asked Her Majesty’s Government:

What proportion of passenger trains in the United Kingdom continue to discharge raw sewage on the tracks; and when they expect the practice to end.

My Lords, the Government’s investment in new rolling stock has seen the withdrawal of hundreds of trains that did not have retention-tank toilets. That leaves about 13 per cent of the fleet with non-retention tank toilets, all of which we expect to be withdrawn or converted by 2020.

My Lords, I have been asking Questions about this for the past four years. The Government’s gradualist approach is certainly very gradual. My own route home to Cornwall and the high-speed service on the east-coast route between Edinburgh and London—two of the longest routes in the country—are covering trackside workers and nearby properties with a fine mist of effluent. Do Her Majesty’s Government think it acceptable for railway maintenance work to be carried out in an environment that is contaminated by untreated human waste?

My Lords, progress is such that, in the past six years, we have seen the figures for trains go down from 36 to 13 per cent; so we are making progress. The problem is that the trains have a long life of 30 to 40 years. Some trains would be extremely expensive to convert, and we cannot replace them immediately. Let me reassure the noble Baroness that the trade unions for trackside workers, which have been aware of this issue for very many decades, do not regard it as a health issue for workers on the track.

My Lords, is the Minister aware that some of the best tomatoes I have ever seen grow spontaneously at sewage farms? Are they safe to eat?

My Lords, none of the train-operating companies with which we have been in contact on this question replied to us on the efficacy of growing tomatoes.

My Lords, even caravans have sealed units, so can the Minister say, with 2012 coming nearer and nearer, how overseas visitors will react when they are told that they cannot use the lavatory if the train is in a station?

My Lords, visitors from Europe will discover that there are fewer trains in this category in the United Kingdom than in almost any rail system in Europe. We are ahead of other rail systems in making progress in this respect.

My Lords, if this Question has been asked for four years, are the Government really treating it seriously or are they simply going through the motions?

My Lords, I knew I would have to tread carefully with this Question. The Government and previous Administrations have been aware of this issue for decades. The problem is quite straightforward: all new train units with toilets that come on stock have the correct processes in place. We are dealing only with trains that it will take time to phase out, because of their durability.

My Lords, in awarding franchises to the rail-operating companies, has not discharging raw sewage been included as a criterion in any of the franchises where the train operator would be asked to convert the toilets by attaching containers to the toilet cubicles?

My Lords, there is clear and very good news on that front. The rail industry as a whole in 1996 adopted a code of practice that all new rolling stock fitted with a toilet would have to be fitted with a retention tank into which the toilet would discharge.