This Act necessitated a revision of the regulations relating to appointments of Sanitary Officers, and on the 28th March, 1922, the Sanitary Officers Order, 1922, was issued to take effect from the 1st April, 1922. This Order relates to Medical Officers of Health appointed by County Councils, Local Sanitary Authorities and Port Sanitary Authorities, and to Sanitary Inspectors appointed by Local Sanitary Authorities and Port Sanitary Authorities. It rescinds all the existing Orders relating to these officers and re-enacts with modifications certain of the provisions of those Orders. The Sanitary Officers. (Tenure of Office) Order, 1921, which is among the Orders rescinded, was issued on the 12th April, 1921, before the Public Health (Officers) Act was passed. It gave increased security of tenure in the case of future appointments of whole-time officers. The Public Health (Officers) Act applied to all appointments, future and existing, and rendered the Order unnecessary.

The chief alteration of substance in the new Order is that it prescribes for the first time (by Article 16) a qualification for Sanitary Inspectors outside London, namely, the certificate of the Royal Sanitary Institute or of the Sanitary Inspectors Examination Board. By Article 5 it extends the qualifications to be required of all Medical Officers of Health by the addition of a diploma in sanitary science, public health or state medicine, or three years experience of the duties of the office. Under Article 21 the Minister may dispense with these requirements where it appears to him desirable to do so.

WATER SUPPLY.

The Deficiency in Rainfall.

The past year has been one of much difficulty as regards water supplies owing to the prolonged drought. The effects of this have been variable, but over the whole of England and Wales, except in the vicinity of the Lake District of Cumberland, the rainfall has been much below the normal. The shortage has been most acutely felt in the southern, and especially the south-eastern, counties, where the rainfall during 1921 was in some parts only half the average amount. In this connection it must not be overlooked that the south-eastern counties are those in which the average rainfall is the lowest in the country. It was not until January, 1922, that any appreciable break in the deficiency of rainfall was experienced. Moreover, the excess of warm weather materially added to the effects of this deficiency by further reducing by evaporation the amount of percolating water from which the underground sources of supply are fed.

Some interesting information has been reported by the Superintendent of the British Rainfall Organisation as the result of observations at Rothamsted, near Harpenden, and Grayshot, near Haslemere. These give 5.98 and 5.69 inches respectively as the total amount of rainfall passing through three feet of natural soil during 1921. At Grayshot the percolation was 1.64 inches from February to May inclusive, after which no percolation was recorded. At Camden Square, London, the total evaporation during 1921 from a free-water surface was 19.69 inches, being 5.09 inches in excess of the total rainfall.

Steps taken to meet the Deficiency.

In the course of last summer it was decided to hold a series of conferences to consider the best means of securing a more systematic investigation and a wider knowledge of the various methods in use for treating water so as to render it suitable for potable supply purposes, both in times of emergency and in ordinary circumstances. In addition to the official members, Sir Alexander Houston, K.B.E., C.V.O.; Dr. W. A. Bullough, M.B., D.P.H.; Mr. F. W. Davies, M. Inst.M.E.; Dr. W. H. Hill, M.D., D.P.H.; Mr. L. Holme Lewis, M.Inst.C.E.; Mr. Raymond Ross; and Mr. F. W. Macaulay, M. Inst.C.E., kindly consented to attend and to give their advice and assistance. These conferences have proved of much value to the Department.

The shortage of water having rendered it necessary to consider the possibility of utilising sources of supply not ordinarily used for potable purposes, the question of the effective treatment of such supplies in order to render them safe became of importance. It was therefore decided to inform Local Authorities of the best means of securing sterilisation by treatment with chlorine, and accordingly a circular ́letter was issued to them on the 15th September, 1921.

The effects of last year's drought may in some districts continue to be felt for some little time owing to the depletion of underground sources of supply and the length of time required for the restoration of these supplies by percolating water. It has therefore been considered desirable to warn Water Authorities whose supplies may be affected of the importance of curtailing the undue use of water and of being prepared betimes with definite plans for supplementing supplies which may be liable to failure or to serious diminution.

Report of Water Power Resources Committee.

During the year the Water Power Resources Committee made their Final Report, which has been issued as a Stationery Office publication. One of their recommendations was that an Inter-Departmental Committee should be appointed to secure co-ordination between the Government Departments interested in the various aspects of the water problem. Such a Committee has recently been constituted.

The Department have also taken in hand the work of collecting and indexing particulars of the potable supplies of water and the water resources of the country on the lines suggested by the Committee, and the opportunity presented by last year's drought was taken to ascertain from the Water Authorities-both Water Companies and Local Authorities-the yield of the various sources of potable supplies under normal conditions and in a year of drought. A large number of Water Authorities have furnished information as to :

(a) the average yield in 24 hours in 1920,

(b) the minimum yield in 24 hours in 1920, and

(c) the minimum yield in 24 hours resulting from the drought. The Department have also collected much other information. during the past year; and, in particular, advantage has been taken of any visits paid by the engineering staff in the course of their ordinary work to amplify the information already obtained of the water resources of the locality. The information so far collected is of considerable interest, and it is hoped that the records will in due course be available for many public purposes.

Metropolitan Water Supply.

The drought was severely felt in the Thames Valley.

The average natural flow of the Thames at Teddington Weir in the year 1921 was 712.6 million gallons daily. Of this quantity 161.8 million gallons daily were abstracted by the Metropolitan Water Board, while a further 2.9 million gallons daily were taken by water companies. From May to December inclusive the natural flow averaged 322.3 million gallons daily, but fell as low as 205.1 million gallons in July.

During the months of July and August 80-7 and 65-6 per cent. respectively of the natural flow was taken for water supply purposes.

The average natural flow of the Lee at Feilde's Weir during the year 1921 was 57.4 million gallons daily; 21 4 million gallons daily were abstracted by the Water Board above this Weir, and a further 19.4 million gallons below. The average daily flow of the river at Feilde's Weir ranged from 128.8 million gallons in January, 1921, to 14.1 million gallons in August.

The average daily quantity of water supplied directly to consumers during the year 1921 from various sources was :—

154,254,500 gallons from the Thames (60.98 per cent. of the total quantity supplied);

45,425,800 gallons from the Lee (17.95 per cent.);

53,099,600 gallons from springs and wells (20.99 per cent.); 94,500 gallons from the Hanworth gravel beds (0.04 per cent.); 95,200 gallons from ponds at Hampstead and Highgate (0.04 per

cent.).

In addition a further 1,931,400 gallons were supplied in bulk to adjacent water undertakings, of which 1,719,200 gallons were from the Thames and the remainder from wells.

With a view to preventing the undue consumption of water, the Department in June last addressed to the Metropolitan Borough Councils and other Sanitary Authorities in the Metropolitan Water Board's area a letter urging that the use of water for public purposes should be restricted.

As the result of measures taken by the Metropolitan Water Board to reduce the pressure in the mains during the night in various districts, and to curtail the use of water for street watering and other public purposes, and for gardens, very considerable economies were effected.

Posters were also issued calling the attention of consumers to the imperative need for the prevention of waste or undue consumption of water, and pointing out that waste is a punishable offence.

The total number of separate premises supplied at the end of the year 1921 was 1,140,849, and of this number 99 per cent. were on the constant system.

Upwards of 1,000 samples of water are examined chemically or bacteriologically each month and, despite the drought, a high standard of purity was maintained.

Water Charges.

During the year covered by this Report the Water Undertakings (Modification of Charges) Act, 1921, was passed. This Act provides that the Minister may by Order modify the provisions regulating the water charges in a district, in order to meet any increase in the cost

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and charges of carrying on the undertaking attributable to circumstances arising since the 4th August, 1914, which were beyond the control of, and could not have been reasonably avoided by, the undertakers. The Minister may also by Order modify the provisions of any award or agreement which determine the price to be charged for the supply of water or for any fittings, materials, or service in connection therewith.

In pursuance of the Act, rules were made by the Minister on the 7th October, 1921, with respect to applications and other proceedings under the Act.

By the end of the year, forty-one applications for increases of charges under the Act had been received, and ten cases had been decided; in the other cases, further investigations were required or the Department were awaiting the expiration of the legal period for objections.

POLLUTION OF RIVERS.

During the year eight applications have been received from Local Authorities for consent to take proceedings under the Rivers Pollution Prevention Acts in respect of alleged pollution from manufacturing refuse.

Local inquiries have been held in seven cases, and one awaits inquiry. Of the seven cases in which inquiry has been held orders consenting to proceedings have been issued in three cases. Remedial measures are promised in two cases. In another case pollution has ceased for the time being, and in the remaining case the decision has been postponed at the Local Authority's request, as the works at which the pollution arises are likely to be closed entirely.

The Minister of Agriculture and Fisheries appointed a small River Pollution Committee during the year for the purpose of assisting in the investigation of pollutions and of their effects on fish life. The Ministry of Health are represented on the Committee.

Probably the most serious cause of river pollution during the year, owing to the fact that it is a comparatively new and a growing source, has been the refuse discharged from dairies and cheese factories. The factory erected by the Ministry of Agriculture and Fisheries for the purpose of demonstrating the possibility of utilising the whey produced at the cheese factories has been in operation throughout the year, but at present this experiment has not developed far enough to justify the publication of results.

SEWERAGE AND SEWAGE DISPOSAL.

Activated Sludge Process.

A feature of the past year in regard to the sewage disposal question has been the increasing application of the activated sludge process of sewage purification.

The Department have kept in close touch with the experiments which have been carried out by the Local Authorities at, amongst other places, Sheffield, Manchester, Birmingham, Stoke-on-Trent and Reading.

At Sheffield an experimental unit designed to deal with one million gallons of sewage a day has been in operation for over twelve months with uniformly excellent results, the effluent being of good quality

and the costs low. The City Council have now decided, in view of the success of the experiment, to treat the whole of their sewage in this manner, and new works have already been put in hand.

It seems possible to draw the following conclusions from the experiments already carried out :

(a) The system is effective where the sewage to be dealt with is ordinary domestic sewage;

(b) The system is not so effective where there are exceptional qualities in the sewage; further experiment is required in such cases, though experience indicates that certain proportions of waste pickle from metal works and some trade refuse, such as brewery and dyeworks refuse, are without appreciable inhibitory effect;

(c) Of the two applications of the process (" agitated sludge " and air blowing"), both have resulted in the production of a good effluent. In the former system (which is in operation at Sheffield) the capital cost of installation is low, indicating the possibility of great savings, and the works are easily maintained. These advantages have not been so clearly demonstrated in the latter system.

The system of activated sludge has already been adopted at the following places :—

During the earlier part of the year, the need for stringent economy and for confining fresh expenditure to what was immediately necessary for public health, the coal dispute and trade depression, tended to discourage Local Authorities from undertaking works of sewerage and sewage disposal.

Later, however, the pressure of arrears accumulated during the war period, the need of sewers for new housing schemes, and, above all, especially in the latter part of the year, the urgent necessity for providing work for the large numbers of unemployed, resulted in many applications to the Department for sanction to loans for works of sewerage and sewage disposal.