Chapter 5 Conclusions and Recommendations
5.2 Recommendation for future study
1. Increase the number of sampling locations and include sampling sites with high lead exposure risk, such as residences with lead pipes and schools with old buildings. Moreover, new buildings could be set as the next target of inspection because new lead-bearing plumbing devices can release higher levels of lead in short term after installation.
2. Currently, the official sampling protocol in Taiwan for regular inspection is pre-flushing sampling, which does not comply with the latest global sampling protocol. The Department of Environment Protection should consider tap water sampling without prior flushing to identify the true lead exposure risk of residents.
3. Lead was detected in all samples in the field study, which implies that lead source exists in
water supply systems. It is speculated that brass plumbing devices were the main lead source. The government should strictly regulate the lead content of plumbing devices to less than 0.25%, which meets the newest definition of lead-free.
4. Perform lead testing for greater number of faucets because the lead leaching potential from each faucet can vary widely.
5. Apply sequential sampling method to identify the location of lead source in the plumbing system.
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Appendix A
S01
S02
S03
S0201 Breezeway
S0202 First floor,
beside classroom 102
S0101
Second floor, beside testing room
S0102 Third floor, beside resource classroom
S0103 Third floor, beside meeting room
S0104
Fourth floor, beside stair
S0301
Activity Center
S04
S05
S0405
Kitchen (sink) S0404
Kitchen
S0503
S0501 S0502
S0504 S0401
First floor,
beside children’s room
S0402 First floor, beside physical activity room
S0403
Second floor, beside aerobics classroom
S06
S07
S0602
Kitchen (Unfiltered water)
S0601
Kitchen (Filtered water)
S0701 Beside 1st grade, class 1
S0702 Beside 1st grade, class 2
S0703 Beside 20th grade, class 5
S08
S09
S0801
(Filtered water) S0802 Kitchen (Unfiltered water)
S0803 Basement first floor
S0901 Kitchen
(Unfiltered water)
S0902 Kitchen
(Unfiltered water)
S10
Residences Without Lead Pipe
S1001 Beside 3rd Grade, class 1
S1002 Beside special education class
W01 Kitchen (Unfiltered water)
W02 Kitchen
(Unfiltered water)
W03 Arcade
W04 Arcade
W05
Arcade W06
Arcade
Residences with Replacement of Lead Pipe
W07 Kitchen (Unfiltered water)
W08 Kitchen in kindergarten (Unfiltered water)
W09
Kitchen in restaurant (Unfiltered water)
W10 Kitchen
(Unfiltered water)
R02
Kitchen in restaurant R01
Kitchen
(Unfiltered water) R07 Arcade
Appendix B
R06 Taipei Water
Department
R08 Taipei Water
Department?
(PVC)
Residence (PVC)
R09 Residence
(PVC) Taipei Water
Department (Stainless Steel)
W01 Taipei Water
Department (Stainless Steel)
Residenc
W03
Taipei Water Department
Residenc e
W05 Taipei Water
Department Residence
(PVC)
W10
Taipei Water Department (Stainless Steel) Residence
(PVC)
W06 Residence
(PVC) Taipei Water
Department
Appendix C
Table 7. Water quality parameter data of school in first sampling campaign.
Water quality
Table 8. Water quality parameter data of residences with lead pipe replacement in first sampling campaign.
Table 9. Water quality parameter data of residences without lead pipe in first sampling campaign.
Table 10. Water quality parameter data of school in second sampling campaign.
bdata in brackets represents the turbidity value measured in first liter of sample
Table 11. Water quality parameter data of residences with lead pipe replacement in second
(NTU) pH Temperature (℃)
(NTU) pH Temperature (℃)
Table 13. Water quality parameter data of school in third sampling campaign.
bdata in brackets represents the turbidity value measured in first liter of sample
Water quality
Table 14. Water quality parameter data of residences with lead pipe replacement in third sampling campaign.
Table 15. Water quality parameter data of residences without lead pipe in third sampling campaign.
Water quality parameter
Water quality parameter
Appendix D
Following figures show the total/soluble copper, zinc, iron concentrations in the new faucet study.
Figure 13. The total and soluble copper concentration in tap water collected from five new faucets.
Total Copper Concentration (mg/L)
Days after installation
Soluble Copper Concentration (mg/L)
Days after installation
Total Copper Concentration (mg/L)
Days after installation
Soluble Copper Concentration (mg/L)
Days after installation
Total Copper Concentration (mg/L)
Days after installation
Soluble Copper Concentration (mg/L)
Days after installation
Soluble Copper Concentration (mg/L)
Days after installation
Total Copper Concentration (mg/L)
Days after installation
Soluble Copper Concentration (mg/L)
Days after installation
Total Copper Concentration (mg/L)
Days after installation
Lead-free Faucet 2
Legend
Figure 14. The total and soluble zinc concentration in tap water collected from five new faucets.
Soluble Zinc Concentration (mg/L)
Days after installation
Total Zinc Concentration (mg/L)
Days after installation
Soluble Zinc Concentration (mg/L)
Days after installation
Total Zinc Concentration (mg/L)
Days after installation
Soluble Zinc Concentration (mg/L)
Days after installation
Total Zinc Concentration (mg/L)
Days after installation
Soluble Zinc Concentration (mg/L)
Days after installation
Total Zinc Concentration (mg/L)
Days after installation
Soluble Zinc Concentration (mg/L)
Days after installation
Total Zinc Concentration (mg/L)
Days after installation
Lead-free Faucet 2
Legend
Figure 15. The total and soluble iron concentration in tap water collected from five new faucets.
Soluble Iron Concentration (mg/L)
Days after installation
Total Iron Concentration (mg/L)
Days after installation
Total Iron Concentration (mg/L)
Days after installation
Soluble Iron Concentration (mg/L)
Days after installation
Soluble Iron Concentration (mg/L)
Days after installation
Total Iron Concentration (mg/L)
Days after installation
Total Iron Concentration (mg/L)
Days after installation
Soluble Iron Concentration (mg/L)
Days after installation
Soluble Iron Concentration (mg/L)
Days after installation
Total Iron Concentration (mg/L)
Days after installation
Lead-free Faucet 2
Legend
Appendix E
Following figures show the raw data and size distribution of lead particles on 26/2/2020 in the new faucet study.
Figure 16
.
The raw data of lead particles on 26/2/2020 in the new faucet study.Figure 17
.
The size distribution of lead particles on 26/2/2020 in the new faucet study.Appendix F
Following figures show the mass concentration, mean size and number concentrations of copper, zinc, iron particles in the new faucet study.
Figure 18. The mass concentration, mean size and number concentration of copper particles in tap water collected from brass faucets.
Copper Particle Concentration (mg/L)
Days after installation
Copper Particle Concentration (mg/L)
Days after installation
Copper Particle Concentration (mg/L)
Days after installation
Copper Particle Mean Size (nm)
Days after installation
Copper Particle Mean Size (nm)
Days after installation
Copper Particle Mean Size (nm)
Days after installation
Copper Particle Number Concentration (particles/L)
Days after installation
Copper Particle Number Concentration (particles/L)
Days after installation
Copper Particle Number Concentration (particles/L)
Days after installation
Brass Faucet 3
Legend
Figure 19. The mass concentration, mean size and number concentration of copper particles in tap water collected from lead-free
Copper Particle Concentration (mg/L)
Days after installation
Copper Particle Concentration (mg/L)
Days after installation
Copper Particle Mean Size (nm)
Days after installation
Copper Particle Mean Size (nm)
Days after installation
Copper Particle Number Concentration (particles/L)
Days after installation
Copper Particle Number Concentration (particles/L)
Days after installation
Lead-free Faucet 2
Legend
Figure 20. The mass concentration, mean size and number concentration of zinc particles in tap water collected from brass faucets.
Zinc Particle Concentration (mg/L)
Days after installation
Zinc Particle Concentration (mg/L)
Days after installation
Zinc Particle Concentration (mg/L)
Days after installation
Zinc Particle Mean Size (nm)
Days after installation
Zinc Particle Mean Size (nm)
Days after installation
Zinc Particle Mean Size (nm)
Days after installation
Zinc Particle Number Concentration (particles/L)
Days after installation
Zinc Particle Number Concentration (particles/L)
Days after installation
Zinc Particle Number Concentration (particles/L)
Days after installation
Brass Faucet 3
Legend
Figure 21. The mass concentration, mean size and number concentration of zinc particles in tap water collected from lead-free faucets.
Zinc Particle Concentration (mg/L)
Days after installation
Zinc Particle Concentration (mg/L)
Days after installation
Zinc Particle Mean Size (nm)
Days after installation
Zinc Particle Mean Size (nm)
Days after installation
Zinc Particle Number Concentration (particles/L)
Days after installation
Zinc Particle Number Concentration (particles/L)
Days after installation
Lead-free Faucet 2
Legend
Figure 22. The mass concentration, mean size and number concentration of iron particles in tap water collected from brass faucets.
Iron Particle Concentration (mg/L)
Days after installation
Iron Particle Concentration (mg/L)
Days after installation
Iron Particle Concentration (mg/L)
Days after installation
Iron Particle Mean Size (nm)
Days after installation
Iron Particle Mean Size (nm)
Days after installation
Iron Particle Mean Size (nm)
Days after installation
Iron Particle Number Concentration (particles/L)
Days after installation
Iron Particle Number Concentration (particles/L)
Days after installation
Iron Particle Number Concentration (particles/L)
Days after installation
Brass Faucet 3
Legend
Figure 23. The mass concentration, mean size and number concentration of iron particles in tap water collected from lead-free faucets.
Iron Particle Concentration (mg/L)
Days after installation
Iron Particle Concentration (mg/L)
Days after installation
Iron Particle Mean Size (nm)
Days after installation
Iron Particle Mean Size (nm)
Days after installation
Iron Particle Number Concentration (particles/L)
Days after installation
Iron Particle Number Concentration (particles/L)
Days after installation
Lead-free Faucet 2
Legend