CHAPTER XIV SANITARY SURVEYS AND REPORTS (Part 2)

SANITARY SURVEYS AND REPORTS which is wound a tape measure, at the other. At the end of the tape, T, is a plumb bob, P.B., with a long point. It is allowed to fall slowly till the point touches the water surface and the spindle can then be clamped by a small set-screw, S.S. The apparatus can be lifted up from the side of the manhole and put in its case, no one but the observer knowing the water level. Another way of safeguarding this question of water level is to use a “Jones Indicator” (or glass gauge), Fig. 443, which consists of a glass graduated tube, marked in inches and decimals. This can, by means of a flexible tube, be connected to the drain plug at the lower end, and once the water is at rest in the drain, its level can be recorded and noted, a lower reading later betraying any leakage. This appliance is also useful for readily determining the fall of the drain. If the latter is filled so that the water is just half-way up in the mouth of the pipe in the upper manhole, the total fall on that length of drain will be the depth from the water level in the gauge to the centre of the drain plug below it. Another use for the glass gauge is to ascertain the approximate position of a leakage if it exists. When there is no longer any lowering of water in the gauge, the height of water level above invert of manhole is read (say 15 inches) and horizontal distance back to the leakage can be calculated by proportion, if the gradient of drain is known. For a drain laid at #4 with the indication assumed above of 1-25 feet the distance 40 a From which distance = 40 x 1-25 = 50 feet. A variant of the glass gauge is the “bucket gauge” in which a metal canister or “ bucket” to hold about a quart of water replaces the glass tube. This can be used for completing the filling of an unfinished length of drain at its upper end, while the glass gauge indicates water level and leakage at the lower end. During testing, the plugs should be from time to time inspected to see that they are not allowing water to pass them. Another method of applying the water test is to attach a short length of 1}-inch pipe to the plug by means of an elbow or bend, having inside it a small bore pipe to permit of the escape of air as the water enters the drain. The water can be allowed to rise in the pipe nearly to the top, and the depth of the surface below the top can SANITARY SURVEYS AND REPORTS 441 be measured and noted. If there are no manholes, the ground must be opened up at both ends, for the purpose of inserting a plug at the lower end, and of connecting a vertical bend at the upper, in which the water level can be noted. It is by no means a common practice to test the length of drain from the interceptor to the sewer, but this can be readily done by floating a bag plug through the interceptor, attached to a wire or cord, and then inflating it. This length of drain should be as watertight as the remainder of the system. This possibility of floating the bag plug along the drain and then inflating it is a matter of very great value, for, by it, one is able to localise a leak in the system. Knowing that any length is leaking, float the plug down for a length of, say, 10 feet and then test that short length. If that is satisfactory, deflate the plug and float it on for, say, another 10 feet, and again test. This advantage is not, of course, attached to the use of rubber ring plugs, which can only be used near at hand. It is a common practice to test soil and vent pipes by means of the water test, though it is considered too severe a test by many sanitary engineers. In passing new work it should certainly be done, but a smoke test under pressure is, by some authorities, regarded as sufficient for pipes which have been standing some years. The arguments in reference to the fairness of the water test for old drains also apply to this case. The application of the water test is essentially a matter for a fine day, as in wet weather there is danger of rainwater finding its way into the drain. During the testing of any drain care should be taken that the sanitary fittings are not used, for the same reason. The air or pneumatic test is one of which the merits have been much urged in recent years by the opponents of the water test. It applies a uniform pressure to all parts of the drainage system, but that, as already pointed out, does not indicate what happens if a drain becomes blocked at its lowest point, when the pressure to which the drain is subjected by nature is one which increases with the depth of any point below the free surface of the accumulated sewage, The test is applied by closing all openings on the system and pumping in air by means of a small pump to which a pressure gauge is attached. Ifthe traps on the system are not also plugged, no appreciable pressure can be applied, since a pressure of about 0-036 Ib. per square inch on 1 inch of water will be liable to upset the equilibrium of the water seal. If the traps are plugged, any desired pressure can be applied. 4.42 SANITARY SURVEYS AND REPORTS Reasonable Pressure for Testing. It is generally accepted that stoneware pipe drains should safely stand a pressure of 3 lb. per square inch (about 7 feet head of water), while properly con- structed iron drains should safely stand 10 Ib. per square inch (about 23 feet head). The air having been pumped in to a pressure of, say, 3 lb. per square inch as indicated on the pressure gauge, the tap of the pump is closed. Any decrease in pressure recorded by the gauge will indicate leakage, but it will be seen that the method does not give good facilities for localising any leakage. The chief argument in favour of the air test is that air can get through defects which water cannot penetrate. Drain Mirrors. Other appliances used in the testing of drainage are drain mirrors and electric lanterns. In inspecting a straight length between two manholes, a mirror may be placed in one of the manholes, and the small electric lantern in the other. The mirror is on a stand like an easel, and, if set up at a convenient angle, the observer can, by the aid of the light, note the internal condition of the drain by looking down into the mirror. The effect should be like looking through a tube. If the lantern is a powerful one, its light will be strong enough to illuminate the drain round a slight bend, in which case, although the reflection of the globe containing the light cannot be seen, there is sufficient illumination of the interior of the drain to permit of its interior condition being noted for an appreciable distance from either end. Need for Periodic Testing. A drainage system requires main- tenance in just the same way as any other part of the habitation, although this is a fact which is largely ignored. Any system of drainage should be regularly inspected and tested, say about every two years, We now come to the procedure in making a complete sanitary survey. Arrangements should be made for the surveyor to be met on the site by a plumber, or preferably a plumber and a labourer, to act as assistants. In London some of the large firms of sanitary engineers keep men who are experienced in this particular work, and send them out with all the necessary apparatus to assist sur- veyors. The expense is inconsiderable, and the value of an assistant accustomed to the work is great. Need for System in Sanitary Surveys. Having arrived at the site, the surveyor should first make a preliminary and cursory examination of the exterior of the house, and its surroundings. Having done so, he is in the position to instruct his assistant as to the removal of manhole covers, opening up the ground where SANITARY SURVEYS AND REPORTS 448 necessary, plugging the drains, applying the tests, and so on. While this is being done, he is free to turn his attention to the inside of the house until called out by his assistant in reference to points incidental to the tests. Nothing is more important than that he should be systematic in his inspection. It matters not whether he starts at the top floor and works down to the basement, or vice versa. The Survey Notebook. Let us assume that the inspection to be made is that of a fairly large house with a basement, and that he intends starting at the lowest floor and working upwards. His notes should be made in a systematic way in proper notebooks kept for this particular purpose. Special books are obtainable, with the various headings printed in, and with sheets of squared paper at intervals for the purpose of making sketch plans, but plain notebooks are better, as no printed notebook can give all the headings likely to be required for every possible case. Having entered the descriptions of the property and the date. the surveyor should proceed to the basement and take notes of all matters coming under the heading of sanitation at this level before proceeding upwards; as to items which are satisfactory his notes need only be the briefest description, but unsatisfactory items should be noted in detail. As he deals with each room he should have regard to its lighting, ventilation and signs of dampness, if any, and locate the cause. He should look for gullies in the floor, making a careful search, and having any lumber removed in order that he may do so. The Water Closets. If the room contains sanitary fittings they should be thoroughly inspected; if quite satisfactory the only note necessary is, say, ““W.C. quite satisfactory”, but before making such a note regard should be had to all the following points: floor, walls, type of apparatus, its condition and cleansing proper- ties, trap, its form and condition, means of flushing, capacity of cistern, condition, ball-valve, overflow, flushing pipe, etc. together with all the joints around the apparatus and cistern. Sinks. In the case of a sink, the surveyor should have regard to its material, condition, trap, waste pipe, point of discharge and its situation as regards light; also the nature and condition of the water fittings supplying it. Having gone through the basement in this way, he should then go to the ground floor and follow a similar procedure; then on to the upper floors, each floor being completed before another is commenced. At the top of the building cisterns will usually be found; the surveyor should have regard to their situation, accessi- 444 SANITARY SURVEYS AND REPORTS bility, lighting, ventilation, material, capacity, condition, con- nections, overflows and all other details. Hot-water Service. The hot-water service should not be over- looked and, unless satisfied that the service is efficient and suffi- cient, the matter should be settled by lighting the fire and noting the time taken to get hot water and the approximate temperature obtained. Cold-water Supply. Enough has been written, no doubt, to indicate the general manner of proceeding, but special features will frequently occur. Thus, if there is any reason to doubt the quality of the water, samples should be subsequently taken in the manner previously described. If filters are found, they should comply with the requirements laid down herein for a satisfactory filter. Testing the Gas Supply (if any). If gas is used in the house, some sanitary surveyors make a practice of testing the soundness of the gas piping. This is done by a small machine consisting of a pump, pressure-gauge and safety-valve. The pipes should stand a pressure of about 2 lb. per square inch, the method of applying the test being as follows: Shut off the gas at the meter, and connect the pump to a gas bracket by means of a flexible tube attached to the machine. Pump until the gauge registers the desired pres- sure; the finger of the gauge should then remain stationary. Should it not do so, the leakage can be traced by putting a small quantity of liquid ammonia in the machine and proceeding in the following way: Open the tap of a gas-fitting, preferably the farthest from the meter, to allow the air to escape, and then pump the fumes of the ammonia into the pipes. If a chemically prepared paper is then passed along the pipes, the ammonia fumes which are escaping at any leak will change its colour. Exterior of House. On completing the inspection of the interior of the house, attention must be given to the exterior. Should there be an open area, one must have regard to the condition of its paving and to the facilities for draining it. If there be an ordinary timber floor to the room inside, note the provision as to air bricks for the ventilation of the space below it. In the case of non-basement houses one often finds air bricks blocked up by the banking up of flower beds, or formation of rockeries. The con- dition of the walls as regards evidence of dampness; of the roof as regards cracked or broken slates or tiles, defective gutters or flashings, and of the eaves’ gutters as regards the necessity for cleaning out, all should be dealt with. Waste and Soil Pipes. Next examine the waste pipes on the 446 SANITARY SURVEYS AND REPORTS 116, AIREDALE GARDENS. S.W. BUTLER'S SERVANTS’ BANTRY HALL -~--- PROPOSED DRAINS. SCALE OF FEET FK.T-FLUSHING TANK. Y¥.G.- YARD GULLEY. S-Soit PiPE VP -VENTILATING PIPE. a a x “ = < ™N ag x z DG : Q l = Bs zy =< x Q «& oN 2 § @ § <x Fe ! & Y | 9 x S - x rs REFERENCE : F.G -FLUSHING GULLEY UNDER PAVEMENT DRA/NAGE AND BASEMENT PLAN SANITARY SURVEYS AND REPORTS 447 If any alterations are to be suggested, the approximate dimen- sions should be figured on this plan. In many cases the courses of the various drains will be fairly obvious from the inspection of the manholes and a comparison with the positions of the gullies and other features, but in any case of doubt the course of the drain should be traced by pouring coloured liquid through the gully or fitting. The water may be coloured by adding whiting, or cork dust of various colours is obtainable for the purpose. The length of drain from the interceptor to the sewer should be tested, or, if there is no sewer, the cesspool should be carefully examined and notes made of any defects or objectionable features. Sufficient has probably been given under this heading to indicate the general course of procedure as to the external inspection. Example Sanitary Survey. The following example shows the notes which might be taken when making a sanitary survey of a good-sized house, using an ordinary notebook, and assuming, for convenience, that plans of the building and its drainage are avail- able. The plan of the basement and its drainage is shown in Fig. 444, in conjunction with the report on the matter, SANITARY SURVEY OF 116 AIREDALE GARDENS, S.W., FOR C. Jones, Esq. 127rH SeprEMBER, 1954. INTERNALLY. Basement. Well lighted and ventilated. No internal gullies. Internal r.w. pipe at back of central staircase. Iron shoe at foot with screw-down cover in good order. Servanis’ Hall. White-glazed sink, cracked; grating outlet. One and a quarter inch lead waste discharging into trap of B.P. Sink near by. Waste blocked. H. and C. supply. C€.W. tap wants new washer. Butler’s Pantry. White-glazed sink, sound; plug outlet and overflow. Lead covered draining board. One and a half inch lead trap and waste through wall and over guily. H. and C, supply. Taps in good order. Scullery. Two white-glazed sinks side by side, badly chipped and worn. One with plug outlet and overflow, other with grating. One and a half inch lead wastes, one discharging into trap of other. Waste through wall and over gully. H.W. taps want new washers. Knife House. Draw-off tap in good order, no drip sink but cement floor with good fall to doorway. Servanis’ W.C.’s. One adjoining area steps. Hopper pan and 448 SANITARY SURVEYS AND REPORTS trap, latter broken. Seat badly broken. Two gal. W.W.P. in good order but handle missing. Other, near by, pedestal wash- down, broken. Seat has balance weights, which have been cause of breaking pan. Two gal. W.W.P. in good order but handle missing. Cement floors to both, good windows, and ventilated by space below door also. GrounD FLoor. Cloakroom. White glazed tip-up lav. basin. One and a quarter inch lead trap and waste through wall and over gully. H.andC. supply. Taps in good order. W.C. adjoining. Wash-out apparatus, dirty condition. Dished marble safe, no waste pipe. Two gal. W.W.P. in good order. Well lighted and ventilated. First Froor. W.C. Exactly as last, otherwise in good order. Bathroom. White porcelain bath. Fixed enclosure, pol. mahog. top. Lead safe under with W.P. through wall. Two-inch lead trap and waste through wall and over hopper head. H. and C. supply—taps in good order. Draw-off tap beside bath, with lead-lined drip sink under waste through wall, all in good order. White glazed lav. basin, weir overflow. One and a quarter inch lead trap and waste through wall and over hopper head.