VALUABLE RUBBISH

Evening Post, Issue 25, 30 January 1935, Page 12

VALUABLE RUBBISH

FILLING UP GULLIES

BRADFORD SYSTEM

WELLINGTON TIPS

,An outline of how. house.refuse may be used to fill in gullies, and transform otherwise valueless land into areas suitable for building sites, play areas, or flower gardens, was given by Mr. A. W. Brayshay, Assoc. M.lnst.C.E., in an address delivered today to the conference of the New Zealand branch of the Eoyal Sanitary Institute. The title of the address was "Kefuse Disposal by Tipping," and Mr. Brayshay reviewed this system, more commonly known as the Bradford system, as, it is applicable to "Wellington. -

Tipping meant the disposal of refuse which had been collected from different sources and conveyed to ono or more places and there left finally to Tot, said Mr. Brayshay. If the refuse was covered with spoil, and the depth and area definitely limited, it was known as controlled tipping, of which the Call system, popularly known as the Bradford system, was the best modern example. If the refuse was just tipped and left, the depth of face and area depending only on time and amount, the method was known as uncontrolled; it was an oyesore, a menace to health, a breeding ground for vermin and flies, and a danger froto fire. Uncontrolled tipping should be discouraged.

Quoting from "Modern Public Cleansing," Mr. Brayshay said that . the Eomans were very particular in regard to - public cleansing. Scavengers and carts were employed on contract, and [the' refuse was removed and used for agricultural, purposes. The Jews, also, under the Mosaic law, were very particular, and were enjoined to remove everything offensive or putrescible to a place well beyond the city or camp. Further, they had to be responsible, personally, that the refuse was carefully covered with earth.: "It is said that an engineer visiting Wellington about three years ago, when, told that-: the new Bradford system had recently been introduced to the city, remarked, 'Newt It's the system Adam and Eve used.' "It may be," said Mr. Brayshay, "that he had the Mosaic law in mind." . . {

After the fall of the Romans and up to and through the Middle Ages, cleanliness went out of date. Refuse was tipped anywhere and anyhow: in the yards adjacent to the houses, in the streets, even in the churchyards, - and then cleared only when the heaps became an almost impassable barrier to traffic. That state continued, more or less, up to 1855,; when an - Act was passed, for London, requiring the local authorities to remove and dispose of refuse. It was probably then that the uncontrolled tips were started. Those tips certainly relieved the streets and the people, but grew to such proportions that they became a menace to the country surrounding them. :

"JAM TIN GULLY" ONWARDS. - Refuse disposal-in. Wellington in the early days was, effected by tipping in the nearest convenient sandhills. The next move was the v establishment of the John Street uncontrolled tip, later known as "Jam Tin Gully," which appeared to have been in use for-fifty years or more. About forty years ago the.first destructor was built, and "Jam Tin. Gully" became more of • a metal and tin tip. In ; 1928 its use was discontinued. The tip was covered with spoil, the rats exterminated, and the smells smothered. The Winter Show buildings and grounds occupied part of the old tipping area. '. .

• Mr.' Brayshay reviewed the visit to England of Mr. L. S. Drake, Chief Traffic Inspector, ■Wellington, in 1930, and his discussion with Mr. Call, Director of Public Cleansing, Bradford. Mr. Call evolved the system of refuse disposal known as the Bradford system and placed all details before Mr. Drake. On the latter's 'reurn, a. Teport was presented to the City Council, and following that report the power-driven masticator at Rongotai was closed down arid a start was made in controlled tipping.

Sites were chosen at Central Park, Lyall Bay, Island Bay, Karori, and Ngaio. The refuse was taken from the districts in the. vicinity, dumped in layers, consolidated, covered with spoil, and a battered face kept. The tins were placed at the bottom, of the face, and the larger ones filled with spoil. : One of.the private tips, at Karori was completed and handed back to the owners within about twelve months, the section considerably improved,in value.

RESULT OF EXPERIMENT. \ Fourteen months after the initiation of controlled tipping, a report was made to the City Engineer. It was found that the principal obstruction to efficient tipping was the destructor, which supplied steam for pumping purposes, and therefore required fuel. Coal was too costly, and consequently only the surplus refuse not wanted at the destructor was available for tipping. It was alsoi found that the ash content of the refuse was insufficient for any practical1 covering, and spoil had to be carted to provide enough cover. Trouble was also encountered in one tip owing to the marshy character of the ground. However, the pioneering work had been done, and it showed the possibilities of controlled tipping,in Wellington.. After the closing of the John Street tip, sites had to be found for : tipping old iron»and steel—mainly trade Tefuse,; and two uncontrolled tips were started: one at Maranui, and the other at Chaytor Street,1 Karori. The Maranui tip had a face of 20ft, and the Karori tip a face of 60ft. Both tips were infested with rats, and outbreaks of fire in them were not unknown. No outbreak of fire had occurred at a controlled tip. A reorganisation of the service took place, and it was decided that owing to the demands of the destructor it would be more efficient to reduce the number of tips so as to employ the tip men full time. It was also decided, as fars as possible, to use Corporation property. The private property tips were finished and handed back to their owners. The Maranui uncontrolled tip was converted into a controlled tip, and to date, approximately 13,288 cubic yards of refuse had been tipped there. The present tip area would be completed in about six months. The Central Park tip had been continued, and should be completed about July next.

AN ADAPTATION. ■ A local adaptation -was made at the Karori tip. It was considered a very suitable tip for house refuse, provided a start could be made at the bottom in the orthodox Bradford manner. The gully was 70ft deep, 300yds long, '50yds wide, and one side was composed of filling.. There was no access, t and a road to the bottom. was not feasible. The difficulty was.overcome by building a covered chute, with an enclosed tiphead, with a controllable door at the lower end to hold the refuse. Two tipping trucks, arranged to work mainly by gravity, convoyed the refuse to the face, and cover was obtained from the side. Tho tip had a capacity for thirty years. Mr. Brayshay said that the calorific value of honsc refuse was rapidly decreasing; tho weight per cubic yard was decreasing, and the average cubic content of tho individual collection was materially increasing. That was

easily accounted for. Gas and electricity had replaced coal for heating and cooking, and' consequently there were few cinders or ash. People were using enormous quantities of tinned food, and tins were bulky. It had to be remembered that a destructor plant designed twenty-five years ago to produde a given amount of steam by burning a given quantity of refuse, must, if tho calorific valuo of the refuse dropped by 50 per cent., be unable to produco the originally-given amount; that was a strong argument in favour of controlled tipping. In the period June 1, 1931, to December 1, 1934, in Wellington, 20,381 tons of house refuso and 1646 tons of trade refuse had been buried. It was estimated that 700 to 1000 tons per ■annum more could have been dealt with without much—if any—additional cost, but the demands of the destructor had prevented that. "The destructor has become very selective,'' said Mr. Brayshay. "Paper, for instance, blows out of the chimney and annoys the people living in the vicinity; so paper goes to the controlled tips. There are other similar instances."

IMPROVING THE LAND. Mr. Brayshay said that the improved value of the land after tipping was completed should be taken into consideration when assessing the cost, which averaged 5s 9d per ton. On a completed tip at Island Bay a house was now built. Tho section, prior to tipping, was practically valueless; certainly a house could, not have been built there.

Flies were less evident on a wellcontrolled tip than elsewhere, because every effort was made to get rid of them, and the tips were treated daily with an effective solution. Uncontrolled tips were congenial homes for rats, but the controlled tip was a different matter. There were no voids for nesting-places; rats would not burrow in a moving face, and the remainder of the tip was of too high a temperature for an animal to live in. To kill smells, the area was liberally sprayed nightly. After a few days it had been found that the temperature of the refuse would rise, and would reach: a. maximum of about 140deg F. Temperature fluctuated according to moisture. It fell in dry; weather* and rose in wet. It might 'be supposed that after eighteen months the bacterial action had practically effected the purpose of reducing the conglomeration of material down to earth. "The actual manurial value of house refuse may not be much," said Mr. Brayshay, in conclusion, "but the mechanical effect, after the refuse has rotted back to earth in the form of improved drainage to the surface soil must be material. The flower-gardens made in Bradford on completed tips are proof."