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TREATMENT PERFORMANCE - CONTINUED
(B) Limestone Contactor Performance in Several New Hampshire
Water Systems
There are several water systems in New Hampshire that use limestone
contactors for corrosion control (Lucey, 2003). These systems
include community water systems and non-transient community water
systems (Thayer, 2001). Most of these water systems obtained their
raw water sources from bedrock wells. Others obtained their raw
water sources from either gravel well or surface water (Thayer,
2001). 
5 shows the summary of treatment performance of the limestone
contactors in New Hampshire.
(C) Limestone Contactor Performance in Bredasdorp, South
Africa
In Bredasdorp, problems of “blue” and “red”
water were common prior to limestone stabilization in 1996 (Daniels
et al., 2002). Blue and red water are caused by high level of
iron and copper.
6 shows the effectiveness of limestone contactor by comparing
the water quality before (in 1996) and after stabilization (in
2001). The treated water quality was monitored at various sampling
points within the Bredasdorp drinking water distribution network.
After limestone stabilization, the treated water characteristics
within the network were improved. The Calcium Carbonate Dissolution
Potentials (CCDP) were low and the pH values were generally greater
than 8.3 (Daniels et al., 2002).
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