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HomeMy WebLinkAboutMetro / JPA Executive SummaryMETRO WASTEWATER J PA WATER REUSEANDSECONDARY EQUIVALENCY FOR POINT LOMA WASTEWATER TREATMENT PLANT UPDATE: AUGUST 19, 2013 EXECUTIVE SUMMARY The Point Loma Wastewater Treatment Plant ("PLWTP") is operated by the City of San Diego and currently serves the City of San Diego and 12 member agencies throughout the County. PLWTP is permitted to treat up to 240 million gallons of wastewater a day and has operated at levels greater than 190 mgd while meeting or exceeding all general and specifically negotiated regulatory requirements necessary to maintain a modified permit thereby allowing it to remain as an Advanced Primary treatment plant. Members of the Metropolitan Wastewater Joint Powers Authority ("JPA") believe that permanent acceptance of a smaller PLWTP considered Secondary Equivalent can be achieved through development and implementation of a comprehensive, systematically implemented Regional Water Reuse Plan. This Plan must be undertaken programmatically toincrease public awareness, further catalyze customer action through individual water conservation and water reuse; consider opportunities for stormwater capture and the use of graywater and rainwater; expand recycled water opportunities; and implement a variety of agency -specific and collaborative large-scale water reuse projects including Potable Reuse resulting in a significant off-loading of the treatment demand on PLWTP. A successful effort would secure state and federal legislation accepting a smaller PLWTP as secondary equivalentthus making future plant upgrades unnecessary. This success would avoid, on behalf of our ratepayers,anestimated $3.5 billion dollar capital/financingexpense of upgrading PLWTP to secondary treatment (not to mention millions of dollars in increased annual operating costs). Creating potable water as part of the Plan could also alleviate potable water demands to such a degree as to avoid or downsize currently planned water supply and transportation projects(avoiding another several billions of dollars in capital, operating, and energy costs, as well as carbon generation). THE CASE FOR SECONDARY EQUIVALENCY AT POINT LOMA City of San Diego Water and Wastewater Utilities The current practice of the City of San Diego ("the City") is to procure raw water, treat it to drinking water standards and distribute it throughout the City. The City also collects and treats wastewater for its residents and businesses and for a number of other agencies ("Participating Agencies") and discharges that treated wastewater into the ocean. These Participating Agencies make up about 35% of the flow in the system and are represented by the Metro Wastewater Joint Powers Authority ("JPA") which is comprised of the County of San Diego (representing County Sanitation Districts) and the 1 08/19/13 8:00a.m. 4 cities of Chula Vista, Lemon Grove, El Cajon, Coronado, Del Mar, Imperial Beach, La Mesa, National City, and Poway, as well as the Otay and Padre Dam Water Districts. The City wastewater system also produces reclaimed water for use in irrigation and industrial purposes, and distributes it through a separate piping system (purple pipe). The City's wastewater system consists of the following Municipal and Metropolitaninfrastructure: a Municipal wastewater system of pipelines and pump stations that collects and sends wastewater to the Metropolitan (Metro) wastewater system for treatment and discharge to the ocean. The Metro system consists of • several large pipelines and pump stations, • three treatment plants, • a biosolids (sludge) processing plant (the Metro Biosolids Center) and • two ocean outfalls. The Point Loma Wastewater Treatment Plant ("PLWTP") is permitted as a240 million gallons per day ("mgd") advanced primary (chemically enhanced) plant which discharges treated wastewater through the Point Loma Ocean Outfall ("PLOO") 4.5 miles out in the ocean in 320 feet of water. The North City Water Reclamation Plant ("NCWRP") is a 30 mgd Tertiary Treatment plant that produces reclaimed water. Since the NCWRP does not have its own outfall, wastewater not needed for reclaimed water customers is treated to a secondary level and pumped to the PLWTP. Additionally, the South Bay Water Reclamation Plant ("SBWRP") is a 15 mgd Tertiary Treatment plant that produces reclaimed water. Wastewater not needed for reclaimed water customers is treated to a secondary level and discharged through the South Bay Ocean Outfall ("SBOO") 3.5 miles out in the ocean in 90 feet of water. Wastewater Treatment Wastewater treatment is basically the process of removing solids from the wastewater. All treatment plant processes typically begin with screens to remove debris such as pieces of wood, followed by removal of grit (mainly sand). A Primary treatment plant then removes about 60% of the solids which are heavy enough to settle out of the wastewater by gravity. Advanced Primary treatment plants such as the PLWTP then use chemicals to cause lighter solids to clump together and settle out by gravity. The PLWTP removes at least 88% of the solids. A Secondary treatment plant has a primary level of solids removal followed by a biological treatment which removes lighter biological matter in the wastewater ultimately removing about 90% of the solids. A Tertiary treatment plant, like the NCWRP and the SBWRP, has both Primary and Secondary treatment followed by filtration such as through anthracite coals beds resulting in the removal of about 99% of the solids. 2 08/19/13 8:00a.m. 5 The required levels of treatment are typically measured by Total Suspended Solids ("TSS") and Biological Oxygen Demand ("BOD"). The BOD is a measure of how much dissolved oxygen the treated wastewater might remove from the receiving water, such as the ocean. The City has many years of monitoring data which indicates the BOD discharge from the PLWTP has no negative impact on the ocean environment. Wastewater Treatment Regulation The federal Clean Water Act passed in 1972 required that all wastewater treatment plants be permitted. The permitting process in California involves the Environmental Protection Agency ("EPA"), the local Regional Water Quality Control Board ("RWQCB"), the State Water Resources Control Board and the California Coastal Commission ("CCC"). The Clean Water Act also required wastewater treatment plants to treat wastewater at least at a secondary level. The actual required treatment is based on what is needed to protect the receiving waters, such aslakes, rivers and the ocean. A number of dischargers are required to go to higher levels of treatment than secondary. Several years after the Clean Water Act was enacted, it was amended to allow dischargers to receive a modified permit (waiver of secondary) if dischargers could demonstrate they could safely discharge wastewater to the receiving water at a treatment level lower than secondary such as Advanced Primary. In practice,permits were based on what was actually needed to protect the receiving waters --secondary in many cases, above secondary in other cases and below secondary in some cases. Initially, the City of San Diego applied for a modified permit for the PLWTP but later withdrew the application and began planning to convert the PLWTP to secondary. Subsequently the window of time in the Clean Water Act for applying for a modified permit closed, and the EPA and several environmental groups sued the City for not being at secondary at the PLWTP. In 1994, the federal Ocean Pollution Reduction Act ("OPRA") was passed. OPRA was sponsored by then -Congressman Filner and provided an opportunity for the City to apply for a modified permit for the PLWTP. In return, the City agreed to construct 45 mgd of reclaimed water capacity. This resulted in the construction of the NCWRP, the SBWRP and the SBOO. The City applied for and was granted a modified permit for the PLWTP in 1994. Point Loma Wastewater Treatment Plant Permits The City must apply for a new permit or modified permit every five years for the PLWTP. In order for the local environmental community not to oppose the City's application for the modified permit sought every five years, the City agreed to do a number of studies. Each study was reviewed by environmental groups and their experts. The City conducted a refined estimate of costs to convert the PLWTP to secondary. The PLWTP is hemmed in by the Navy, the Cabrillo National Monument, the ocean and a cliff. This leads to higher costs for the addition of Secondary Treatment. The initial study indicated a capital cost of $1 billion which has recently been escalated to $1.4 billion in today's dollars, not including financing costs. With financing, current estimates top $3.5 billion. In addition, Secondary Treatment requires a great deal of electricity. Annual operating and energy costs are estimated to increase by about $44 million annually. 3 08/19/13 8:00a.m. 6 The City also conducted a comprehensive review of its OceanMonitoring Program. In order to apply for a permit, dischargers must demonstrate the effect of their discharge on the receiving water. The City continuously collects data from the ocean near the discharge point of the outfall, measuring impacts on sediments, water quality, and aquatic and plant life. The City hired experts from well-known scientific organizations such as Scripps and Woods Hole to review the Ocean Monitoring Program and provide recommendations to make it more comprehensive. All the recommendations were implemented. The City also agreed to conduct studies and projects to optimize wastewater reuse, although it was already producing reclaimed water at the NCWRP and the SBWRP. The Recycled Water Study looked at the feasibility of expanding recycled water use and producing potable water from wastewater. The Recycled Water Study concluded that since most of the recycled water uses in the area were seasonal irrigation requiring separate pipelines from the existing water system, increasing wastewater reuse would be more productive through pursuing potable reuse. Potable Reuse can be either Indirect or Direct Potable Reuse. • Indirect Potable Reuse ("IPR") includes advanced treatment of wastewater indirectly entering a water treatment plant after being detained, for example, in a drinking water reservoir. • Direct Potable Reuse ("DPR") sends advanced treated wastewater directly to a water treatment plant. The Recycled Water Study outlined a concept whereby almost 100 mgd of wastewater otherwise planned to be treated at the PLWTP could be diverted upstream of the PLWTP to either Advanced Water Purification Facilities (IPR) or to South Bay wastewater treatment plants for Secondary Treatment before ocean discharge. This would allow the permitted capacity of the PLWTP to be reduced from 240 mgd to 143 mgd. The City then looked at the feasibility of treating wastewater to a potable level through an IPR process. A 1 mgd demonstration project was conducted at the NCWRP and a study was made of San Vicente Reservoir. The study and demonstration project showed that wastewater could be treated at the NCWRP to a level sufficient for safe discharge to San Vicente Reservoir for subsequent treatment at a water treatment plant. Although the demonstration project did not include actual placement of the water into the Reservoir, the data showed that the treated water to be placed in the Reservoir would be of a higher quality than that of current raw water sources. Additionally, final potable water produced at the demonstration site was of a quality similar to distilled water. The current modified permit for the PLWTP expires on July 31, 2015. The application for a new permit must be submitted no later than January 2015. It takes approximately one year to collect and assemble the data required for the permit application.That process is expected to start in January 2014. THE CASE FOR POTABLE REUSE AS A STRATEGY Potable Reuse/Secondary Equivalency Program Concept 4 08/19/13 8:00a.m. 9 The San Diego region is semi -arid and needs the most cost effective and diverse system of water supply it can achieve. Potable water reuse of wastewater, either Indirect or Direct, appears to be a competitive choice in producing a new water supply. The region also needs a wastewater treatment system that protects the ocean environment. The capital and operating costs of providing additional water for the region will have a significant impact on water ratepayers. In addition, if the City is ever required to convert the PLWTP to Secondary Treatment, the capital and operating costs would likewise be significant to the wastewater ratepayers. In almost every case, water and wastewater ratepayers are the same people, although they may be serviced by different agencies. By considering combined water supply and wastewater treatment needs, there is an opportunity to reduce the impact to ratepayers by billions of dollars in capital and financing costs, and tens of millions of dollars in annual operating and energy costs. An additional benefit would be a reduction in environmental impacts because much Tess energy production would be needed. The Recycled Water Study outlines a concept whereby about 100 mgd of actual and planned wastewater flow is diverted upstream from the PLWTP to either potable reuse or to South Bay wastewater treatment plants for secondary treatment before ocean discharge. This concept creates 83 mgd of potable water. The solids discharged and the environmental impact of a 143 mgd Advanced Primary Plant at Point Loma would be similar to or less than that of a 240 mgd Secondary Plant thereby constituting Secondary Equivalency. The current PLWTP permit allows discharge of 13,598 metric tons of solids per year. If the 240 mgd PLWTP was converted to secondary, the discharge would be 9942 metric tons per year. At current solids removal rates and a flow of 140 mgd, the discharge rate at the PLWTP would be very close to 9942 metric tons per year. Thus, if the current PLWTP solids discharge criteria was capped at 9942 metric tons per year, it would be equivalent to a secondary 240 mgd plant. This could be achieved at a flow of approximately 140 mgd. Historically, the PLWTP has discharged over 11,000 metric tons of solids to the ocean with no detrimental impact to the ocean environment. Since the historic flows through the PLWTP have exceeded 190 mgd and 11,000 metric tons of solids per year, and the comprehensive Ocean Monitoring Program has shown no detrimental impact to the ocean environment, there would be no value in converting the remaining flow at the PLWTP to secondary while incurring billions of dollars in ratepayer costs. Even converting a smaller 143 mgd PLWTP would result in billions of dollars in capital costs, tens of millions in annual operating costs and the environmental impacts of producing the energy to operate the secondary plant. Rather than planning for one wastewater or water project at a time, the region's needs for wastewater treatment and additional water supply should be planned programmatically together over a longer period of time. Conceptually, almost 100 mgd of potable reuse and diversion of wastewater to South Bay could be implemented over a specific timeframe and combined with lowering the permitted solids discharge of the PLWTP to 9942 metric tons/year, for example. In return, action would be taken to accept a smaller PLWTP as a Secondary Equivalent. Like all wastewater treatment plants, the PLWTP would still be required to get a new permit every five years and demonstrate through the City's comprehensive monitoring program that it is not harming the ocean environment. 5 08/19/13 8:00a.m. CONCLUSION As representatives of our region's ratepayers, we are at a critical juncture. The choices we make as a result of actions we takeor, perhaps, opportunities missed due to our inaction, will have environmental and fiscal ramifications for many generations to come. The Metropolitan Wastewater JPA supports the development of a Regional Water Reuse Plan so that both new, local, diversified water supply including potable reuse is created and substantial offload at Point Loma is achieved to support state and federal legislation accepting a smaller PLWTP as a Secondary Equivalent. Success ultimately minimizes wastewater treatment costsand lessens the need for new water supply sources and larger water transportation systems due to expanded water reuse thereby most effectively applying ratepayer dollars. Metro JPA Goal: Create a regional water reuse plan so that both a new, local, diversified water supply is created AND substantial offload at Point Loma is achieved to support legislation for permanent acceptance of Point Loma as a smaller secondary equivalent plantthat continues to protect the ocean environment. Minimize ultimate Point Loma treatment costs and most effectively spend ratepayer dollars through successful coordination between water and wastewater agencies. 6 08/19/13 8:00a.m. q