H ; —34.

and was taken to 160 ft. The first 50 ft. was in clay formation, followed by 4 ft. of hard blue shingle tightly packed with a minimum of sandy matrix and then papa to the bottom of the hole. The bore-hole supplying the dairy factory is sunk on a terrace remnant 70 ft. above sea-level a few chains south from the factory. It is 225 ft. deep, 3 in. in diameter, and is cased to a depth of 80 ft. Pumping for eight hours daily provides a supply of excellent water ample for all purposes. No log is available, the only information obtained being that 8 ft. of hard rock was drilled through in some part of the well. This hard rock may be a strongly calcareous layer interbedded in the Tertiary claystones that are exposed along the shore between the factory and the wharf and that the bore must have penetrated before reaching sea-level. If the hard rock is at the bottom, the bore has probably reached the underlying Mesozoic strata, indurated rocks with many partings much more likely to yield water than the overlying impervious Tertiary beds. The low temporary hardness due to the presence of calcium salts also suggests that the water from the factory bore is derived from the non-calcareous Mesozoic rocks rather than from the lime-bearing Tertiaries. Mr. K. M. Griffin, of the Auckland Scientific and Industrial Research Laboratory, examined samples of water the Health Department collected from the spring and the bores. He reports that the water from the spring is of good quality, that the hotel bore yields water too high in iron to be suitable for domestic use, and that the ammoniacal nitrogen in the water from the factory bore suggested surface pollution and that the chlorides were rather high. The total (and temporary) hardness of the three waters was respectively 7-0, 6-5, and 3-0. According to the Acting Dominion Analyst, ammoniacal nitrogen in water from deep bores does not necessarily indicate surface pollution. There seems then to be two possible sources of water for domestic use at Raglan —the Waipatukahu Spring and water from bores into the underlying Mesozoic rocks. A supply from the spring involves the cost of bringing the water to some convenient point in or near Raglan or distribution. If water is to be obtained from the same source as tapped by the factory bore several points must be considered. The capacity yield of the factory bore is not known ; eight hours' daily pumping at an undetermined rate is sufficient to supply all the water required in the engine-house and in the factory. That the water is derived from the Mesozoic rocks underlying the Tertiary beds is highly probable, but this point must be established beyond doubt. If this is the source it is not likely that all parts of the great thickness of Mesozoic beds, which range from indurated claystone through strong sandstones to massive conglomerates, will be equally productive. Again, some parts more strongly folded, shattered, or otherwise deformed may have a much greater induced porosity than other parts. The bore near the factory may be in a particularly favourable position. If this source is considered for the town supply, the first thing to be done is to ascertain the capacity of the factory bore ; if the yield is satisfactory another bore should be sunk in the same locality to the same horizon and similarly tested.

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