40 x 42 Example: 27 + 15 4 inches of water is needed to fill a pool 42'x 75'. 1,470 sq.ft. 1,680 sq. ft. 4 x 42 x 75 x .625= 7,875 gallons 27 sq. ft. + 15 sq. ft. NOTE: Refer to Table 2.1 = 54 + 112 CALCULATING MAXIMUM User load = 166 persons USER LOAD Swimming Pools and Spas — Private There are numerous formulas and guidelines estab- lishing maximum user load. Some codes consider There are no maximum bather load calculations for recirculation flow rates in gallons/minute per swim- any type of residential swimming pools or spas mer, and some differentiate between indoor, out- because they are constructed for single-family use. door, shallow and deep-end of pools. Other consid- eration is given to the size of surrounding decks or CALCULATING FILTER to special equipment, such as slides and diving SURFACE AREA boards. Pool operators-should consult the Health Codes for the appropriate formulas and to the Filter surface area is a figure that is used for all } standards for which the pool was designed. filters to determine filtering capacity and efficiency. The following are some generally accepted formu- The following examples demonstrate the steps las for calculating maximum user load: necessary to calculate filter surface area: I9 CHAPTER 2 — SWIMMING POOL CALCULATIONS .. • � r Example 1 — D.E. leaf elements DETERMINING FLOW RATE Given: 5 rectangular elements of 5 ft. x 3 ft. Example 1 — Required Flow Rate in gallons per Formula: minute (gpm) for a given turnover For one side of one leaf requirement. Surface Area= length x height Given: Pool Volume of 36,000 gallons A = 5 x 3 Required Flow Rate= 6 hours turnover A = 15 sq.ft. (one side only) (5 leaves and 2 sides= 10 sides) Formula: A = 15 x 10 Flow Rate(F.R.)= Pool Volume(gallons) A = 150 sq.ft. Turnover Time x 60(min./hour) (in Hours) Example 2 — D.E. circular elements Example: 36,000 (gallons) Given: 20 circular leaf elements, 18 inches in F.R. = 6 (hours)x 60(minutes) diameter F.R. = 36,000 Formula: For one side of one leaf. 360 Surface Area= nT2 A = 3.14 x 9 x 9 F.R. = 100 gallons per minute A = 254.34 sq. in. (one side only) y 201eaves and 2 sides=40 sides NOTE. Refer to Table 3.1, page 12 A = 254.34 x 40 Example 2 — Turnover Rate in hours, knowing 10173.6 the pump flow rate. A = 144 =70.65 sq.`ft. Given: Pool Volume of 36,000 gallons (sq.in./sq.ft.) Pump flow rate of 75 gpm (Flow Meter .Example 3 — Sand filters Reading) . ;. Given:Three circular filter tanks,6 feet in diameter Formula: . , by 4 feet in depth. Turnover(T R)_ Pool Volume (gallons) Rate Flow Rate of Pump x 60(min./hour) X (in gpm) 6 Example: T.R. = 36,000 (gallons) 75 (gpm)x 60(minutes) (In sand filters of any ,. type only the top of the T.R. = 36,000 sand surface area is cal- 4,500 culated) T.R. = 8 hours Example.3.- Filter Flow Rate Capacity Formula: Surface Area Given: Pool Volume of 36,000 gallons A = 7cr2 D.E. Filter Area of 50 sq.ft. A = 3.14 x 3 x 3 Filter Media Rate of 2 gpm/sq. ft. A = 28.26 sq.ft. (for one tank) of Filter Area A = 28.26 x 3=84.78 sq. ft. Required Turnover Rate of 6 hours Formula: Example 4 — Cartridge filters Filter Because it is pleated,the surface area of a cartridge Capacity (F.C.)= Filter Area(sq.ft.)x Filter filter is somewhat more complicated to calculate; Media Rate(gpm/sq.ft.)x however, its size can be determined by laying flat a Required Turnover(minutes). wet membrane(cartridge)and measuring its surface area. Most manufacturers specify the surface area F.C. = 50 x 2 x 360 of their product,but if not, this method can be used. F.C. = 36,000 gallons (pool volume) 10 Filters and Filtration Swimming pools and spas are subject to constant state regulations is to be able to see the pool drain contamination from foreign matter brought in by clearly from the pool deck or to see clearly a two-inch swimmers, wind and articles used in and about the disk with black and red quadrants through 15 feet water.Such contamination includes particles of dirt, of water. These turbidity standards establish only organic matter, bacteria, algae, hair, makeup, the minimum clarity allowable. The Certified Pool/ suntan and body oils, leaves, mineral residue from Spa Operator (CPO®) should strive for sparkling chemicals and other debris. clear water that offers complete visibility of the Filtration is the mechanical process of removing entire pool. this insoluble matter from swimming pool and spa Three factors that determine water clarity are water.Pool water carrying particulate matter,solids flow rate (See Table 3.1), amount of filtering area and debris is passed through filtering media that and effectiveness of filter media. allow the water to•return to the pool clear. Water clarity is important for appearance, hygiene and Tlunover Rate safety. Filters and filtering media were developed over When the total volume of a pool is filtered within a the centuries as man sought-clean drinking water. 24-hour period, the pool is described as having one Most codes and regulations were developed from turnover per day.. As the returning filtered water that research, and they provide fora range of is mixed with the pool water, it is diluted, making efficiency levels. Knowledge of the mechanics of it less turbid. (See Table 3.2). Once equilibrium is filtration is-necessary, and every operator must be achieved', a six-hour turnover will result in 98% I well qualified in them. clarification, assuming that the filter medium is effective and the filter is properly sized to accommo- WATER CLARITY date the amount of contamination introduced into Turbidity can be determined accurately under the water. laboratory conditions using photo-optical equip- Filter Area ment. The National Sanitation Foundation recom- mends that pool water turbidity shall not exceed 0.5 The rate per square foot of filter surface area that Nephelometer Turbidity Units (NTU). However, for water can be filtered varies with each filter system. short times during peak bather loading, this shall Regulations are specific as to the maximum gallons not exceed 1.0 NTU, and the pool filtration system per minute that can be filtered per square foot of shall be capable of returning this water to 0.5 NTUs filter area. In general, filtering effectiveness im- within 8 hours following this peak use. A common proves by increasing the filter area for a given method of noting water clarity described in most volume of water. l CHAPTER 3 — FILTERS AND FILTRATION • - Flow rates Flow rates Filter Media Pool m Pool (glim) Capacity 6-hour 8-hour Capacity 6-hour 8-hour The pool water flows through the filters and returns (gallons) turnover turnover (gallons) turnover turnover to the pool. As water passes through filter media, 50,000. 140 105 255 709 530 particulate matter and solids collect on the surface. 55 153 115 260 723 541 The ability of media to hold and screen fine particles 60 167 125 265 737 551 varies according to type. In general, the finer the 65 181 136 270 751 561 medium, the more successful the filtering process. 70 195 146 275,000 765 572 Diatomaceous earth, for example, is more effective 75,000 208 156 280 778 582 than sand. 80 222 167 285 792 592 85 236 177 290 806 603 Synthetic fabric in accordion folds, made into a 90 250 187 295 820 613 cylindrical cartridge, is another filter medium;'and 95 264 198 300,000 834 624 it can be manufactured to filter varied particulate 100,000 278 208 305 848 634 sizes. Many new filter media are being developed 105 292 218 310 862 645 in cartridge form.Their effectiveness and ease of use 110 306 229 315 876 655 makes cartridges increasingly popular. 115 320 239 320 890 666 Filter aids or flocculating agents, such as alum, 120 334 250 325,000 904 676 are used to complement a sand filtering medium. 125,000 348 260 330 918 687 Trapping articulate matter in the gelatinous sub- 130 362 270 335 932 697 pp g p 135 375 280 340 946 708 stance_produced by these agents improves water 140 389 291 345 • 960 718 clarity and protects the filters from buildup of 145 403 301 350,000 974 729 adhering solids. 150,000 417 311 355 987 739 155 430 323 360 1000 750 Filter Systems 160 445 333 365 1014 760 165 458 343 370 1028 770 A pool filter system consists of several basic parts: 170 472 354 375,000 1042 781 a pump and motor with a trap(hair and lint catcher) 175,000 486 364 380 1056 791 for removal of large debris; a filter to'remove and 180 500 3.74 385 1070 __802, ..trap suspended dirt;and a piping system to conduct' 185 514 385 390 1084 812 the water to and from the pool through the pump 190 528 395 395 1098 823 and filter. 195 542 406 400 1112 832 200,000 . 556 416 405 1125 844 Filters come in a variety of types,. sizes and 205 570 426 410 1139 854 configurations and can be either pressure or suction, 210 584 436 415 1153 865 or vacuum-activated. They remove suspended mat- 215 598 447 420 1167 875 ter from the pool water as it passes through the filter 220 612 457 425,000 1181 886 medium. As dirt accumulates on the filter, a 225,000 625 467 430 1195 896 resistance to flow occurs, which results in a slower- 230 639 478 435 1209 907 than-acceptable turnover rate for the pool. When 235 653 488 440 1223 917 this happens, the filter must be cleaned or the 240 667 498. 445 1237 928 medium changed or regenerated in order to restore 245 681 510 450,000 1251 938 250,000 695 520 455 1265 950 it to the original condition. This cleaning process is Table 3.1 Pool turnover rate chart referred to as backwashing, although this term is a misnomer for some types of filters. Number of Hours Percent Number of Times Pool Required Clarification days required FILTER SIZING Volume is to Filter Pool of Pool Water to' Itain displaced by Volume after Equilibrium Filter systems are required to meet Health Codes Filtered Water (turnover Equilibrium for turnover rates and.filtering capability in gallons each 24 hours period) is obtained (turnovers per per square foot of filter area. day) 1 24 42 9 Turnover 2 12 84 4 Codes require that the entire volume of pool water 4 6. 98 2 be recirculated through the filter in an established 5 4.8 99 1 time period. An accepted standard is 6 hours for Table 3.2 Clarification attained in swimming pools through consecutive public pools, 30 minutes for spas,'2-4 hours for dilution• wading pools, water parks and specialty pools. 12 ~ Calculation for achieving theaecifications has filter system ca�&. been presented on page 10. RAPID SAND PRESSURE FILTERS Filter Flow Rate The percentage of rapid sand filters (also known as A filter medium has the capacity to trap and hold sand and gravel, or anthracite, filters) being in- particulate matter, debris, oil, etc. The accepted stalled today is decreasing, but a large number of standard for each medium and filter follows within them are still in use on older and larger pools. Flow this chapter. Sizing requires using the manufac- rates for such filters are based on the surface area turer's and Health Code Standards and dividing the of the sand perpendicular to the direction of flow. calculated turnover rate by the gallons per minute per square foot of filter media. Example:A pool 42 Sand filter tanks are made in both vertical and feet x 75 feet with a volume of 180,000 gallons of horizontal configurations.Tanks maybe used singly water would require a flow rate of 500 gallons per but are more often used in banks of two, three or minute (gpm) for a six-hour turnover. A rapid sand four. They are usually selected by diameter (12 filter designed at a filtering rate of 3 gallons per inches to 10 feet) or by length (10 to 24 feet), minute per square foot of area would require a bank depending upon the system design. Some tanks are of filters totaling 167 square feet (500, gpm + 3 divided into cells by using bulkheads inside. gpm/sq. ft.)of filter surface area. A typical single,vertical rapid sand filter is shown Public-pool filter systems' must be capable of in Foss section in Figure 3.2,and a four-tank system maintaining a flow rate at its code cap acity. even is shown in Figure 3.3. Water enters the top of the when being stressed or clogged by particulate matter tank through a distributor or baffle. It is important and debris.This standard is not generally identified that the water flows evenly over the filter bed area in health codes and must be determined by the because too much flow in concentrated areas causes designer or engineer.A modern filter system would sand to migrate or to channel it. The water passes be sized and capable of meeting its required gpm through the sand and several layers of support flow rate of at least a 25%filter capacity above code gravel of graduated size, collects in the underdrain standards. A system requiring a 500-gpm rate and flows to the pool inlet piping. would be sized to filter 625 gpm to meet its code The top layer of sand, usually 12 to 20 inches standard when filters are clogged. The popularity thick, performs the actual filtering and. must be and heavy .demands on,'public, .swimming:pools . carefully selected for uniformity of size and composi- - require that the operator backwash more frequently tion. Pure silica sand, .45 to .55 mm in diameter, or renovate the filter system to offer an oversized with a uniformity coefficient of 1.5 or less, is pool balancing tank. . _filter aid Sight� glass � feeder T pump pump pressure gauge waste i soda ash acid feeder feeder strainer filter --+ filter flow heater 1 recirculation meter j pump IFigure 3.1 Cenral recirculation pattern I 13 CHAPTER 3 - FILTERS AND FILTRATION lr1, �Gl`� y' • \ J\ required for consistent results. TANK DIAM. AREA CAPACITY BACKWASH RATE Layers of rock and gravel act as a support for the Gallons per min. Gallons per min. top layer and assist flow distribution. Each layer of each tank each tank Sq.Ft. (3 gpm rate) (15 gpm rate) Iet rock and gravel is sized to support the layer nches Fe _ immediately above it. The materials used must be 30 21/2 4.91 14.7 74 inert. In other words, they must not react to 33 2314 5.93 14.7 89 chemicals. Sufficient clear space (freeboard) in 36 3 . 7.07 21.2 106,the 39 31/4 8.30 24.9 124 tank`above the sand allows it to expand during 42 31/2 9.62 28.9 144 backwashing.Freeboard should be equal'to one-half 45 . ' 33/4 11.04 33.1 166 of the depth of the top layer of sand. 48 4.- 12.56 .37.7 189 Vertical tanks have a baffle plate or other 51 4i a 14.19 42.6 213 54 4/2 15.90 47.7 238 distributor to spread incoming water evenly during 57 43/4 17.72 53.2 266 the filter cycle and to prevent sand from washing 60 5. 19.63 58.9 294 out during backwash.Horizontal tanks usually have 63 " 51/4 21.65 65.0 325 a header with holes or lateral pipes in the upper 66 51/2 23.76 71.3 357 portion of the tank to'even out the flow pattern of 69 53/4 25.97 77.9 390 the water. 72 6 : 28.27 84.8 424 75 61/4 30.68 92.0 460 78 61h 33.18` 99.5 498 Filtering Rates 81 63/4 35.78 107.3 537' 577 Filter rates for rapid sand filters vary considerably, 84 71 41.28 123.8 619 ranging from 11/2 to 5 q 87 7 /a 41.28 123.8 619 gig gpm per square foot of filter 90 71/2 44.18 132.5 663 area. For public-pool use,the most widely accepted 93 73/4 47.17 141.5 708 flow rate is 3 gpm per square foot. This rate is 96 8 50.27 150.8 754 consistent with many state and local codes for pools. 99 ,81/4 53.46 160.4 802 Filter rates for various sizes of rapid sand filters, 102 81/2 56.75 170.2 851 based on the three-gallon rate, are shown in Table 105. 83/4 60.13 180.4 902 3.3. u; 108 9 63.62 190.91 954 111 91/4 67.20 201.6 1008 114 91/2 70.88 212.6 1063 117 93/4 74.66 224.0 1120 120 10 78.54 235.6 1178 Table 3.3 Filtering rates steel baffle - _ • plate _ +� o water flow space from top o - - from pump of liner media to 30 top of baffle - -freeboard - - while alum floc _ . filter sand on top of sand - Penetrating a few inches into sand water flow gravel layers fit.'• -�to pool �., collection manifold ° surfounded by gravel Figure 3.2 Cross section of a rapid sand filter 14 I L T�CIGn8M"LorTILTno%IIv1ll . �Uc Backwas g Sand Filters ient for observrnfflocculation, sand migration or Backwashing is reversing the water flow through channeling. Filter rates were as low as 0.5 gallons the filter bed to dislodge any accumulated dirt. The Per square foot of surface area. Often, water was flow requirements for a-rapid sand filter during returned to the pool by gravity. A float-operated backwash are much greater, 12 to 15 gpm per sq.ft. _valve prevented overflow. (See Table 3.3)than during the filter cycle.To attain these high flow rates, the tanks on a multi-tank HIGH-RATE SAND FILTERS filter system are backwashed separately and succes- The high-rate sand filter(Figure 3.4)was researched sively. Each must be valved so that it can be backwashed without flowthrough to the other tanks. and developed in the 1950s. Reduction in both cost As the flow is increased, the sand bed expands and and space requirements for smaller pools motivated "boils,". producing a scouring effect similar to its development. Filter rates of 12 to 20 gpm per sandblasting. This action scrubs away all accumu- square foot of surface area created unique design lated dirt and prevents formation of mud balls . features using principles of operation similar to within the filter sand. However, if.the flow rate is rapid sand filters. too high, the supporting gravel layers may become The higher filtration rate is accomplished by influent sight ' manhole g manifold f glass from .—air vent . —' to recirculation waste pump —connections t000l gauges >: ;. l'.:.:• i return XL a: concrete subfill effluent b: coarse round gravel(8 inches deep) manifold a b c d e c: medium round gravel(4 inches deep) ` d: line round gravel(4 inches deep) ry e: buckwheat gravel(4 inches deep) f: filter sand(20 inches deep) g: freeboard(12 inches deep) Figure 3.3 View of a four-tank rapid sand filtration system dislodged or the sand washed out of the tank. using finer sands along with a controlled- As dirt accumulates in the filter bed, there is an distribution flow pattern.Entering water is directed increase in influent pressure and a resulting de- and reflected off the top of the tank to prevent sand crease in flow. These changes are noted by reading migration and channeling.The amount of freeboard the pressure gauges and flow meter.- is normally 50%of the sand depth. As the filter cycle progresses, a time is reached The lower collection system, or underdrain, must also when the desired flow rate can no longer be attained. assure an even flow pattern. Underdrains are designed with a manifold, or collection chamber, to At this point, the filter should be backwashed to which slotted, perforated or finely orificed lateral or restore it to its original cleanliness. radial arms are attached. Orifice openings must be smaller than the finest sand grains, and there must I VACUUM SAND FILTERS be sufficient area to backwash at the same rate as filtering. The backwash ratio is 1:1, while for rapid The vacuum (or gravity) sand filter is used on a sand it is 1:4 or 1:5. limited basis in swimming pools. This system of .The silica sand should be .35 to .45 mm in size filtering pool water is very effective but not efficient and have a uniformity coefficient of no greater than because of the space taken up by the filters. This 1.4. This sand is finer than that used in the rapid system is found in older, larger municipal pools. Its sand filter and, with the unique underdrain design, earlier popularity.was due to its commonality with requires no supporting gravel. A single sand-bed the filtering operation of a community's water depth of 18 to 22 inches is the reason for a much supply.The large, open concrete tanks were conven- . shorter tank. 15 1 . CHAPTER 3 — FILTERS AND FILTRATION air release to Pool pO p chambered water lorcftamOer One on p overflow distributor recvcutauon p -/ during precoat . } ` gust - \ / vrew port elements of metal screen. ceramic* of stuffy and plastic mesa(fabric) precoat feeder Over metal screen /r and pump from pool pump 10 waste backwash flow 95% Figure 3.5 Pressure D.E.filter with cylindrical elements no.20 sand .35•.45 mm Residential pools without slurry feed 21/2 gpm' `. Residential pools with slurry feed 3 gpm Public pools without slurry feed 2 gpm deep turbidity Public pools with slurry feed 21/2 gpm penetration Types of D.E..Filters concrete D.E. filters may be divided into two general ?��::::;:;.:• sublillcategories: pressure and vacuum. A pressure filter :r Fi re ;r ( gu 3.5) permits is greater flexibility in designing the filter room because it requires less space and presents more options for location.The vacuum filter manifold-lateral (Figure 3.6)can be combined with surge or balancing r underdrain tanks and is frequently Housed in a concrete or metal_tank. l Figure 3.4 Cross section of a high-rate sand filter The vacuum filter is often placed at pool deck level, adjacent to the pool. This requires no extra Flocculants for retention of surface dirt are not housing, and cleaning filters, filter operation and recommended. High-rate sand filters work on the changing septum sacs is more readily accomplished. principle of both surface and depth entrapment of Frequently, vacuum D.E. filters are set below pool solids. A coagulant would restrict filtration to the level so that their operation is aided by gravity. surface only and alter the effectiveness of this ; filtering design. D.E. Elements The elements in D.E:filterstcan be discs,flat leaves, DIATOMACEOUS EARTH FILTERS curved plates or cylinders. The'operation of diatomaceous earth (D.E.) filters The elements consist of the septa support, which IS made of metal or plastic,and the septa.Materials depends on the hydraulic placement of an extremely fine, but porous, filter medium onto a support used for septa can be woven synthetic fabric,metal , septum.The DX. acts as a microscreen that strains cloth, spaced wire or porous stone. In each case,the out insoluble particles. In many installations, addi- function is to retain the filter aid (diatomaceous tional D.E. is fed duringthe filtering earth or an expanded mineral substitute).Each type g process r keep of material has advantages in cost, filter-cake the cake porous. This process is called slurry, or body, feeding. After a time, when the filter cake holding ability, dirt entrapment or ease of cleaning. becomes clogged with dirt, it must be removed and Synthetic fabrics are used more often for septa in replaced with new D.E. D.E.filters than any other material,with polyesters and polypropylene by far the most widely used fibers An acceptable flow rate through a D.E. filter is 2 at present. Their popularity stems from their gpm per square foot. The standards established by toughness, low cost, inertness and good release the National Sanitation Foundation call for the qualities. Other synthetic fabrics, such as Dynel and following maximum flow rates per square foot for Orlon, are used,but to a much lesser degree. Some both pressure and vacuum type filters: large commercial filters are made of woven or 16 slurry feed tank float valve to and mixer maintain water level water level at least 8"above top of elements make-up water from city main air valve to blow air up through elements pool water enters"surge tank"section...overflows for backwash wall through screen to metal screen elements or catch lint and hair porous ceramic or fine- weave plastic over metal screen... h h water passes in through cake of diatomaceous y .�` from pool _ y by gravity to tank for. earth with which these % elements are coated hose recirculation �' S from during individual elements �.. ,.., .} ,f ; !chlorine precoating are removable by supply unscrewing from base wry � iL i ,• air fromcompressor r ` ' ; —. + to pool pump pulls water through elements up to 12-15 inches to waste of vacuum collection air line manifold Figure 3.8 Vacuum D.E.filter with cylindrical elements braided metal cloth or spaced wire-wound cylinders. feed pump introduces the suspended slurry into the The metal must be strong and resist corrosion. filter influent stream at a rate that will dilute the Stainless steel is the most widely used material,, incoming dirt. Most slurry feed pumps of this type with monel and•copper-based alloys, such as'brass'. -have an automatic flush system that periodically or bronze, following. Porous stone cylinders are not introduces clear water into the pumping head to used as much today as they once were because of wash out any D.E. that might settle out. With cost and cleaning difficulty. open-top vacuum filters, body feeding_can be done using a feeder that introduces measured amounts - Slurry Feeding of dry D.E. powder into the incoming stream of water. The principle of surface filtration.is involved in the typical D.E. filter. Nearly all of the solids are Precoating trapped before they have an opportunity to pene- precoating should be accomplished within a short trate the-surface of the filter.medium. Thus, if the ". period of time to produce;an even:distribution of j dirt load is heavy,.the filter will become,impervious , D.E. over the entire filtering surfaces. The amount in a short time. As .a.,means of overcoming,the of precoat necessary is in the range-.of 11h to 2'/2 problem, -body or.slurry feeding is used to ."dilute" ounces of D.E.per square foot of filter surface,or the the dirt. This process involves continuously feeding amount specified by the manufacturer. Two ounces diatomaceous earth, mixed with water, into the per square foot is the accepted measure. A one- filter influent flow in a concentration equal to or pound coffee can holds approximately eight ounces greater than the concentration of dirt being re- of D.E. moved. During the process of precoating, the light, This process may be continued until the head loss irregular diatomaceous earth particles tend to form created by the combined diatomaceous earth and a fluffy coating on the septa about 1/16" to 1/8" thick. u dirt produces a flow reduction lower than , the If the surface of the filter septum is rough with designed-for rate. many protruding fibers (such as when spun yarns Slurry feeding uses various types of diaphragms are used),the cake tends to retain its fluffy condition or displacement pumps. The D.E. is mixed in a longer.When the septum surface is smooth,the cake reservoir and kept in suspension by a mixer. The tends-to compact more rapidly; however,_it is more 17 CHAPTER 3 — FILTERS AND FILTRATION easily cleaned than when the fibers are trapped in grease are removed, a 10-to-1 dilute solution of the filter cake as in the fluffy coating. muriatic acid and may be used to remove scale.Acid, Several grades of D.E. are produced for various if it is used first, will set oil and grease, making uses. Coarse particle sizes perform best for swim- cleaning very difficult. ming pool filtration and are generally designated by manufacturers as suitable for swimming pool use. Regenerative D.E. Filters Extending Filter Runs A regenerative,or bump,filter is designed to prolong time between cleanings similar to that accomplished During the filtering process, the filter-cake pores with slurry feeding.The tubular elements are made become progressively blocked. This increases influ- 'of braided material that expands laterally when ent pressure and,in turn,tends to compact the filter shortened lengthwise. The tubes expand by means cake and reduce its permeability. Thus, as the filter of a mechanism attached to the inside. As they are cake compacts, the flow resistance increases. This shortened,the mesh opens,creating a surge of water action accounts for the shortened filter runs that that flushes the filter cake. The D.E. is then occur even when the dirt load is practically nil.High redistributed onto the filter elements. When the water velocity through the filter cake also tends to filter cake reforms, the dirt is mixed with D.E. and compact it, accelerating the blocking effect. Using evenly distributed. The regenerative process may low flow, rates, greatly extends.filter..runs, thus be done manually or automatically. helping reduce maintenance costs. Slurry feeding or body feeding is an important CARTRIDGE FILTERS means of extending filter runs. As a general rule, slurry feeding reduces the amount of precoat used. Cartridge filters have been used in residential and This allows greater space for filter cake buildup public pools since the early 1950s.�Originally, there before bridging between e adjacent filter surfaces� g surface-type were both depth-and surfac t cartridges. p e ype ca t edges. Since occurs. the early 1970s, only surface-type cartridges have been used in original equipment and for all replace- Cleaning.D.E. Filters meats. Cleaning methods for D.E. filters range -from, Surface-type cartridges have a,single layer of ,hand-rinsing the elements with a hose to pressure filter media made of synthetic nthetic fabrics attached in P backwashing and jet spray cleaning. Vacuum filters pleats to a cylindrical core.With this method,a large with open tanks are easily hand-rinsed and in- surface area can be contained in a smalls spa ce. e. spected to insure thorough cleaning. Cartridge filters have a maximum flow range of Spin cleaning the circular grid elements has been .375 to 1.0 gpm per square foot of surface area as used extensively in the past. However, there is a established by the National Sanitation Foundation trend today toward employing pressure backwash for public pools. For high-use pools and public spas, or jet spray cleaning methods. Many filters with a lower flow rate- may be required for acceptable vertical cylindrical elements are cleaned by pressure filter runs. backwashing.Sometimes,compressed air is bubbled ' . To clean: '.Stop ,pump,.—_ up through the elements to expand the cloth and shake loose the D.E. remove cartridges. 'and direct , ---" jet spray from hose to the �;L1 After cleaning the filter, disposing of the used outside of cartridges to remove - D.E.becomes a problem in many areas.A separation dirt. To remove oils, soak in tank may be used to collect the backwash, separat- trisodium phosphate (TSP). Do r.,.. ing dirt and D.E. from the water. A collector bag is not brush.After oil is removed, 5� � installed to retain D.E. and dirt, and the water is a 10-to-1 diluted solution of returned for re-use. The contents of the bag are muriatic acid may be used to discarded. remove calcium or scale if pre- �' w Even with regular cleaning,filter elements should sent. CAUTION: IF ACID IS be removed and inspected two or three times a year. USED FIRST, IT WILL SET Inspect the fabric for scale, dirt, oil and ease OILS. ems; < X � adhering to its fibers. A strong detergent, such as Flocculants are available to Nrti� — trisodium phosphate (TSP), loosens oil and grease. aid both filtration and cleaning :II' Softly brushing the elements while they are in the of cartridge filter. Do not use 1g"re 1.7 cartridge 11, with removable synthetic detergent solution aids in cleaning.After the oil and D.E.;it tears the elements. fabric elements p NATIONWIDE A ATIC CONSULTING, InaM88-833-5770 CALCULATION.FORMULAS AMOUNT CONVERSIONS DRY OUNCES TO POUNDS OUNCES = 16=_POUNDS FLUID OUNCES TO GALLONS FLUID OZS.= 128=_-GALLONS DISTANCE CONVERSIONS YARDS TO FEET YARDS X 3=_FEET METERS TO FEET METERS X 3.28-_FEET SURFACE AREAS SQUARE/RECTANGLE LENGTH X WIDTH=_SQUARE FEET CIRCLE 3.141 RADIUS X RADIUS =_SQ.FT. (RADIUS = DIAMETER=2) POOL VOLUME(GALS.) FLAT BOTTOM 5 a LENGTH X WIDTH X DEPTH X7.48=_GALLONS SLOPED BOTTOM LENGTH X WIDTH X AVE. DEPTH (SHALLOW+ DEEP =2) X 7.48= GALLONS . TURNOVER RATE VOLUME T FLOW RATE _60=3`JHOURS FLOW RATE VOLUME=TURNOVER RATE(HRS)=60 =y-00GPM S rti rat FILTER SURFACE AREA FLOW RATE FILTERING RATE=S6 SO FEET /v©qDi BTU's j wl GALLONS X 8.33 X°CHANGE= BTU's "THE FORMULA" POOL VOLUME CHANGE NEEDED (in gallons H2O) (PPM) GALLONS PPM(target -test results) 10,000 gallons — PPM (given) ;AMOUNT X X = AMOUNT LBS.j (OZS.,LBS.) PO BOX 193 NAHANT,MA 01908 www.nac4h2o.com 1 707 Route 132 Hyannis,MA 02601 COUMYMW 508/7 - 508/79090 01 0119 19 Fax 00 �g ,,,�o Aarnott 97x1S 0 Li �- /� tj 0 V P�q 3 . ,5 NHS 4 �2aC<F!C d, . ->>RECa.�► R?T HHE 0 r { -- 4q4 L , �4 \` - .,. E ! , * � I \ r � Oz CRLAN F AJ k 2 4/1+'IC YA$V \ \ ♦ \ \\\\ - - : ,,� G/g`3��11 / .`+` '� '" . J - w y , 3= 4 XEP71C 7W/1C " .,, Al'' C'yrvNFl2 T-T BACKWAS14 ` • 1��1_-.. ��>��?Wit"� �` S�C /ON f��: K1MM: S�S� O/V t� �. ( C$' N 7 -----_ ..__ _�1._� -- -- _' , , . ____�,_ ,D�, ����r-r . .,�cCT/Ov T*'ez) -',��T-1 6; T��K (tin7 r C,� � s_ �s (M o�` ,. "6 C�o Ci4LE� i _ l i i �-.r•� _._.._ .._ _-. -._ _ —"---- _.,....�._..a_..-_.__.__......_.._.,..._,...........,.,,.....:.............�_.::tt e.:a.:sw_-.-r�rr.:.-- .—t-s-...•-:ra.,..aaz»-.. ., �-. ..e._.-.r----.-.s....-..�-.._.��`_-.-___- _ s �S f Y i Mir/, � � � i,f' \„1 fin/ •/Z S4,00S .. look- I TqiI pooz f ' �Stcj/o•v -__- j� ! u I N ? LO PGA - ---` i 00 �y , � 1 � � •-_ i 1.h t�FQ. D�SC R.a i7`` w O tU I 1 f SE" of GRRa R.4•rLS o P 4•�-bDFs ztaVw/►RDS CONSTRUCTION, INC. Q. O. BOX 68 *EF-DS FERRY.. N, H. 03078 Al tv' _ - .,� ,. ._gin .: .. .•., .. �. .._ .. _. _._ .�..__.:. . ._ �_._.._.. _...._W,..,_.....,.._,..�...,p„ - ._._._._. ,