The solution to the lead issue in drinking water would optimally be replacement of all lead piping.
However, there are certain issues:
- The ownernership of the lead piping is between the supplier and the property owner, leading to possible legal aspects.
- The replacement costs are very high. Approximately 8-10 billion sterling pounds to replace all lead piping in the UK
- The density of properties with lead piping can be up to 75% in many cities. The replacment program would create much disruption to road users and property owners
- When the lead in water is not visible, tasted, odorless, it is not perceived as a problem. Property owners are then reluctant to take expensive actions.
Corrective Treatment
Another solution is corrective treatment as opposed to the replacement of lead pipes throughout the UK. It has allowed for the UK to achieve the new European standards for lead in drinking water. Approximaely 95% of the UK water supplies are now dosed with ortho phosphate to achieve the European standards (interim 25 ug/l and 10 ug/l in 2013 ) The Government will assess the extent of the compliance in the next few years. It will then be determined if a strategic program of lead pipe replacement would be necessary and if so, to what extent to meet 10ug/l compliance standard
Ortho Phosphate
Controversy exists with the usage of ortho phosphates. Other European countries consider the ortho phosophates unacceptable due to the chemical creating environmental stress. The eutrophication of water bodies and possible prolific growth of algae. The amount used is 1 mg/l P. For perspective, the sewage derived from water use has a concentration of approximately 10 mg/l P. (It is derived mostly from human waste, some detergents) And the European legislation requires phosphate removal down to only 1 or 2 mg/l P.
Whatever the decision for long term correction, it must be balanced with public health consequences along with enviornmental impact.