Lead is generally found in water due to the corrosion of lead from solder and pipes found
in many older buildings. This corrosion is due, in most cases, to an acidic
environment (pH below 7). Lead in drinking water can also cause a
variety of adverse health effects. In babies and children, exposure to lead
in drinking water above the action level can result in delays in physical
and mental development, along with slight deficits in attention span and
learning abilities. In adults, it can cause increases in blood pressure.
Adults who drink this water over many years could develop kidney
problems or high blood pressure.
Lead is rarely found in source water, but enters tap water through corrosion of plumbing
materials. Homes built before 1986 are more likely to have lead pipes, fixtures and solder.
However, new homes are also at risk: even legally “lead-free” plumbing may contain up to 8
percent lead. The most common problem is with brass or chrome-plated brass faucets and
fixtures which can leach significant amounts of lead into the water, especially hot water.
EPA Standards:
When testing water for the presence of lead, HeraTech looks for the number of ppm, or
parts per million of lead in the water. The EPA has set the regulatory standard, or action level, at
0.015 ppm at first draw (the residual water in a fixture from overnight), or 0.010 ppm in a
standard well water sample.
Treatment: Cation Exchange Water Softener
If the problem is not due to the corrosion of pipes and solder in
the home, it is often best to use a Cation Exchange Water Softener at the
point of entry, or when the water enters the home. If the pipes are, in fact,
to corroding, it will often be necessary to install a point of use treatment
system as well. These are both only used if the pH of the water is below
7.
A water softener uses the principle of ion-exchange in this case,
cations to remove lead from raw water. The equipment contains a "bed"
of softening material known as 'resin' through which the untreated water
flows.
As water passes through the resin, the lead in the water attaches itself to this material. At
the same time, sodium in the resin is released into the water. This ion-exchange process occurs
literally billions of times during the softening process.
Regeneration:
Eventually, such a great quantity of lead collects on the resin that the unit can no longer
soften the water, and is now considered "exhausted." Regeneration, or recharging, is now
necessary. To recharge the resin, it must be rinsed with a rich brine solution. This washes out the
minerals and replaces them with sodium, so the resin is once again ready to remove minerals,
and 'soften' the 'hard' water.
During the recharging cycle, the unit is also backwashed. Reversing the normal flow of
water also serves to remove any turbidity and sediment which may have accumulated during the
softening process due to the filtering action of the ion exchange material. Backwashing also
loosens and fluffs up the bed of resin.
Care of Equipment
A softener should be kept recharged at all times. Failure to do so permits
contaminated water to flow into the pipes and water heater.
All water treatment equipment requires service. Whether removing a secondary standard
like iron or manganese or killing coli form bacteria, the importance of proper maintenance can't
be emphasized strongly enough.
When you receive the bill each month the cost of water is obvious if your source is a
municipal supplier. The fact your water comes from a private well does not exclude the need for
maintenance on a regular basis. While most home owners prefer a contracted service plan from
HeraTech, appointments on an as needed basis are also available. HeraTech has service programs that
include salt deliveries. Where this periodic testing is included in the initial installation cost
supplemental testing after the first year are the expense of the homeowner or can be included in
the service contracts.
Treatment: Block Carbon Filters
If the pH of the water is over 7, the lead will be in the form of
sediment. In this state, an ion exchanger is ineffective for purifying the
water. In these cases, block carbon filters are used to remove the lead
sediment.
Carbon filters are created by tightly packing carbon particles together to filter out
minerals, bacteria, and other harmful substances from your home’s water supply. A block
carbon filter is a very densely packed filter formed into a block with a binding medium.
There are numerous advantages to block carbon filters. They are able to filter out much
smaller particles than other filters. They are also not subject to bacterial growth inside of the
filter like other carbon filters.
Care of Equipment
All water treatment equipment requires service. Whether removing a secondary standard
like iron or manganese or killing coli form bacteria, the importance of proper maintenance can't
be emphasized strongly enough.
When you receive the bill each month the cost of water is obvious if your source is a
municipal supplier. The fact your water comes from a private well does not exclude the need for
maintenance on a regular basis. While most home owners prefer a contracted service plan from
HeraTech, appointments on an as needed basis are also available. We have service programs that
include salt deliveries. Where this periodic testing is included in the initial installation cost
supplemental testing after the first year are the expense of the homeowner or can be included in
the service contracts.
