Meeting the 10ug/l Lead Standard Len Ellison Director HTC Management Services
Roman lead water pipes with taps about 500BC Lead is one of the first metals to be smelted and used, for Lead water pipes around 2,500 years Ago.
Gout was prevalent in Affluent Rome, it was thought to be the result of lead eating and drinking vessels.
The great disadvantage of lead is it poisonous Lead poisoning was among the first known and most widely studied work of an environmental hazard. Since Roman times, It was found that lead in dinking water can cause a variety of adverse health effects. Especially In children, exposure to lead in drinking water. decrease their IQ, and causes streaks of violence it also causes an increase in systolic blood pressure of adults In early 1900;s 45% of children who died under the age of 5, died from lead poisoning through drinking water.
2,500 years later 2,500 years later we are starting to get to grips with lead in water pipes. In 1998 the EU published the Drinking Water Directive which said the standard for lead in drinking water will change on December 31 st 2013 from ( 25 micrograms) 25ug/l to 10 ug/l and the point of compliance is at the customers tap. What has happened since then.
Phosphate dosing Phosphate dosing is the answer, so say a number of water companies, we have 99.0% of our homes below 25ug/L and 98% below10ug/l. There are 25m houses in the UK ( source BBC) 7m with lead water pipes (source DWI) How do they check, they have 99.0% compliance, Through random sampling. Most water companies do not know which houses have lead pipes, so the random sampling could be in an area which does not have homes with lead pipes. So is it going to be 99%.if they random sample in an area where all the house have lead water pipes?.
Compliance with the PCV for Lead from Water Company Compliance Monitoring 2001 to 2012 Year No Samples No of samples exceeding lead standard 25 (μg/l) 10 (μg/l) w 2002 20,682 273 1,023 2003 23,185 172 696 2004 25,158 123 692 2005 23,128 68 439 2006 26,450 90 568 2007 23,181 55 395 2008 13,153 30 143 2009 12,975 29 128 2010 12,667 22 127 2011 12,761 20 119 2012 12,475 23 108 In 2012 0.000499% of homes where random sampled for lead in water Source DWI PR14
Analysis of Thames Water Year No Samples No of samples exceeding lead standard 10 (μg/l) % 2008 1,806 27 1.5 2009 1,803 28 1.55 2010 1,798 31 1.72 2011 1,908 32 1.68 2012 1,898 26 1.37 (No problem) average 1.5% over 10 (μg/l) Source DWI PR14
WATER INDUSTRY ACT 1991: SECTION 19(1)(b) THE SECRETARY OF STATE FOR ENVIRONMENT, FOOD, AND RURAL AFFAIRS: 1) 1) is satisfied that Thames Water Utilities "the Company" is supplying water from the Distribution System in the Thames Region which may be at risk of exceeding the standard for Lead. This means that the Company is likely to contravene its duty in respect of supplying water which meets the Regulations under Section 68(1)(a) of the Water Industry Act 1991 and meets the requirement set in regulation 4(2)(c) of the Water Supply (Water Quality) Regulations 2000 Milo Purcell Deputy Chief Inspector Drinking Water Inspectorate DWI Ref No: TMS2934 1 September 2010 1) This section 19(1)(b) effected 28,000 homes in a small area of London little bit more than 1.5%. Thames started to open cut replace which they found too expensive, and asked for a quote for lining, They had to apply to the DWI to change from replacement to relining they still await an answer
Is Phosphate dosing the answer Most of the major consultancy companies in the water industry agree Phosphate dosing is not the long term answer. 1) It is a finite resources, 2) Cost continually rising, 3) water pipes in every house are dosed even if it does not have lead pipes 4) The Phosphate has to be removed at the wasted end. 5) Most European countries consider Phosphate dosing unacceptable on environmental grounds. 6) Phosphate dosing does not guarantee 100% compliance with the 10 μg/l lead standard So what are the alternatives to Phosphate Dosing?
Replacement 1) Open Cut 2) Moling 3) Pipe Pulling Rehabilitation 1) Lining 1) Replacement of lead pipes with open cut. Expensive and lead pipes are used as an Earth in the property, so if they are removed they have to be replaced at a cost of 150 per house. 2) Replacement with Moling, not always possible if you don t have a map of services of the ground, or you may hit hard ground, moling it becomes difficult, and can be dangerous. One operator died when the Mole head hit an electric cable. 3) Replacement with Pipe pullers, slow process which has high consumables costs with the steel rod used in the process 1) Rehabilitation lining the lead pipes. By far the cheapest and fastest option and most efficient production method with two men and one unit
Lead Pipe replacement/rehabilitation Costs Ave pipe length 7 m x 12mm dia, 2 men/1 Unit Earthing Set/Up Material Reinstatement Total/7m Ave/Units/Day Per/Ann 1) Open Cut 151 490 70 358 1069 1 240 2) Moling 151 238 99 102 590 2 480 3) Pipe Pulling 151 224 169 102 646 3 (3m/c) 720 4) Serline lining N/R 105 20 102 227 12 2880
Red lining is Epoxy, the Grey lining is a PU both linings have DWI Reg31(a) approval You can see from the photo the epoxy material is so brittle that it flakes off if the material is flexed, which happens to lead pipe in the ground
Serline System The Whirlwind Serline system is a process that utilises Whirlwind s forced air vortex system to both clean and dry the communication/service pipes and then apply a DWI approved PU coating to the clean and dry internal surface of the pipe, encapsulating them and preventing lead from permeating into the water, therefore reducing any lead contamination. Whirlwind s innovative technology is been able to provide a system to apply these resins, where size restricts the use of traditional methods. The Whirlwind forced air vortex technology allows injection of the mixed resin into a carefully controlled air flow, allowing the air to carry the product quickly down the pipe, and, at the appropriate point, depositing the fast curing resin to the dry wall of the pipe. It effectively uses the air stream as a pipe and, at the required position, creates turbulence to act as the application medium. Serline is the first small bore CIPP process to receive Drinking Water Inspectorate (DWI) Reg 31 4 (a) approval and successfully delivers significant improvements in water quality and environmental performance. Third party damages are minimised as the host pipe is already installed. The process can seal small holes and provide a leakage solution. Based on 2000 communication pipes being lined, the operation has proved to be around 80% more efficient than open cutting on busy main roads., resulting in a dramatic reduction of open excavations outside customer s houses which in turn reduces the volumes of traffic in built up areas being held up due to operations. When the lining unit is working to its full potential and excavations are kept to a minimum, the unit cost to refurbish the lead communication pipe is reduced even further
Who should be responsible for sampling drinking water The World Health Organisation (WHO) sees drinking water testing as an independent check on water providers to safeguard the health of water users. Page 64 4.3 Verification Verification provides a final check on the overall performance of the drinking-water supply chain and the safety of drinking-water being supplied to consumers. Verification should be undertaken by the surveillance agency; Transferring regulatory testing from water companies to local health organisations is one way to secure this goal