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HomeMy WebLinkAboutAgenda- 02-19-2019 12-3 - Information Item - Memorandum - Greywater and-or Reclaimed Water Systems 1 ORANGE COUNTY NORTH CAROLINA MEMORANDUM TO: Board of County Commissioners Bonnie Hammersley, Orange County Manager Travis Myren, Orange County Deputy Manager CC: Quintana Stewart, Orange County Health Director Victoria Hudson, Orange County Environmental Health Director Michael Rettie, Orange County Chief Building Official FROM: Craig N. Benedict, Orange County Planning Director DATE: February 19, 2019 SUBJECT: BOCC Information Item- Greywater and/or Reclaimed Water Systems An inquiry was posed at the BOCC of December 2018 regarding OWASA's `greywater' system. The nomenclature of `greywater' often can be confused with other non-potable water such as `reclaimed water systems'. OWASA's system is in this latter category. Attachment 1 is a 2 page explanation regarding their reclaimed water system. This reclaimed water system (RWS) uses a byproduct of advanced treatment of waste water from their sewer treatment plant. There are other water conservation measures such as `rainwater harvesting' that relate more closely to `greywater' wherein OWASA recognizes that private individuals may collect rainwater and discharge the flow (in part) to the wastewater stream (i.e. unmetered non-potable water). OWASA has a resolution (attachment 2) that addresses this related policy. To round out the use and application of `greywater' or `reclaimed' water system, I have attached a joint memo from the Building Division and Environmental Health which addresses how the implementation and implication of such systems are addressed by the state regulatory codes (Attachment 3). Attachments: 1. Attch 1- OWASA explanation regarding their reclaimed water system 2. Attch 2- OWASA resolution for rainwater harvesting systems 3. Attch 3- Joint Memo from Building and Environmental Health Attachment 1 2 ORANGE WATER AND SEWER AUTHORITY RECLAIMED WATER SYSTEM June 2018 PURPOSE: To provide information about OWASA's reclaimed water(RCW) system. BACKGROUND: OWASA and the University of North Carolina at Chapel Hill (UNC) partnered to develop the RCW system to provide UNC with a capability to use RCW instead of drinking water to meet certain non-potable water demands (chilled water, irrigation of landscaping and athletic fields, toilet flushing in new facilities, etc.) on the campus. RCW is the clean water produced as a by-product of the advanced treatment of wastewater at OWASA's Mason Farm Wastewater Treatment Plant (WWTP). UNC paid the entire cost to build the RCW system, excluding the $1.6 million in grant funds OWASA received from the North Carolina Clean Water Management Trust Fund to pay for engineering design and permitting costs, and $625,500 OWASA received from EPA which helped pay for construction of the system. The system cost about $14 million to design and build. Upon completion, the RCW capital improvements were dedicated to OWASA for operation and maintenance. OWASA'S OPERATION: The RCW water system began operation in April 2009. Calendar Year 2017 RCW sales averaged 0.72 million gallons a day(MGD),about 10.6%of the community's water needs. The system includes a 600,000 gallon concrete storage tank and a pumping station located at the WWTP. The RCW system also includes a chemical feed system that allows OWASA to further treat and disinfect the already highly treated reclaimed water. The RCW distribution system is comprised of about five miles of RCW mains ranging in size from 6 to 24 inches in diameter. The RCW system is currently configured to meet a total peak day demand of 3 MGD(average daily demand of 1.2 MGD); however, the system is designed and constructed to allow cost-effective expansion to 5.2 MGD by adding only an additional transfer pump and additional chemical feed system capacity. The RCW average daily demand forecast for Fiscal Year 2018 is 0.68 MGD. Demands are expected to increase to about 0.93 MGD by 2030. The system's current configuration is expected to meet projected RCW demands for the foreseeable future. The cost to operate and maintain the system is paid solely by OWASA's RCW customers which currently includes only UNC (including UNC Healthcare) and the Saint Thomas More School. PRIMARY BENEFITS OF THE RCW SYSTEM: • Enables OWASA to meet non-potable water needs in a cost-effective manner while freeing up the community's drinking water supply and treatment capacities to meet essential needs; • Lowers the risk(for all customers)during future droughts; • Defers the need for costly additional water supply and/or treatment facilities; and • Reduces the amount of energy OWASA uses to meet UNC's non-drinking water needs. FUTURE EXPANSION OF THE SYSTEM: OWASA's 2010 Long-Range Water Supply Plan concludes that investing OWASA funds in an expansion of the RCW system to promote further conservation of OWASA's drinking water supply sources is less cost-effective than other water supply management options identified in the plan. Instead, the plan concludes that OWASA remain "opportunistic"on a case-by-case basis with respect to customers seeking to extend or connect to the RCW system. FOR MORE INFORMATION: Monica Dodson,Wastewater Treatment and Biosolids Recycling Manager mdodson(cr�,owasa.org or 919-537-4205 3 QWASA Reclaimed Water Systems ' Pam- � T °E �` _ p Legend l nA _ �Reclaimetl Water April 201 V (�y(p(l —\Y f Tr T 4 ��� �—� _ -Chiller Plants M Toilet Flushing Facility -UNC Inlgetion�. Areas = Non-VNCCustamers _ 1 �N \� ,� an c � � r staai ��� nn� ainmpr i N Pr --r'YYiI eld I I Saint+inaa M¢re School 1� �4 n /211 1 yrW0 1 L �r 000 11 �A C3 sa mntLj I • os soo sac l 11 inch = 300 feet YJ4YfP L a tsa azF r 4 Attachment 2 RESOLUTION APPROVING OWASA'S RAINWATER HARVESTING SYSTEMS REQUIREMENTS AND CHARGES WHEREAS, Orange Water and Sewer Authority (OWASA) highly values water use efficiency and strongly encourages water conservation practices by all customers; and WHEREAS, "rainwater harvesting" (the collection, storage, treatment, and use of rainwater for beneficial purposes) helps to conserve our essential drinking water supplies and reduce demand on our reservoirs, provide increased capacity and security, reduce the rate and volume of stormwater runoff and maintain site-scale hydrologic balance, and can have an important role in permaculture design; and WHEREAS, rainwater harvesting systems and other non-potable water supply systems have the potential to result in wastewater discharges to the OWASA sanitary sewer system, thereby requiring the collection and treatment of those discharges at a cost to OWASA; and WHEREAS, OWASA services are paid for by OWASA's customers through rates and fees, and under the legal requirement that "there will be no free service rendered" and that charges for service will reflect the cost that OWASA incurs to provide that service; and WHEREAS, OWASA wishes to implement a simple and straightforward administrative process for determining, applying, and collecting the charges applicable to the collection and treatment of wastewater resulting from rainwater harvesting systems and other non-potable water systems; and WHEREAS, OWASA wants to ensure that rainwater harvesting systems and other non-potable water supply systems used within its service area are designed, operated and maintained to protect public health and the safety and integrity of our water and wastewater systems; NOW, THEREFORE, BE IT RESOLVED BY THE BOARD OF DIRECTORS OF ORANGE WATER AND SEWER AUTHORITY: 1. That the Board of Directors authorizes and directs staff to apply sewer charges to wastewater discharges resulting from rainwater harvesting and other non-potable water supply systems provided that the minimum threshold for which the charges shall apply is 3,000 gallons per month. Individually-metered single family residential customers with such systems are hereby deemed to fall below the threshold. 2. That this policy shall become effective upon adoption. 3. That the Executive Director is authorized and directed to implement and interpret this policy and incorporate it into OWASA's Standards and Specifications. Adopted this 13th day of September, 2007. Michae . ac)Clarke, Chair AT T: on e , 5 OWASA Rainwater Harvesting Systems Requirements and Charges General Requirements: Rainwater harvesting is the collection and storage of rainwater from roofs or other catchment areas for future use. This stored rainwater may be for internal use within a building(flushing of toilets, etc.) or may be for external purposes such as irrigation. OWASA encourages conservation of water through the use of rainwater harvesting systems by OWASA customers provided the following standards and specifications governing their use are met to protect the safety and integrity of the public water and sewer systems: o Rainwater collection devices or cisterns that are capable of being fed from both a rainwater harvesting system or alternately from OWASA's Potable Water System must be designed, built, operated and maintained to ensure that the OWASA drinking water system is protected from cross-connection and contamination. This shall be accomplished by the installation of an air gap at the point where the potable water discharges into the non-potable water collection device. Air gap physical separation shall be at least double the diameter of the supply line measured vertically above the overflow rim of the containment device, but in no case shall it be less than 1 inch. o Piping for rainwater harvesting systems shall be separate from any potable piping system (includes both domestic and/or fire suppression systems which use water supplied by OWASA). A physical separation of piping is required between any potable and non-potable water system. The use of backflow devices to separate two piping systems is not allowed. There must be an air gap. o A detailed written description of a proposed rainwater harvesting and plumbing system shall be submitted to OWASA Engineering Staff for review and consideration. This shall include narrative sufficient to explain how the proposed system will operate along with plumbing drawings detailing potable water piping and harvested rainwater piping. All air gaps between potable and non-potable piping systems must be clearly indicated on drawings. o No rainwater harvesting system or other non-potable water supply system shall be installed and used by a customer connected to the OWASA Potable Water System and/or the Sanitary Sewer System unless first reviewed and approved by OWASA. For rainwater harvesting systems that will directly or indirectly result in the generation of wastewater to be discharged to the OWASA Sanitary Sewer System, OWASA will allow and accept such discharges provided they fully meet the requirements of OWASA's Sewer Use Ordinance. 6 OWASA Rainwater Harvesting Systems Requirements and Charges September 7,2007 Applicable Sewer Service and Commodity Charges: Rainwater harvested solely for irrigation or other uses which do not introduce flows into OWASA's Sanitary Sewer System shall not be subject to any OWASA sewer charges. OWASA's sewer charges shall be applicable to rainwater harvesting systems or other non-potable water supply systems that result in a wastewater discharge of 3,000 gallons or more per month to the OWASA Sanitary Sewer System. (Effectively, individually- metered single family residences connected to the OWASA Sanitary Sewer System would not incur a charge for use of the rainwater harvesting system or other similar system.) The applicable sewer charges will be calculated to fairly and equitably recover the costs of collecting and treating the portion of the harvested rainwater that is being discharged into the OWASA Sanitary Sewer System. OWASA will bill the customer for those services on a monthly basis, and the applicable charges will be shown as a component of the monthly bill sent to the customer. Sewer charges shall be subject to periodic increases to reflect the current cost-of-service, as determined by OWASA. OWASA will use either of the following methods for determining sewer charges applicable to rainwater harvesting systems or other non-potable water supply systems: 1. Sewer Charges Applicable to Unmetered Discharges From Rainwater Harvesting Systems: OWASA may, at its discretion, determine that a separate meter does not need to be installed to measure the actual volume of discharge to the OWASA Sanitary Sewer System that the rainwater harvesting system or other non-potable water supply system may cause. For such cases where the estimated volume is 3,000 gallons or more per month, OWASA will determine and levy a flat monthly sewer charge based on the estimated average wastewater discharge anticipated from those plumbing fixture units that would be supplied by the rainwater harvesting system or other non-potable water supply system. This would assume a certain volume of the harvested rainwater is used for these plumbing fixtures each month. In order for the service location to be eligible for this option, and for OWASA to estimate the expected volume and determine the applicable charge, the builder/owner/occupant must provide the following information to OWASA: (1) a list of the plumbing fixtures discharging to the OWASA Sanitary Sewer System that are supplied by the rainwater harvesting system or other non- potable water supply system; 2 7 OWASA Rainwater Harvesting Systems Requirements and Charges September 7,2007 (2) a table showing the plumbing fixture unit values or applicable use volumes per unit of use for each of the plumbing fixtures discharging to OWASA Sanitary Sewer System; (3) a calculation of the anticipated daily use of each plumbing fixture; and (4) a calculation of the estimated daily and monthly wastewater volume that will be discharged by these plumbing units. Once this information has been received, OWASA will determine the flat rate that will be applicable to the estimated sewer discharge for the facility. 2. Sewer Charges Applicable to Metered Discharges From Rainwater Harvesting Systems: At the builder/owner/customer's request, or as otherwise determined necessary and required by OWASA, the customer shall at their expense install a special flow measurement system to accurately determine the volume of wastewater that is actually discharged to the OWASA Sanitary Sewer System as a result of a rainwater harvesting system or other non-potable water supply system. Such a measurement system would not include the volume of water used for irrigation/outside uses that do not result in a discharge to the OWASA Sanitary Sewer System. Under this alternative method: (1) The meter or flow measurement system would have to be designed and built according to OWASA standards, be accessible to OWASA meter reading and maintenance personnel, and have a remote meter readout installed in an accessible location. OWASA will own and maintain the meter installed for this purpose. (2) OWASA would bill the customer for the actual measured volume of sewer discharge, as well as a fixed monthly service charge for billing the customer and maintaining the sewer-only meter or flow measurement system. This would provide for an accurate measurement of the discharge to the sewer system, and cover OWASA's full costs of reading and maintaining the sewer-only meter as well as collecting and treating the wastewater discharge. In general, to reduce total costs to the customer and provide for ease of administration, OWASA's preferred approach will be to base the applicable sewer charges on the estimated volume of wastewater discharge. However, metering of the actual sewer discharge may be necessary for large volume systems. 3 Attachment 3 8 PLANNING & INSPECTIONS DEPARTMENT Michael D. Rettie, Chief Building Official Building Inspections 131 W. Margaret Lane (919) 245-2600 Suite 101 (919) 644-3347 (FAX) ORANGE COUNTY P. O. Box 8181 www.orangecountync.gov NORTH CAROLINA Hillsborough, NC 27278 Non-potable water system. Relevant definitions from State Code: NON-POTABLE WATER. Water not safe for drinking, personal or culinary utilization. [RP] POTABLE WATER. Water free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming in bacteriological and chemical quality of the Public Health Service Drinking Water Standards or to the regulations of the public health authority having jurisdiction. [RP] RAINWATER. Water from natural precipitation. GRAY [GREY]WATER. Gray water is all wastewater that is discharged from plumbing points of use, except toilet water. Gray water commonly contains soap, shampoo, toothpaste, food scraps, oils, detergent, and hair. Not all gray water is equally gray. High load gray water consists of the kitchen and washing machine discharges. Low load comes from showers, tubs, and hand sinks. RECLAIMED WATER. Nonpotable water that has been derived from the treatment of waste water by a facility or system licensed or permitted to produce water meeting the jurisdiction's water requirements for its intended uses. Reclaimed water is collected or diverted and treated prior to being distributed. This means that the water is treated to a level for uses less than the drinking water standards. This is also known as "Recycled Water." Water that does not meet "potable" requirements commonly are referred to as: "non- potable," "gray water," "recycled water," "reclaimed rainwater," or "salvaged water." All may be used for specific purposes in North Carolina. Non-potable "untreated" rainwater (only) uses include: 1. Outdoor irrigation, 2. Decorative fountains, 3. Yard Hydrants, 4. Industrial processes, 5. Vehicle washing, and 6. Outdoor hose bibs (not routed through building wall). 9 Non-potable water, that is disinfected and filtered, uses include: 1. Toilet flushing; 2. Urinal flushing; 3. Evaporative cooling tower make-up; 4. Trap primers; 5. Fire suppression systems; 6. Clothes washers; 7. Outdoor pools and spas; and, 8. Hose bibs — Residential (Only). On-site non-potable water may be collected from the following sources only: 1. Bathtubs, 2. Showers, 3. Lavatories, 4. Clothes washers, and 5. Laundry trays. Prohibited water sources include: 1. Reverse osmosis reject water, 2. Water softener backwash, 3. Kitchen sink, 4. Dish washer, and 5. Waste water containing fecal matter or urine. Non-potable water systems require a separate water piping system that is clearly identified as not suitable for potable purposes. The drainage piping used to collect Non- potable water, for utilization, must comply with Plumbing Code. Non-potable water intended for on-site use will require disinfection, treated or both as determined by a licensed Design Professional, if the intended end-use application requires such treatment, see "reclaimed rainwater." Non-potable water that is untreated may be retained on site, in collection reservoirs, for not more than 24 hours. The North Carolina State Codes require all buildings or premises where plumbing fixtures, equipment, or appurtenances intended or required to utilize potable water are installed, shall be connected to a public or private potable water source. NCGS 130A- 335 requires anyone owning or controlling a residence, place of business or a place of public assembly must have an approved wastewater system. All wastewater from water- using fixtures and appliances connected to a water supply source discharges to the approved wastewater system. A wastewater system may include components for collection, treatment and disposal of wastewater. Gray water or rain water recycling shall be installed in compliance with the Plumbing Code. The 15A NCAC 18E Wastewater Treatment and Dispersal Systems (2018) are in the final stages of approval with the Commission for Public Health and may be effective in the very near future. The new Rules for Onsite Water Protection include updated verbiage to address reclaimed water systems. For the purposes of the administrative 10 code, reclaimed water systems are defined as, "treated wastewater effluent meeting established standards and using the effluent for beneficial reuse." Beneficial reuse intends to conserve the State's water resources by reducing reliance on potable, surface, and groundwater resources for activities where water would not be a contamination risk by the consumption of humans and animals. Industry stakeholders advocated the addition of reclaimed water systems to the proposed rules. According to the fiscal statement, there is an increased cost associated with treating the wastewater to a higher effluent standard. Reclaimed water systems, though, allow the owner a cost savings with regards to the use of potable water, citing businesses like golf courses and industries that need large amounts of water for cooling. Environmental Health has the capacity to review, to permit, and to inspect reclaimed water systems as a type of advanced pretreatment system for any applicant who is not served by public wastewater utility.