|The importance of Feed Water Quality & Seawater Wells
Feed Water Quality:
The feed water supply can be established from a variety of sources such as seawater
wells and open ocean intake all depending on geological conditions and / or local
regulations. To avoid possible unnecessary investments in pretreatment facilities, and
to extend the lifetime of the membranes, we always highly recommend our clients to
source the feed water from seawater wells where the seawater has been filtered
through the natural layers of sand and therefore normally is very clean.
Using seawater wells will not only avoid the complications arising from severe weather
conditions and related damage (compared to ocean intake), but also reduce the
capital investment and prolong the lifetime of the plant.
As far as the concentrate concern, we likewise recommend the drilling of a disposal
well where no pumps will be required as the reject brine will flow by gravity alone.
However, all depending on the circumstances, some clients also dispose (pump) the
brine direct back to the ocean by means of a pipeline system. HOH does not perform
any of the external requirements, but recommend consulting and using local expertise.
Feed Water Wells: (Seawater Wells / Beach Wells)
The following general notes should be observed in each case:
- Well site should be 50 to 500 m (150 to 1,500-ft) from possible source of pollution. Locate at elevated
point if possible to prevent flooding. Fence in well site.
- Well building should be fireproof, ventilated and in cold climates insulate thoroughly and provide heat.
Elevate above grade to provide drainage away from building.
- Pumping level is determined by continuous flow test at required well capacity, and the measurement of
the resulting draw-down below the static water table.
- The top of screen should be 20 m (60-ft) minimum below grade to avoid surface pollution, unless
unusually impervious earth, 3 m (9-ft) of compact clay, occurs at the surface, or well is far removed
from possible source of pollution.
HOH does not perform any of the external requirements, but recommend consulting and using local expertise.
However, the following links can be used as guidelines for the feed water supply.