Ka ho?ohana ?ana i ka ?enehana membrane ultrafiltration i ka mālama wai inu Me ka ho?omau mau ?ana o ke ka?ina hana urbanization, ua ?oi aku ka nui o ka heluna o ke kūlanakauhale, ?oi aku ka nui o nā kumu waiwai o ke kūlanakauhale a me nā lako wai home.