Water quality management
As the nation's oldest multipurpose water reclamation project, SRP operates and maintains an
irrigation system that typically delivers more than 325 billion gallons of water to municipal,
industrial, agricultural and urban irrigation systems each year.
Water in the 131-mile-long canal system is a mix
of from the Salt and Verde rivers, the Central Arizona Project canal, groundwater pumped
from wells, and storm water and agricultural return flows. SRP takes a variety steps to
protect and monitor these water resources.
SRP has formed a partnerships with the Arizona Department of Environmental Quality to
address known pollution problems and work on projects such as groundwater well
remediation projects. Other partnerships for conserving water, monitoring and protecting
water quality have been developed with various cities in the metropolitan Phoenix area.
Environmental Compliance also routinely reviews proposed waste-water discharge permits
of non-SRP facilities to ensure that the water resources we manage are protected.
SRP monitors the water quality of both surface and groundwater supplies, and has undertaken
efforts to enhance the program. For example, nitrate probes have been installed along the Consolidated
Canal. Nitrate readings are transmitted back to a control center and adjustments are made to water
operations to manage nitrates levels in the canal.
SRP has also developed a steady-state, mass-balance water quality model to predict water quality
conditions in the canal under varying operating parameters.
One of SRP's most important water management programs is water quality monitoring. It provides
information about patterns and trends in SRP surface and groundwater quality and also about potential
pollution sources. SRP monitors the rivers within the watershed, as well as the canals and
groundwater wells within its water service area.
Water delivered by SRP is used for agricultural and urban irrigation, industrial processes, and
domestic needs. These different types of water users have different water quality needs. Although SRP
does not provide drinking water directly to the public, SRP performs voluntary monitoring of the raw
water delivered to municipal water treatment plants.
In response to a rapidly urbanizing community and heightened awareness of public health issues
related to drinking water, SRP has expanded its monitoring program to include testing of a greater
number of potential pollutants in SRP canals and wells. In addition to naturally occurring minerals,
SRP tests for volatile organic chemicals, heavy metals, and select pesticides.
Furthermore, SRP models flow conditions in the canals to help control nitrate levels in canal water
upstream of water treatment plants. Although nitrate concentrations in surface water are relatively
low, some groundwater wells contain relatively high concentrations and must therefore be diluted with
surface water to achieve acceptable levels in the canals.
Until recently, SRP collected samples from several sites on the Salt and Verde watersheds; however,
SRP now obtains this same data from the U.S. Geological Survey. SRP collects samples from various
sites on the canals monthly. Wells are sampled once per year, usually during the summer in conjunction
with pump testing activities. SRP has its own analytical laboratory, which is certified by the state
of Arizona.
SRP manages its power plants and other facilities to protect surface and groundwater resources. All
appropriate approvals and permits have been obtained for our facilities, such as those required under
the federal Clean Water Act and the Aquifer Protection Program.
SRP performs all monitoring and reporting required by various water quality protection laws,
regulations and permits. Permits or approvals are required for waste water discharges to surface
waters and municipal sewer systems, storm water discharges from construction sites and discharges that
have the potential to reach groundwater.
As a final check of our adherence to water quality laws and regulations, SRP regularly audits its
facilities and operations. Corrective actions are promptly taken to ensure compliance with applicable
requirements.
SRP strives to reduce the volume of chemicals stored, used and discharged at its facilities. As a
recent example, one of SRP's power plants eliminated the on-site storage of 22,000 gallons of sodium
hydroxide and reduced sulfuric acid storage from 20,000 to 1,000 gallons. These chemicals are used in
water treatment processes.
Another power plant reduced the on-site storage of sulfuric acid from 10,000 to less than 1,000
gallons and totally eliminated the on-site storage of 5,000 gallons of sodium hydroxide. These
reductions were achieved by replacing components of the water treatment system and utilizing
components that can be regenerated off-site.
Individuals can make a difference when it comes to preserving water quality. Among the steps you
can take are:
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Apply pesticides and fertilizers according to label directions. Do not over-apply.
The excess can run off in storm water and contaminate surface waters or migrate
to groundwater.
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Do not pour hazardous chemicals, such as antifreeze, oil, paints, stains, polishes or
solvents down a household drain, storm sewer, ditch or on the ground. Such actions
could contaminate surface waters or groundwater.
- Store lawn and garden chemicals in protected areas to prevent spills.