A fresh, non-seawater surface water supply may not require desalination treatment if the salinity is already
within secondary US EPA water quality guidelines. However, in an increasing number of utilities, brackish
water desalination is utilized for targeted reduction of undesirable parameters (and in some cases, even
removal of TDS to for existing distribution system compatibility). Fresh surface water – just like seawater –
is associated with containing viruses and pathogens. Therefore, microfiltration (MF) or ultrafiltration (UF)
are membrane-based alternatives to conventional granular media or other similar treatment processes to
meet US EPA drinking water quality standards if desalination is not needed. Because of this, MF and UF
are frequently utilized as low-pressure membrane pretreatment alternatives for removal of non-ionic
species such as suspended matter or viruses and pathogens.
Table 1 (below) contains the range of typical pressures associated