The overall problem of chlorides in our water is a regional one, caused by a number of factors that are often outside the control of local governments. Most of the chloride in our rivers and aquifers comes from untreated wastewater effluent. By the time wastewater spills from one underground aquifer to another, or drains from a river into a basin (from which most wells draw water), the chloride levels are at too high a concentration to meet State and Federal water quality standards. Chlorides have been increasing in river watersheds for decades, and have now reached levels in the aquifers that are beginning to interfere with farming and municipal use. Crops such as avocados and strawberries are very sensitive to chlorides particularly in the subsoil around their main root zone, where the impacts of chlorides restrict the uptake of nutrients such as nitrates and sulphates ultimately hindering the plants abilities to flourish. Chlorides in the soil are taken up by plants very rapidly and in considerable amounts where it accumulates into the vegetative parts and exhibits a strong osmotic effect. If chloride levels in the irrigation water rise beyond a specific range it can cause plants and trees to look “burned”, or substantially decrease crop yields, which has a direct financial impact on local economies.
To address this challenging chloride problem, OWS has designed a hybrid Ecological / Reverse Osmosis system that can operate at 1/3 to 1/2 the costs of a full pump and treat system. Ecological lagoons are employed in this hybrid approach, which house several bio-diverse low energy processes for water quality improvement and chloride reduction.
This twofold OWS approach of wastewater upgrade and chloride reduction on the same site yields treated effluent that is both suitable for irrigation, and in compliance with State and Federal water quality standards. Additionally, our approach has the potential to fundamentally shift municipal relationships with Regional Water Quality Control Boards - from compliance to collaboration.