WASTEWATER RECYCLING PLANT REPORT

WASTEWATER RECYCLING PLANT REPORT

WASTEWATER RECYCLING PLANT REPORT

The purpose of this report is to promote wastewater recycling by designing a well-organized wastewater recycling plant. This report will address the value of recycled wastewater, the operational functions that will determine the facility design, and strategies for the mitigation of associated risks. Additionally, the preferred method for recycling water will be discussed, along with engineering and equipment costs, and water quality and regulation considerations.

The report is written from the perspective of a member who is part of an advocate force promoting wastewater recycling. The selected local city council in this exercise is El Dorado Hills (EDH), California which currently supports thousands of homes with recycled water. Although there are currently two treatment plants in EDH, more are needed. Additional facilities can mitigate the impact of the present California drought, by providing much needed drinking water for residents, livestock, and also support community projects such as landscaping (Hudson Sangree, 2014). Given the nominal population size of EDH, one proposal will be to leverage the plant for overflow Wastewater from nearby cities such as Folsom, Cameron Park, Orangevale, Fair Oaks, and Citrus Heights.

From a macro-perspective California is an ideal location due to the $200 million dollars allocated for various water recycling projects. This funding is part of the drought relief measures that have also decreased interest rates on $800 million in water project loans. California Governor Brown recently signed new legislation to determine the feasibility of uniform standards for wastewater recycling. With a September 2016 deadline, the development of additional wastewater recycling plants could also provide a higher volume of empirical data useful for such a feasibility study. Especially if the El Dorado city council agrees to leverage the overflow of surrounding communities. Depending on the willingness of other cities there could be a usage tax applied, creating additional revenue for El Dorado and offsetting the construction costs (Hudson Sangree, 2014).

Purpose of the Proposed Wastewater Recycling Plant

In 2009 the Department of Water Resources and the State Water Resource Control Board came together to conduct a survey. The purpose of the survey was to determine the volume of wastewater currently being recycled in California. One notable statistic is that more than 669,000 acre-feet of water is currently being recycled in California. This is an increase of 144,000 acre-feet or approximately 22% of recycled water since 2001. One of the first points made to the El Dorado city council will be the importance of increasing the number of wastewater recycling plants, in order to accelerate the total volume and percentage of recycled water (Municipal Waste Water Recycling Survey, 2014).

(Municipal Waste Water Recycling Survey, 2014).

Another point that will be made to the EDH City Council is that in addition to recycling water from residential, commercial, and industrial sources, the goal will be to include surface water augmentation and direct potable reuse as part of the overall operational process. Surface water augmentation is the process of adding wastewater to surface water reservoirs. Direct potable reuse takes recycled municipal wastewater directly to potable water supply lines. Presently neither process is widely used in California but could further increase the value of additional wastewater recycling plants. In fact, a pilot is currently being planned to explore the feasibility of incorporating surface water augmentation (Municipal Waste Water Recycling Survey, 2014).

Wastewater Recycling Plant Design

The proposed recycling plant will be designed similar to the Bundamba plant. The Bundamba plant for example processes water from the Oxley, Wacol, Goodna, and Bundamba waste water treatment plants. The following processes will be part of the proposed operational strategy. The first objective will be the identification of local source waters in El Dorado and other approved city-partners. The second objective will be the development of the facility which will include a 24 hour-a-day control room, Pre-treatment, microfiltration, Reverse Osmosis, UV-Advanced Oxidation, Water Quality Analysis, Remineralisation, Pure Water Storage and Pipeline, Nitrogen Removal, Residuals Treatment, Concentrate water release, and Sludge Removal (Bundamba Purified Recycling Water Tour, 2013).

Each step of the Wastewater recycling process is vital. Within the pre-treatment process pheric chloride acts as a coagulant, reacting with traces of dissolved phosphate. This chemical ultimately binds suspended particles into clumps which settle at the tank bottom. A chlorine residual chemical is also added to prevent algo growth. There will be electronic checklists that will be evaluated by plant operators during each step of the purification process. The Sludge removal process empties into large binds and is transported to appropriate landfills by trucks. In this part of the process careful attention must be given to the Centrifuge machine to ensure that the solid residue is dewatered and thickened. This will minimize the weight when dumped at the landfill thereby decreasing cost (Bundamba Purified Recycling Water Tour, 2013).

During the microfiltration process it is essential that particles such as silt, protozoa cyst, bacteria, and viruses are filtered out by the 1000’s of hollow fibers. Additionally, the process for backwashing must be automatic and preset to occur every 30 minutes. The Reverse Osmosis process is critical because it eliminates compounds such as salt, organic compounds, and micro-organisms. The special plastic membrane sheets used for this process must be carefully monitored to ensure they remains in good working order (Bundamba Purified Recycling Water Tour, 2013).

Nitrogen removal is a process that occurs during several phases. The first stage (anitorphication) transforms the ammonia into nitrate. The second stage converts the nitrate into nitrogen gas and is referred to as De-Nitrification. Additionally, the UV Advanced Oxidation process destroys trace organic material not previously eliminated by the previous filters (Bundamba Purified Recycling Water Tour, 2013).

Also, preparation and redundancy are essential to effective operations and plant management. Therefore the plant will have a large number of lift stations and back-up power sources to reduce the possibility of sewage back-up. Also, there will be a variety of power generation sources including electric and diesel engine (Wastewater Treatment Plant Tour-"Flush to Finish", 2010).

The control room will have a high-tech computer system that monitors information like PH, Tepidity, Chlorine, and water temperature. Field data will be collected using a mobile device similar to Field Data Pro Mobile. Each information point will have a scanning barcode that enables inspection information to be uploaded to the main database. This will enable timely analysis of potential issues such as equipment problems, out of limit data points, and system utilization concerns (Water Recycle Plant Uses Handheld Computers to Improve Operations, 2011).

Although not comprehensive, below is a list and description of technologies approved by the United States Environmental Protection Agency. These technologies have subsequently been recognized as innovative, and effective in the Wastewater recycling process. The administration of the proposed wastewater recycling plant intends to mitigate potential risks by evaluating and implementing technology from the list below. Associated costs are provided based on the level of disclosure by the vendors.

Water Quality and Regulation Standards

Water quality and regulation standards are established by the EPA. One example is the Ground Water Rule (GWR), which seeks to mitigate risks of contaminating lakes, reservoirs, and aquifers. Established in 2006 the four components of the risk mitigation process that facilities like a wastewater recycling plant must consider include:

• Periodic sanitary system surveys to examine eight essential elements of public water systems and any associated deficiencies. So for example when considering the location of the wastewater recycling plant placing it near a leaking septic system would be something to be avoided.
• Triggered source water monitoring must ensure that at the plant 99.99 percent of viruses and other bacteria, contaminants are properly removed. Appropriate documentation and storage of such information must be secure and available in the event of an audit. Additionally, protocols must be in place to properly and immediately address non-compliance. One example is the temporary suspension of a source water location until the non-compliance issue is properly addressed.
• Corrective steps are essential for a system with significant deficiency or evidence of source water fecal contamination; and
• Compliance monitoring to ensure treatment technology in the Plant consistently removes or inactivates 99.99 percent of viruses. Filters, pipes, and any other facility mechanical devices/technology must have serviceable logs to address identified issues.

(Water: Ground Water Rule, 2012)

Conclusion

In conclusion, the necessity of waste water recycling is based on factors such as droughts, expanding population, and the subsequent high-demand for a precious natural commodity. The proposed process for developing a wastewater recycling plant in El Dorado, Ca. has been communicated. The financial facilitation of such a process is mitigated with State incentives and funding specifically targeted for water projects. In addition, the proposed taxation on nearby cities to handle their Wastewater overflow will further minimize costs.

With the increase in water regulation standards from organizations like the EPA, wastewater must be properly filtered, and each element appropriately disposed. Therefore the establishment of a recycling plant that adheres to such standards is the best solution for local communities. Not only does it support community needs but it ensures the natural resources are properly cared for. For example, if wastewater is improperly dumped in areas of vegetation then it affects the food that we eat and increases virus and bacteria contamination. If wastewater that has not been appropriately recycled gets in local ground water sources, animals can drink the water and get sick.

Finally, although infrastructure and engineering costs will be based on a number of variables, proposals have been made to mitigate potential costs. In the proposal of such a large undertaking, community and Government support are vital. The Government and the community of El Dorado have both indicated a desire and willingness to create Wastewater recycling plants thereby removing many of the hurdles that would have otherwise been present. With this understanding the probability of approval by the city council is greatly improved.

References

(2010). Wastewater Treatment Plant Tour-"Flush to Finish". [ONLINE] Available at: https://www.youtube.com/watch?v=pRaptzcp9G4. [Last Accessed 28 September, 2014].

(2011). Water Recycle Plant Uses Handheld Computers to Improve Operations. [ONLINE] Available at: http://info.ncsafewater.org/Shared%20Documents/Spring%20Conference/2011%20Presentations/ST_M_PM_03.45_Young.pdf. [Last Accessed 28 September, 2014].

(2012). Water: Ground Water Rule. [ONLINE] Available at: http://water.epa.gov/lawsregs/rulesregs/sdwa/gwr/basicinformation.cfm. [Last Accessed 28 September, 2014]