Today, Students were given the opportunity to tour the Port Hueneme Water Agency’s Brackish Reclamation Demonstration Facility. The tour was led by the Lead Operator at the Facility and a VC Studen himself, Theo. This Facility is built for learning, and they welcome tours to the public, if interested.
The facility treats Brackish Water which is piped in from United Well Fields in El Rio, about 10 miles in land. The average processing rate is approximately 2500 GPM (Gallons Per Minute) which equals out to 3.6 Million GPD (Gallons Per Day)
The term “Brackish” water is another term for water with salts in it, which are at lower concentrations than seawater, but higher counts than freshwater.In the facility, there are 2 types of membrane filtrations used to treat the uses 2 types of membrane filtration, Reverse Osmosis (RO) and Nanofiltration (NF) side by side. In addition to these membrane filtration systems, the treatment plant also adds chemicals
On our tour, we learned that the deeper a well pumps from an aquifer, more minerals are present in the raw water, some of these being salts. It is becoming more present the deeper we pump from the United Water wells located in the El Rio well fields. United Water treats the raw brackish well water with sequestering agents to meet water quality regulations, and these sequestering agents aren’t always best for the membrane filters at this facility.
The reverse osmosis membranes strip the NaCl (salts) at the smallest molecular level, as well as other contaminants that tend to bond very strongly to water molecules. Chemical aids like sodium hypochlorite and aqua ammonia help the salt content to become more dense, so it can be extracted further with ease.
This isn’t seawater we are talking about mind you (which can be done but takes way more processes), but water with low salts present from the minerals deep in the aquifers that we are pulling up.
They told us that the brine that is the ‘leftovers’ of the salt is only about 20% of their total output. (80%=drinking water) which is really great. Seawater is about 40-60% as the salt content is MUCH higher than this groundwater….
The brine is then diluted to a safe level of salinity, and de-chlorinated by using Sodium Bisulfate. It is then released into the environment via the Salinity Management Pipeline (S.M.P.), which pumps the brine discharge 1 mile off shore of the Hueneme Coast.
Membrane Filtration at it’s finest – Nanofiltration (NF) on the left is first, then the water goes to the Reverse Osmosis (RO) Filters on the right. The RO membranes work at a smaller molecular level than the NF membranes, and together they make a beautiful team.
Nanofiltration Membranes look like THIS inside those white tubes. Water flows in through the top and the membranes (look like paper layers from the top) filter out many harmful pathogens, as well as initiate separation of the salts from the potable (drinking) water.