§ Mr. Teddy Taylorasked the Secretary of State for the Environment (1) if he will now take steps to collect, centrally, statistics showing the number of occasions on which water authorities advise local medical officers of health that the nitrate level in public water supplies has exceeded 50 mg per litre; and if he will make a statement.
(2) what percentage increase in nitrate levels has occurred in groundwater and other sites monitored by his standing technical advisory committee over the past 20 years; and if he will make a statement.
§ Mr. Giles ShawSurveys show that in the last 20 years there have been increases of the nitrate concentration in most ground and surface waters. But in only about 150 sources, out of some 3,500, does the nitrate level of occasion exceed 50 mg/litre. I am now arranging that all water authorities notify me routinely of the occasions on which the nitrate concentration in water supplies in their areas exceeds 50 mg/litre and whether the area health authorities and district councils have been informed.
Clearly, in some areas, the general trend of nitrate concentration in water sources is rising and some supplies 272W are being affected. I am personally contacting the most affected water authorities to determine a suitable programme for dealing with the problems that may arise.
§ Mr. Teddy Taylorasked the Secretary of State for the Environment on how many occasions the Anglian water authority and the water companies operating within the authority's area were obliged to advise medical officers of health that nitrate levels had exceeded 50 mg/litre in 1982.
§ Mr. Giles ShawDuring 1982 the statutory water undertakers in the Anglian water authority area advised area health authorities and district councils on some 80 occasions regarding nitrate concentration in water supplies exceeding 50 mg/litre.
§ Mr. Teddy Taylorasked the Secretary of State for the Environment on how many occasions the nitrate levels in the water in the river Stour exceeded the 50 mg/litre level in the most recent three year period for which figures are available.
§ Mr. Giles ShawRaw water from the river Stour, sampled at the Langham abstraction point, had a nitrate concentration exceeding 50 mg/litre for a significant period in each of 1980, 1981 and 1982. A few water supplies using this source exceeded 50 mg/litre during 1980 and 1981 but, following an improvement in the blending scheme, none exceeded this level in 1982.