El Toro Water District Water Recycling Plant (WRP)
is located in South Orange County serving portions
of the cities of Laguna Hills, Mission Viejo, Aliso
Viejo, Lake Forest and all of the City of Laguna Woods.
Governed by a five member Board of Directors elected
at large, the District develops and implements policies
that meet the short and long range economic, water
resource and environmental goals of its customers
and the county.
The WRP is one of the oldest water recycling plants
in Orange County. Production and delivery of recycled
water for golf course irrigation has existed since
the WRP's inception in 1963, at which time the District
served a total population of about 125 on 4,750 acres
of land. Groundwater supplies were adequate to
meet the moderate domestic and agricultural
demand of the community at the time.
El Toro Water District's population has increased to 51,000.
The District has been able to meet its water demands from
a combination of water resources and technology that optimally
promote use of water conservation practices, water importation
and recycled water treatment and delivery.
||The District participates in ongoing
regional biosolids and recycled water treatment projects
through membership in the South Orange County Wastewater
Authority (SOCWA). The Regional Treatment Facilities
are located in the city of Laguna Niguel adjacent
to the regional park. The regional partnerships between
neighboring sister agencies and regulatory entities
provide an economic, environmentally sensitive and
efficient regional mechanism for effluent disposal,
biosolids recycling, and expanded and new recycled
water markets to serve South County customers within
and outside our service area boundary.
most recent improvement was a major reconstruction
and upgrade project of plant process components. The
project's goals were to meet anticipated regulatory
requirements, improve effluent and recycled water
quality, accommodate changes in wastewater characteristics
due to water conservation and position the District
to expand the use of recycled water locally and regionally.
The project achieved its objectives of compliance
with short and long term regulatory requirements,
while providing higher effluent and recycled water
aeration to reduce energy costs and improve oxygen transfer
scrubber technology to control odors.
to improve treatment control and reduce energy consumption.
water pumping capacity.
in power supply.
The wastewater treatment
process involves several steps. The incoming wastewater
enters the bar screens where large objects are removed that
could create problems for the downstream processes. It then
flows into the grit chamber where the heaviest materials
settle out and are hauled to a regulated landfill. Fine
screens then remove coarse organic materials for futher
Influent Pump Station
The equalization basins
provide temporary storage of wastewater when the incoming
flow exceeds the average daily flow. Wastewater is pumped
back into the flow stream during low flow periods of the
day. The equalized flow enhances the overall treatment process.
Air is continuously injected
into the wastewater at the aeration basins, which fosters
the growth of microorganisms that consume organic material
in the wastewater. The cultivated microorganisms eventually
settle out as solids in the secondary clarifiers. A
portion of the settled solid is returned to the aeration
basins and the excess is removed for disposal.
Water recycling consists of disinfecting and filtering the
secondary effluent. Sodium Hypochlorite is added to kill
harmful organisms. The secondary effluent is then passed
through filters to remove suspended solids. The disinfected
and filtered recycled water is delivered to restricted use
areas, such as the Leisure World Golf Course, Nursery and
Tennis Center, for irrigation purposes.
Solids produced during various stages of treatment are thickened
and trucked to the SOCWA facilities. Organic matter in the
solids is stablilized in the digesters. The digested solids
are dewatered and conveyed offsite for biosolids recycling.
Methane gas, a by product of digestion, is piped to the
Cogeneration Building to fuel generators that supplement
the plant's power needs.
The District is positioned for future tertiary treatment
which will provide expanded water recycling on a local and
regional basis. Tertiary treatment uses multimedia filtration
and chemical addition for further polishing and removal
of viruses and minute suspended solids. Tertiary treated
water is less restrictive and can be used more extensively
for commercial and public applications.