REUSE OF TREATED WASTEWATER FOR BENEFICIAL EFFLUENT MANAGEMENT IN ARID ENVIRONMENTS - ΤΕΕ
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REUSE OF TREATED WASTEWATER FOR BENEFICIAL EFFLUENT
MANAGEMENT IN ARID ENVIRONMENTS
Nikos Melitas, Stelios Pegadiotes, Theodore Papagiannis
County Sanitation Districts of Los Angeles County
1955 Workman Mill Road, Whittier, CA 90601, USA
KEYWORDS: wastewater, water, reuse, reclamation, effluent, management, Lancaster, California,
agricultural reuse, plant, effluent, activated sludge, oxidation ponds, management, arid, environment
ABSTRACT
County Sanitation District No.14 of Los Angeles County operates the Lancaster Water Reclamation
Plant in a way that promotes beneficial reuse of the treated effluent. Current beneficial uses include
agricultural irrigation of fodder crops, maintenance of an aquatic habitat, and municipal recreation. The
District is implementing a plan for accommodating a projected increase in population and the
accompanying increase in wastewater generation. The plan includes replacing the existing 16-MGD
(60.560 m3/d) oxidation pond facilities with a 26-MGD (98.410 m3/d) tertiary treatment facility, which
will include activated sludge, filtration, and disinfection. In addition to the existing reuse sites, future
sites will include an expanded agricultural operation and municipal projects.
EΠΑΝΑΧΡΗΣΙΜΟΠΟΙΗΣΗ ΩΣ ΩΦΕΛΙΜΗ ∆ΙΑΧΕΙΡΗΣΗ
ΕΠΕΞΕΡΓΑΣΜΕΝΩΝ ΑΠΟΒΛΗΤΩΝ ΣΕ ΑΝΥ∆ΡΑ ΠΕΡΙΒΑΛΛΟΝΤΑ
Νίκος Μελιττάς, Στέλιος Πηγαδιότης, Θοδωρής Παπάγιαννης
County Sanitation Districts of Los Angeles County
1955 Workman Mill Road, Whittier, CA 90601, USA
Ο Τοµέας Υγιεινής No.14 του δήµου Los Angeles διαχειρίζεται τή Μονάδα Επεξεργασίας Ύγρών
Αποβλήτων του Lancaster µε τρόπο που να προωθεί την επαναχρησιµοποίηση των επεξεργασµένων
λυµάτων. Οι τρέχουσες χρήσεις περιλαµβάνουν την άρδευση καλλιεργειών ζωοτροφών, τη διατήρηση
ενός υδρόβιου οικοσυστήµατος, και την αναψυχή των κατοίκων. Ο Τοµέας υλοποιεί ένα σχέδιο για να
µπορέσει να αντιµετωπίσει την προβλεπόµενη αύξηση των υδάτινων λυµάτων. Το σχέδιο
περιλαµβάνει την αντικατάσταση των υφιστάµενων αεριζόµενων λιµνών δευτεροβάθµιας
επεξεργασίας 60.560 m3/d µε εγκατάσταση τριτογενούς επεξεργασίας 98.410 m3/d, η οποία θα
περιλαµβάνει βιολογικούς αντιδραστήρες, φιλτράρισµα και απολύµανση. Οι µελλοντικές
εγκαταστάσεις θα επιτρέπουν ένα ευρύτερο φάσµα γεωργικών χρήσεων και δηµοτικών έργων
διάθεσης.
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 1
1. INTRODUCTION
In recent years, a growing population has resulted in increasing demand for freshwater supplies. As a
result, water has become a valuable commodity, and many communities are facing water management
challenges. Increasing wastewater production and more stringent environmental regulations have also
presented challenges to wastewater treatment and management of treated wastewater. Management of
treated effluent is especially challenging in areas lacking outlets to the ocean. Reuse, or reclamation,
of treated effluent provides a solution to effluent management. Moreover, it is a viable and economic
way to minimize impacts resulting from effluent discharge and other practices such as agricultural
irrigation. Further, reuse of treated effluent promotes conservation of limited groundwater resources,
provides beneficial uses of a valuable resource, and significantly reduces the costs associated with the
use of tap or ground water, groundwater pumping, and fertilizers.
County Sanitation Districts of Los Angeles County (Sanitation Districts) are a confederation of twenty-
five independent special Districts serving approximately 5.1 million people in Los Angeles County.
The Sanitation Districts' service area encompasses 78 cities and unincorporated territory within Los
Angeles County. The Sanitation Districts construct, operate, and maintain facilities to collect, treat,
recycle, and dispose of sewage and industrial wastes. The Sanitation Districts also provide for the
management of solid wastes, including disposal, transfer operations, and materials recovery. The
1400 miles of main trunk sewers and 11 wastewater treatment plants operated by the Sanitation
Districts' convey and treat approximately 510 million gallons per day (MGD) (1.930.350 m3/d) of
wastewater. The Sanitation Districts also operate three active sanitary landfills handling
approximately 19.500 tons per day. In addition to providing the aforementioned services, the
Sanitation Districts’ seek to maximize the beneficial reuse of treated effluent. Since 1970, when the
Sanitation Districts started their reclamation program, the amount of reused effluent has been
increasing. In 2003, reused effluent accounted for 45% of the total treated wastewater volume.
The Lancaster Water Reclamation Plant (LWRP), a treatment facility operated by County Sanitation
District No.14 of Los Angeles County (District), is located in the City of Lancaster approximately 73
miles (115 km) north of Los Angeles. The plant’s service area includes most of the City of Lancaster,
parts of the neighboring City of Palmdale and other unincorporated county area. LWRP is located in a
semiarid climate with temperatures ranging from 17oF (-8oC) to 106oF (41oC). Annual precipitation is
typically less than 10 inches (25,4 cm) and evapotranspiration is higher than 63 inches (160 cm) per
year. LWRP’s service area is located within the Lancaster groundwater sub-basin. Recharge of the
basin’s groundwater supply is primarily through infiltration of precipitation and runoff from the
surrounding mountains. Discharge occurs through pumping of groundwater [1] for domestic or
agricultural purposes. Increased pumping has resulted in a decrease in the groundwater deposit,
pumping depressions, and subsidence over large areas [1].
This paper presents current and future challenges faced by the District pertaining to wastewater
treatment and effluent management. Specifically, challenges faced by LWRP include accommodating
a rapidly increasing population and managing effluent in a desert environment lacking any sinks to the
ocean. The District plans to undertake these challenges in a cost-efficient way that promotes beneficial
use of the treated effluent and minimizes adverse environmental effects.
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 2
2. EXISTING FACILITIES AND EFFLUENT MANAGEMENT SITES
2.1 Lancaster Water Reclamation Plant
Since it was built in 1959, LWRP has undergone a series of expansions. Currently, the LWRP, shown
in Figures 1 and 2, has a design capacity of 16 MGD (60.560 m3/d) and treats an average of
approximately 13 MGD (49.200 m3/d). The LWRP provides primary treatment, through
sedimentation, and secondary treatment, through biological stabilization in oxidation ponds. Waste
stabilization is achieved in six oxidation ponds. Moreover, four additional ponds are used for storage.
Influent volume to the LWRP in 2003 was approximately 4818 million gallons (18,2 million m3), while
the total treated effluent volume for the year was approximately 4125 million gallons (15,6 million
m3). Undisinfected secondary effluent is being discharged to Nebeker Ranch for cultivation of fodder
crops. Disinfected secondary effluent is being discharged to Paiute Ponds, a marshland wildlife
habitat. Approximately 4% of the secondary effluent goes through tertiary treatment (secondary
sedimentation, filtration, and chlorination), and is discharged to Apollo Lakes Regional Count Park, a
recreational park. The LWRP operates under a permit issued by the California Regional Water Quality
Board – Lahontan Region. The permit specifies waste discharge requirements with which the plant has
to comply.
Rosamond Dry Lake
Location in California
Paiute Ponds
Lancaster Water Reclamation Plant
Oxidation Ponds Storage Ponds
Figure 1. Lancaster Water Reclamation Plant and Paiute Ponds Effluent Receiving Waters
2.2 Paiute Ponds
The Paiute Ponds cover an area of approximately 400 acres and are located within the property limits
of Edwards Air Force Base (EAFB). They consist of five main ponds and an extensive marshland
area, shown in Figures 1 and 3. The Paiute Ponds were created in 1961 by the construction of a dike
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 3that prevented the overflow of effluent to Rosamond Dry Lake. Since then, the Paiute Ponds have
evolved into an effluent dependent marsh-type habitat for more than 34 species. Part of the Paiute
Ponds is also used for duck hunting by EAFB personnel. The District has an agreement with EAFB
and the California Department of Fish and Game to provide Paiute Ponds with its effluent. In addition
to providing a perennial aquatic habitat in a region where such a habitat is uncommon, the Paiute
Ponds also provide a recreational and an environmental educational resource to the area. Potential
detriments associated with the presence of Paiute Ponds include the displacement of ephemeral habitat,
the release of toxic pollutants to the environment, and the potential of contamination of the regional
groundwater. Although approximately nine species (mostly terrestrial) were displaced, approximately
34 species (primarily avifauna) now reside in Paiute Ponds, resulting in a net increase of 25 species.
Other than the presence of ammonia in the effluent, which may at a certain concentration be toxic to
some species of fish in the ponds, no water quality concerns have been identified in the effluent. The
District is currently performing a study for developing ammonia specific criteria for discharge to
Paiute Ponds. Further, groundwater monitoring and an ongoing study have indicated that Paiute Ponds
are not contributing to any degradation of the regional groundwater aquifer. Groundwater monitoring
in the area has shown no water quality concerns. In addition, preliminary data obtained from an
ongoing hydrogeological study have indicated the presence of a substantial underground clay layer.
This clay layer isolates the regional groundwater aquifer from perched zones created from the
percolated water under the ponds. The quality of the effluent discharged to the Paiute Ponds is
regulated by the plant’s waste discharge requirements.
Figure 2. Lancaster Water Reclamation Plant, Lancaster, California
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 4The effluent not utilized by Nebeker Ranch and the Apollo Lakes is discharged to the Paiute Ponds.
Due to the increasing flow rate, the volume of effluent discharged to Paiute Ponds has exceeded the
evapotranspiration and hydraulic storage capacity of the Ponds. Consequently, the excess effluent
overflows to the adjacent Rosamond Dry Lake. EAFB considers the overflow to Rosamond Dry Lake
a nuisance because it is interfering with Base operations. Further, any nuisance caused by effluent
constitutes a violation of the LWRP waste discharge requirements. In order to minimize the period
during which overflows occur, the District is using its storage reservoirs, which have a total capacity of
500 million gallons (1,9 million m3), thereby limiting the overflows only to the six months between
November and April. It is estimated that approximately 1900 million gallons (7,2 million m3)
overflowed between November 2002 and April 2003. In order to comply with the LWRP waste
discharge requirements, the District must find alternative ways for managing this overflow volume.
Effluent Ove rflow
Rosamond Dry Lake
Piute Ponds
Figure 3. Paiute Ponds, Lancaster Water Reclamation Plant Effluent Receiving Waters
2.3 Nebeker Ranch
During 2003, approximately 1350 million gallons (5.1 m3), comprising approximately 30% of the total
LWRP effluent were used for irrigation of a fodder crop at Nebeker Ranch. Nebeker Ranch is a
privately owned farm located approximately four miles (6 km) northwest of LWRP. Figure 4 shows
Nebeker Ranch during harvest. Water is pumped to the Ranch to irrigate approximately 620 acres
(251 hectares) of alfalfa. The effluent is surface spread across approximately 40-foot-wide rows in
lengths of approximately a quarter mile [2]. The water use is determined by Nebeker Ranch according
to evapotranspiration rates for alfalfa adjusted by a factor that accounts for the efficiency of the
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 5irrigation method. Irrigation inefficiencies arise from a non-uniform distribution of water on the field.
Typically, the efficiency of the Nebeker Ranch irrigation method can reach approximately 80% [3].
Consequently, the volume of water required for proper irrigation is higher than the theoretical
evapotranspiration rate. Reuse of the LWRP effluent for agricultural purposes is beneficial to the
District, Nebeker Ranch, and the surrounding community. In the absence of Nebeker Ranch as an
effluent sink, the District would be forced to discharge the effluent to Paiute Ponds, thereby increasing
the overflows, or find alternative effluent management sites. Further, according to State regulations
(California Code of Regulations and the Department of Health Services) secondary undisinfected
effluent can be used for irrigation of fodder crops. Alternatives to irrigation of fodder crops would
likely require more expensive advanced treatment techniques. Benefits to Nebeker Ranch include
avoiding the cost of pumping groundwater and the cost associated with application of fertilizers.
Effluent from the plant contains all nutrients required for plant growth thus eliminating the need for
fertilizers. Finally, use of effluent for irrigation is beneficial to the community as it contributes to the
conservation of valuable groundwater supplies.
Nebeker Ranch
Apollo Lakes
Paiute Ponds
Figure 4. Lancaster Water Reclamation Plant Effluent Reuse Sites
2.4 Apollo Lakes Regional County Park
Apollo Lakes Regional County Park, shown in Figure 4, is located approximately six miles (10 km)
southwest of the LWRP. The park consists of a grassy area and three interconnected lakes with a total
area of 26 acres (10,5 hectares). The park is operated by the County of Los Angeles, Department of
Parks and Recreation, and is used for public recreation, boating, and fishing. Tertiary effluent from the
LWRP is conveyed to the park for maintenance of the lakes, landscape irrigation, dust control, and fire
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 6protection of a small municipal airport. The diversion of effluent to the park area benefits both the
District and the Apollo Park. The water demand by Apollo Park reduces the amount of effluent that
otherwise would have been discharged to Paiute Ponds. Moreover, the park is able to reduce its
operating cost by using effluent instead of freshwater for park maintenance. Finally, because it is
located in a desert environment lacking any surface waters, the park provides a valuable recreational
resource to the public.
3. PLANNING OBJECTIVES
Current and future challenges faced by the District in regards to the operation of the LWRP and the
management of its effluent are: 1) accommodating the projected wastewater flow rates, 2) eliminating
the overflows to Rosamond Dry Lake and managing effluent remaining after the overflows have
ceased, 3) maintaining the Paiute Ponds habitat, and 4) providing effluent of a quality suitable for
beneficial uses besides irrigation of forage crops.
3.1 Accommodation of Projected Wastewater Flows
According to the most recent population forecast [4] for Antelope Valley, the projected population
within the District’s service area for the year 2020 is estimated to approximately 250.000. This
population and the associated industrial activities as well as contracted flow rates are expected to
generate approximately 26 MGD (98.410 m3/d) of wastewater. The LWRP’s current capacity of 16
MGD (60.560 m3) is expected to be reached by 2008. As a result, the LWRP must be expanded to
accommodate the projected wastewater flows.
3.2 Elimination of Flows to Rosamond Dry Lake
As discussed, the District has to eliminate overflows to Rosamond Dry Lake because they constitute a
violation of the LWRP waste discharge requirements. Therefore, the District needs to limit the amount
of effluent that may be discharged to Paiute Ponds to the amount lost from the Paiute Pond system. As
a result, the District will need to manage approximately 1900 MGD (7.2 million m3) that will remain
after overflows to the Rosamond Dry Lake have ceased.
3.3 Maintenance of Paiute Ponds Habitat
Without the effluent from the LWRP, Paiute Ponds would cease to exist. As a result, a three-party
agreement with EAFB and the California Department of Fish and Game, requires the District to
maintain a minimum of 200 wetted acres (81 hectares) of habitat at Paiute Ponds. The District is
planning to maintain all of Paiute Ponds at their current area of approximately 400 acres (162
hectares). Since no overflows are permitted, the District can only discharge effluent equal to the losses
from the Paiute Pond system. These losses include evapotranspiration, percolation, and seepage. To
accomplish that, the District is developing a hydrological model, which will determine a water balance
for the system and calculate the loss components. Another challenge involved is managing Paiute
Ponds to maintain a healthy habitat after overflows have ceased. For example, when overflows occur,
the system is flushed and high levels of salts and other constituents that may be detrimental to the
habitat are not permitted to accumulate. Without overflows, evapotranspiration may concentrate
constituents to potentially toxic levels. For that purpose, the District is constructing a water quality
model to assess the current water quality in the ponds and determine the effects to water quality after
the overflows cease. If it is determined that there will be an adverse effect to the system, the District,
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 7EAFB, and the Department of Fish and Game will need to develop an alternative effluent management
strategy.
3.4 Producing Effluent Water Quality Suitable for Additional Beneficial Uses
Presently, the water quality of the effluent meets all environmental regulations for its current beneficial
uses; however, the District has to extend its reuse alternatives. Therefore it must be able to provide
effluent suitable for additional beneficial uses, which may require more advanced treatment. For
example, the City of Lancaster has decided to implement a project that will use up to 1.5 MGD (5.680
m3/d) of effluent for landscape irrigation and industrial purposes. Environmental regulations require
that recycled water used for these purposes undergo tertiary treatment. Consequently, secondary
effluent from the LWRP does not meet the water quality required for these beneficial uses. The
District, however, is committed to providing recycled water to the City of Lancaster and other
customers to satisfy the current and future demands. As a result, the LWRP’s tertiary treatment
capacity must be expanded.
4. FACILITIES PLAN FOR YEAR 2020
In order to meet all of the aforementioned objectives and the 2020 wastewater projections, the District
has prepared and started to implement a facilities plan for the LWRP [5]. Initially, the District
evaluated a range of wastewater treatment and effluent management alternatives. As a first screening
process, the treatment and effluent management alternatives were evaluated individually. This process
identified a recommended treatment alternative and two effluent management alternatives that were
combined into a set of final project alternatives. A recommended project was selected following a
second screening process of evaluating the final alternatives.
4.1 Selection of Wastewater Treatment Process
The wastewater treatment capacity of the LWRP must be expanded from 16 MGD (60.560 m3/d) to 26
MGD (98.410 m3/d), the 2020 projection. The expansion will involve construction of additional
primary, secondary, and tertiary treatment facilities. Tertiary treatment will involve filtration and
disinfection. Secondary treatment alternatives included oxidation ponds, conventional activated sludge
(CAS), oxidation ditches, and membrane bioreactors. Tertiary treatment will follow these
alternatives. The treatment alternatives were evaluated for cost effectiveness, environmental impact,
operational considerations, and effluent quality. Based on these criteria, CAS/Tertiary treatment was
selected.
4.2 Selection of Effluent Management Alternatives
While maintaining the existing reuse sites of Paiute Ponds, Nebeker Ranch, and Apollo Lakes, and the
1.5-MGD proposed municipal project, the District considered the following effluent management
alternatives: discharge to the Los Angeles Aqueduct, groundwater recharge, discharge to evaporation
ponds, agricultural reuse combined with storage reservoirs, agricultural reuse combined with land
application, municipal reuse combined with storage reservoirs, discharge to constructed wetlands, and
seasonal discharge to Rosamond Dry Lake. The effluent management alternatives were evaluated for
compliance with the set objectives, feasibility, cost effectiveness, and environmental impact. Based on
these criteria, two potential options were selected: Agricultural Reuse/Storage Reservoirs, and
Agricultural Reuse/Land Application.
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 84.3 Selection of Final Project
The recommended wastewater treatment alternative, CAS/tertiary treatment, was combined with the
two recommended effluent management alternatives to create four final options.
4.3.1 Alternative 1 (16 MGD CAS/Tertiary Treatment, 10 MGD Oxidation Ponds Treatment,
Agricultural Reuse/Storage Reservoirs)
The first alternative comprised the expansion of the current 16-MGD facility by construction of a 10-
MGD CAS/tertiary treatment facility. This alternative included the acquisition of approximately 4170
acres of land for development of agricultural operations. The agricultural area was determined based
on the area required to apply all effluent remaining from the other uses at agronomic rates. Providing
water at agronomic rates ensured that the crop would receive all the necessary water for a healthy
growth, while minimizing percolation to the groundwater. Agronomic rates were determined based on
the annual average crop demand (evapotranspiration) multiplied by a factor of 1.2. This factor
accounted for losses resulting from factors such as the distribution efficiency of the irrigation system,
soil infiltration rates, etc. The alternative contemplated the use of a center pivot irrigation system,
which is the most efficient method in terms of distribution efficiency and operational flexibility. This
alternative also included the acquisition of approximately 1100 acres for construction of storage
reservoirs with a total capacity of approximately 3380 million gallons. During the winter, when
recycled water demand is low, excess effluent would be held in the reservoirs. During the summer
months, stored effluent would supplement the newly produced effluent to meet the high water demand.
4.3.2 Alternative 2 (26 MGD CAS/Tertiary, Agricultural Reuse/Storage Reservoirs)
This alternative was similar to Alternative 1, except that it included the construction of a 26-MGD
CAS/tertiary treatment facility to replace the existing facility. Effluent management was the same as
Alternative 1, including agricultural reuse combined with the use of storage reservoirs. Under this
alternative, acquisition of approximately 4650 acres would be necessary for agricultural reuse.
Approximately 750 acres would be needed for the construction of storage reservoirs with a total
capacity of 2300 million gallons.
4.3.3 Alternative 3 (16 MGD CAS/Tertiary, 10 MGD Oxidation Ponds, Agricultural Reuse/Land
Application)
This alternative included the expansion of the current 16-MGD facility by construction of a 10-MGD
CAS/tertiary treatment facility. Under this alternative, land application of effluent would be used in
lieu of storage reservoirs. Land application would require that water be applied to crops in excess of
agronomic rates. Approximately 13900 acres of land would be required under this alternative. This
area is larger than that required by Alternatives 1 and 2 because a winter, instead of an annual, average
crop demand was used in the calculation. As a result, during some winter months, water would be
applied in excess of agronomic rates. However, in the summer, there would be insufficient water for
cultivation of the whole area. Therefore, the District would have to supplement effluent with
groundwater or maintain some land as fallow.
4.3.4 Alternative 4 (26 MGD CAS/Tertiary, Agricultural Reuse/Land Application)
This alternative included the construction of a 26-MGD CAS/tertiary treatment facility to replace the
existing facility. Effluent would be managed similarly to Alternative 3. Approximately 13900 acres
would be required under this alternative.
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 94.3.5 Recommended Project
The four final alternatives were evaluated based on environmental impact, operational considerations,
optimization of effluent reuse, public perception, and cost. Alternative 2 was proposed as the
recommended project due to its cost effectiveness. Alternative 2 ranked first with respect to
environmental impact, reuse optimization, and public perception. Alternative 2 ranked second when
evaluated based on capital and operation and maintenance costs.
5.0 CONCLUSIONS
County Sanitation District No.14 of Los Angeles County operates the Lancaster Water Reclamation
Plant in a way that promotes a beneficial reuse of treated effluent. Current beneficial uses include
agricultural irrigation of fodder crops, maintenance of an aquatic habitat, and municipal recreation.
Recent projections predict a rapid increase in the population served by the Lancaster Water
Reclamation Plant. This increase in population will result in a corresponding increase in wastewater
generation. The amount of generated wastewater is expected to exceed the plant’s current capacity of
16 MGD (60.560 m3/d) by 2008, and reach 26 MGD (98.410 m3/d) by 2020. In order to accommodate
the projected flows and to comply with the plant’s waste discharge requirements, the District has
developed and started the implementation of the 2020 Facilities Plan. According to the Plan, the
existing 16-MGD (60.560 m3/d) oxidation pond treatment facility will be replaced by a 26-MGD
(98.410 m3/d) facility providing secondary activated sludge treatment and tertiary treatment through
filtration and disinfection. In addition to the existing reuse sites, future reuse sites will include an
expanded agricultural operation and municipal projects.
REFERENCES
1. U.S Geological Survey (2003) ‘Simulation of Groundwater Flow and Land Subsidence, Antelope
Valley Ground-Water Basin, California.’ Water Resources Investigations Report, 98, 4022.
2. Nebeker B. E. (1994) ‘High Technology in Alfalfa Farming Today’ The Journal of the Antelope
Valley Heritage Foundation, 3, 16-18.
3. Lambert D. B. and Nebeker B. E. ‘Compatibility of Agricultural and Suburban Interests:
Agricultural Reuse of Reclaimed Water in the Antelope Valley, California’, Proc. Conf. Water
Reuse, San Diego, California, 1996.
4. South California Association of Governments ‘Regional Transportation Plan’, 2001.
5. County Sanitation Districts of Los Angeles County (2004) ‘Lancaster Water Reclamation Plant
2020 Facilities Plan’, CSD.
HELECO '05, ΤΕΕ, Αθήνα, 3-6 Φεβρουαρίου 2005 10You can also read
