Recycled Water & The Water Cycle
The Water Cycle. We learn it in elementary school, but what does the water cycle mean to us today? As our sources of water (rainfall, groundwater, seawater, recycled water, etc.) evolve, so does our sense of how water is connected on our planet. Mother Nature has been reusing water on Earth for a very long time. And though H2O is a simple molecule made up of three atoms, two hydrogens and one oxygen, water is surprisingly difficult to create or tear apart. This causes water to hold its structure as it is naturally recycled again and again.
How does water cycle on Earth? We had it mostly right in elementary school except for the human additions. Half of the process happens up in the sky with rain and clouds, but the other half happens on the surface, underground, and in treatment plants. Water is collected in lakes, rivers, streams, reservoirs, groundwater lakes and rivers (aquifers), and the sea. From there, it either continues on in the water cycle, it is used directly by plants and animals, or it is treated for human use. After plants and animals use water, it is released back into the atmosphere, the ground, or bodies of water. After humans use water, it is treated to remove pollutants before rejoining the natural water cycle.
With the advancement of water treatment technologies, we have found proven ways to treat water to higher standards, making it safe for more uses. Take recycled water for example. With the advanced technology we have today, we can produce purified water that is safe to put directly back into our drinking water supplies, either in the ground or in bodies of water. This technology enables us to do what nature does to clean water, but on a human time scale. We can recycle and use the water for everyday potable uses today and tomorrow, complementing Mother Nature and providing much needed drinking water for the community.
Groundwater is water found underground in the cracks and spaces in soil, sand and rock. Groundwater is stored in these geologic formations, known as aquifers, and can move through the spaces in the soil or rock, similar to underground lakes and rivers. Groundwater is naturally replenished, or recharged, by precipitation that seeps into the cracks and reaches the aquifer.
Just as with surface water, when groundwater is used faster than it is replenished, such as in times of drought, water levels drop and the stores become depleted. In a coastal basin such as the Santa Maria Groundwater Basin, if the groundwater level sinks too far, it is possible for seawater to enter the aquifer and mix with the potable groundwater supplies. This is not safe for our cities and towns, our drinking water supplies, or the environment. In order to combat this potential problem and augment the naturally slow process of groundwater recharge by infiltration, the Central Coast Blue project will create a new source of clean, purified water to put back into the ground. This will create a safe and sustainable supplemental water supply and protect the Santa Maria Groundwater Basin from seawater intrusion.
Groundwater recharge achieved by injecting purified water is also known as Indirect Potable Reuse (IPR). IPR is a type of reuse where water is blended with other environmental systems, such as a river, reservoir, or groundwater basin before the water is reused. Regulations for this type of IPR were adopted by the California State Water Resources Control Board in 2014. The California Water Board strictly regulates all types of reuse projects and thoroughly investigates projects and processes for viability and safety before regulating them.
This Library contains studies and technical reports related to the planning and design of the Central Coast Blue project.