Permit Evaluation and Overview

Transcription

1 Permit Evaluation and Overview Oregon Department of Environmental Quality Water Quality Division 811 SW Sixth Avenue Portland OR Contact: Ron Doughten Proposed permit DEQ proposes to issue a new Water Pollution Control Facilities (WPCF) general permit for the direct use of wastewater generated from industrial activities. The permit identifies two categories of industrial reuse water (Category I and Category II) that without secondary or advanced wastewater treatment are suitable for reuse, based on measured or expected water quality characteristics. Proposed uses of industrial reuse water allowed under the permit include seasonal irrigation, as a water source in non-residential landscape ponds, and limited industrial, commercial, or construction uses. A person proposing to use industrial reuse water in the environment, in lieu of discharge to a sanitary sewer, onsite wastewater treatment system, or surface water discharge under a NPDES permit, may register under this permit [ORS 468B.050]. Permit writer Ron Doughten, Telephone Number , doughten.ron@deq.state.or.us Permit category 2501 WPCF General Permit Activities requiring registration under this permit This permit authorizes the reuse of up to 25,000 gallons per day of industrial reuse water originating from industrial sources. Sources identified as Category I industrial reuse water must register under this permit. Category I industrial reuse water includes water sources that may have been concentrated or slightly degraded by industrial activities, but have no added detergents or chemicals (such as but not limited to corrosion inhibitors, antifreeze compounds, and biocides) except chlorine. Sources of Category I industrial reuse water include, but are not limited to: reverse osmosis concentrate; water treatment filter backwash; boiler blowdown; non-contact cooling water; water from washing whole fruits and vegetables; water from external building washing without the use of detergents or chemicals; water from washing of concrete surfaces without the use of detergents or chemicals where spills or leaks of toxic or hazardous waste has not occurred; hydrostatic testing water from existing vessels that previously contained petroleum products; and other sources that meet the numeric screening limits for industrial reuse water without secondary or advanced wastewater treatment. Page 1 of 18

2 Activities covered under the permit but not requiring registration This permit authorizes the reuse of up to 25,000 gallons per day of industrial reuse water originating from Category II industrial reuse sources without registration. Sources identified as Category II industrial reuse water must follow all permit requirements, but are not required to register with DEQ. Sources of Category II industrial reuse water have not been concentrated or degraded during industrial activities and have no added detergents or chemicals (such as but not limited to corrosion inhibitors, antifreeze compounds, and biocides), except chlorine. Category II industrial reuse water sources may include and are limited to the following: air conditioning condensate, compressor condensate, steam condensate; once-through non-contact cooling water; and hydrostatic testing water from new vessels or existing vessels that previously contained only raw water, potable water, or elemental gases. Activities not requiring registration under the permit The following activities do not require registration under this permit: The discharge of industrial reuse water to an approved sewerage system or other DEQ-permitted wastewater treatment and disposal system. The reuse of water for industrial activities or other process-related uses at the facility, such as wash water, when all industrial reuse water is captured, does not discharge to the environment, and the resulting wastewater is discharged to an approved sewerage or other DEQ-permitted wastewater treatment and disposal system. The reuse of industrial reuse water for activities inside a structure that are approved under the Oregon Plumbing Specialty Code, such as toilet and urinal flushing, when the resulting wastewater is discharged to an approved sewerage system or onsite wastewater treatment system approved under OAR Industrial discharges or reuse activities authorized under another permit. Source location Statewide Coverage and eligibility The effective date of this permit is August 1, The permit is a general permit that is issued in accordance with OAR where activities involve similar types of operations, similar types of wastes, and similar monitoring conditions. This permit applies to industrial facilities that generate industrial waters that without secondary or advanced wastewater treatment are suitable for direct reuse by seasonal irrigation, as a water source in non-residential landscape ponds, and in limited industrial, commercial, or construction uses. The facility may not reuse more than 25,000 gallons of wastewater per day for reuse. Wastewater must meet industrial reuse screening limits without secondary or advanced treatment. Source wastewater must not contain constituents that would adversely impact soils or crop growth. Source wastewater must not be contaminated by human or animal wastes. Page 2 of 18

3 The facility must connect to a sanitary sewer or other permitted wastewater treatment and disposal system. Wastewater reuse is not covered under another general permit. Any person not wishing to be covered under a general permit may apply for coverage under an individual WPCF permit. Page 3 of 18

4 Table of Contents Introduction: What is DEQ proposing? Regulatory context Permit history Permit discussion Page 4 of 18

5 Introduction: What is DEQ proposing? The Oregon Department of Environmental Quality (DEQ) is proposing to issue a new 2501 WPCF General Permit allowing the use of industrial wastewater in the environment. Industrial wastewater includes any aqueous liquid that results from any process of industrial, manufacturing, trade or business, or from the development or recovery of any natural resource. DEQ regulates the release of industrial wastewater to the environment that will or may cause pollution of waters of the state. Under this permit, DEQ sets conditions for beneficial reuse of industrial wastewater that without secondary or advanced wastewater treatment is suitable for direct reuse, based on water quality characteristics. Industrial wastewater that meets specific water quality screening levels, based on measured or expected water quality characteristics, is defined as industrial reuse water. Currently, a facility wanting to use industrial reuse water in the environment for seasonal irrigation, in a nonresidential landscape pond, or for limited industrial, commercial, or construction uses is required to obtain an individual WPCF permit. The 2501 General Permit encourages water reuse by offering a lower cost permit alternative. Only facilities generating industrial wastewater that meet numeric industrial reuse water screening limits without secondary or advanced wastewater treatment are eligible for this permit. The industrial reuse water screening limits described in the permit are primarily derived from water quality guidelines for irrigation published by land grant universities (e.g., Oregon State University) and the U.S. Environmental Protection Agency (USEPA). The industrial reuse water screening limits are not permit discharge limits, but permit eligibility requirements that may be adjusted when the general permit is renewed based on newly published guidelines or materials. Restricting reuse activities only to waters that meet these criteria ensures the protection of public health, groundwater and surface water. Limiting the irrigation of industrial reuse water only to wastewater that is suitable for long-term irrigation also ensures the continued productivity of Oregon farm land 1. Under this permit, DEQ recognizes two categories of industrial reuse water. Category I industrial reuse water includes sources of water that may have been concentrated or slightly degraded during primary use, but have no added detergents or chemicals. Category II industrial reuse water includes sources that have not been concentrated or altered and have no added detergents or chemicals. Both Category I and Category II sources are required to follow conditions in the permit. DEQ proposes to approve the registration of Category I sources based on water quality information provided with the permit application. Category II sources are not required to submit an application or register with DEQ. Although a person registered under this permit will be required to develop and maintain documentation specific to the operation of their systems, DEQ will not review this material before issuing coverage and will rely solely on water quality information. DEQ will monitor compliance of Category I sources through annual compliance reports, which will include monitoring of water quality parameters commonly associated with nuisance conditions (i.e., BOD5 and TSS), parameters that may suggest adverse effects on crops or soils (i.e., EC, ph, oil and grease), and mobile nutrients that may migrate through soil to groundwater (i.e., NO 3 -N). 1 ORS (1) The uses allowed under ORS (1)(y) and (1)(v): (a) Require a determination by the Department of Environmental Quality, in conjunction with the department s review of a license, permit or approval, that the application rates and site management practices for the land application of reclaimed water, agricultural or industrial process water or biosolids ensure continued agricultural, horticultural or silvicultural production and do not reduce the productivity of the tract. Page 5 of 18

6 Under this permit, industrial reuse water may be used in the landscape only for: (1) seasonal landscape irrigation of golf courses, cemeteries, highway medians, industrial or business campuses; (2) seasonal irrigation of agricultural crops not intended for human consumption; (3) as a source of water in nonresidential landscape ponds; (4) rock crushing, aggregate washing, mixing of concrete; (5) dust control; and (6) non-structural fire-fighting. Industrial reuse water unsuitable for reuse, produced at volumes exceeding that required for reuse, or produced during periods of the year when reuse is inappropriate must be discharged to a sanitary sewer or other DEQ-permitted wastewater treatment and disposal system. Since wastewater can be discharged to a sanitary sewer or other permitted disposal system, DEQ considers the use of industrial reuse water a beneficial reuse program, not a disposal program. Regulatory context Industrial reuse water, as defined in this permit, is a subset of industrial waste which is defined under ORS 468B.005 as any liquid, gaseous, radioactive or solid wastewater substance or a combination thereof resulting for any process of industry, manufacturing, trade or business, or from the development or recovery of any natural resources. ORS 468B.020 directs DEQ to take action necessary to prevent and control pollution of the water of the state. ORS 468B.015 establishes a state policy to prevent water pollution as well as conserve waters of the state through innovative approaches such as the reuse of water and wastes. OAR contains the conditions under which DEQ may develop general permits for certain categories of minor discharge sources or minor activities where individual NPDES or WPCF permit are not necessary to adequately protect the environment. DEQ has determined that a number of facilities in Oregon produce industrial reuse water that would be suitable for reuse under a general permit. These minor sources include, but are not limited to: reverse osmosis concentrate, non-contact cooling water, some wash waters, condensates, and hydrostatic testing water. Only facilities that produce water that meets industrial reuse water screening limits without secondary or advanced wastewater treatment are eligible for coverage under this general permit. Facilities covered under the permit will be allowed to discharge under similar conditions; monitoring requirements will be similar; and operational requirements will be similar for all facilities covered under the general permit. Since operations and monitoring will be similar for sources of industrial reuse water, a lower-cost general permit can be issued to encourage reuse activities. Permit history This is the first issuance of this general permit. DEQ has issued related general permits to sources that discharge industrial wastewater for purposes of beneficial use. Although some of these are NPDES general permits that allow both surface water discharge and land application, a number of these permits are currently expired and new registrations under these permits are not allowed. DEQ has issued and administers some industrial general permits that allow land discharge, such as: Permit Class Discharge source Expiration date 100-J NPDES Cooling water/heat pumps 7/31/ J NPDES Filter backwash 7/31/ J NPDES Boiler blowdown 7/31/ J NPDES Non-contact geothermal heat exchange 8/31/2002 Page 6 of 18

7 Permit Class Discharge source Expiration date 600 WPCF Offstream placer mining 1/31/ A WPCF Seasonal food processing and wineries, less than 25,000 10/31/2017 gallons/day 1400-B WPCF Food processors, less than 25,000 gallons/day 10/31/ B WPCF Petroleum hydrocarbon cleanups 10/31/ B WPCF Vehicle and equipment wash water 10/31/2017 Permit discussion I. COVER PAGE Sources and permitted activities. The cover page describes the sources of industrial reuse water and scope of activities allowed by this permit. This permit allows the construction, installation, and operation of a system designed to use industrial reuse water in the landscape. To be eligible for coverage under the 2501 general permit, the applicant must meet the following criteria: The maximum quantity of water generated by the permit holder for reuse may not exceed 25,000 gallons/day. This volume is consistent with the maximum volumes allowed by other similar general permits, such as the 1400-A and 1400-B. Industrial reuse water must be suitable for direct reuse without secondary or advanced wastewater treatment. Limiting reuse to sources not requiring treatment allows DEQ to issue the permit without an engineering review and approval of wastewater treatment system plans and specifications. Industrial reuse water must not contain constituents that would adversely affect soils or plant growth, such as corrosion inhibitors, antifreeze compounds, and biocides (except chlorine). Industrial reuse water must not be contaminated by human or animal wastes. This requirement excludes water sources that may contain pathogens that could be harmful to humans, pets, and livestock. Furthermore, this removes the need to disinfect water prior to use with sprinkler irrigation. The facility generating industrial reuse water must have an approved connection to a sanitary sewer or other DEQ-permitted wastewater treatment and disposal system. This provides system redundancy so that wastewater can be safely managed when reuse cannot occur. Operations covered under this permit cannot be eligible for coverage under another DEQ water quality permit. For example, a fresh-pack food processor generating less than 25,000 gallons per day would not currently be eligible for coverage under the 2501 because another general permit, 1400-A, covers land application of food processing wastewater. No discharge to state waters, including surface water or groundwater, is allowed under this permit. Application Instructions. Unless otherwise indicated, a person generating Category I industrial reuse water and seeking registration under this general permit, must do the following: 1. Complete a permit application that includes any additional required information, such as water quality data on the industrial reuse water proposed for use. Page 7 of 18

8 2. Facilities that use groundwater as a source of water for operations must complete an Oregon Water Resources Department (WRD) form (Registration for Groundwater Exemption) that qualifies the facility to reuse industrial effluent without first obtaining a water right Submit the application permit fees. Fees for this permit come from OAR , Table 70G, Other. As of 2013, the following application fees apply: New-permit application fee: $ First year annual fee: $ Total $ Send the completed permit application, any supplemental materials, and permit fees to the appropriate DEQ Regional office. Materials should be received by DEQ at least 30 days prior to the planned date of industrial water reuse. DEQ Eastern Region 700 SE Emigrant, Suite 330 Pendleton, OR P: DEQ Northwest Region 2020 SW 4th Ave, Suite 400 Portland, OR P: DEQ Western Region 750 Front St. NE, Suite 120 Salem, OR P: A person generating and reusing Category II industrial reuse water is not required to register under this permit, but may do so by filling out a permit application and paying the appropriate fees. Permit Processing. DEQ will process permits received as described below. An incomplete application will be returned to the applicant for completion. If an application is complete, but during review of the application materials, DEQ determines that additional information is required, DEQ will request additional information from the applicant. If DEQ and the applicant jointly determine that a plan review or site inspection is necessary to grant coverage under the permit, DEQ will bill the applicant the appropriate general permit activity fees found in OAR , Table H: Activity Fee Disposal system plan review $ Site inspection and evaluation $1,2611,298 If the application materials are complete and industrial reuse water quality meets the screening limits, DEQ will send acknowledgment of registration under the permit. Coverage under the permit will be granted without a DEQ inspection. However, the permit applicant is required to have and maintain accurate and current documentation on the system design, operation, and maintenance as required under Schedule D of the permit. Permit Renewal. The 2501 general permit will be valid for period of 10 years. Any person registered under the permit and wishing to continue coverage is required to renew registration by submitting an application at least 30 days prior to expiration of the permit. 2 The 1997 Legislature passed a law allowing some reuse/land application of industrial process water without the need of a water right issued by the Oregon Water Resources Department (WRD). A simple registration of this reuse is all that is required. If this reused water replaces another water source for irrigation, the reuse registration also protects the original irrigation water right from forfeiture. Page 8 of 18

9 Permit Specific Definitions. Definitions specific to the 2501 general permit are provided. For a person to qualify for coverage under the general permit, the permittee must generate industrial reuse water that is suitable for sustained agricultural irrigation without reducing site productivity. Industrial reuse water suitable for irrigation is considered suitable for other allowed beneficial purposes identified in the permit. DEQ defines two categories of industrial reuse water Category I and Category II. Both Category I and Category II industrial reuse waters must have no added detergents or chemicals that could potentially have negative effects on human health, soils, or crop growth. General categories of chemicals that must not be present in industrial reuse water include corrosion inhibitors, antifreeze compounds, and biocides (except chlorine). Residual chlorine is allowed in industrial reuse water because it is commonly found following drinking water disinfection, is used as an anti-fouling agent in some industrial processes, and is a recommended additive in drip irrigation system. Although at excessive concentrations residual chlorine 3 may adversely affect plant growth, residual chlorine dissipates with time and does not cause long-term negative impacts on soil or crop productivity. Category I industrial reuse water includes sources that may be concentrated or slightly degraded during primary use, including but not limited to: reverse osmosis concentrate; water treatment filter backwash; boiler blowdown; non-contact cooling water; water from washing whole fruits and vegetables; water from external building washing without the use of detergents or chemicals; water from washing of concrete surfaces without the use of detergents or chemicals where spills or leaks of toxic or hazardous waste has not occurred; and hydrostatic testing water from existing vessels that previously or currently contain petroleum products. Category I industrial reuse water may also come from any industrial process that contains no added detergents or chemicals, except chlorine, and meets the numeric industrial reuse water screening limits. The industrial reuse water screening limits describe water quality criteria sufficient for long-term agricultural irrigation, based on information from the following technical sources. o o o Hopkins, et al Managing Irrigation Water Quality for crop production in the Pacific Northwest. A Pacific Northwest Extension publication. PNW 597-E. U.S. Environmental Protection Agency Guidelines for Water Reuse. EPA/600/R-12/618. Vomocil and Hart Irrigation Water Quality. Oregon State University Extension Service. FG 76. The industrial reuse water screening limits are not discharge limits, but criteria for determining eligibility under this general permit. Screening limits may be adjusted upward or downward, based on technical information, when the 2501 general permit is renewed. Category I sources must submit water quality information with their permit application to demonstrate water quality meeting the screening limits. Industrial Reuse Water Screening Limits Parameter Maximum Parameter Maximum concentration concentration BOD5 10 mg/l Aluminum (Al) 5 mg/l 3 The University of California recommends a maximum limit of 5 mg/l residual chlorine in irrigation water to prevent toxic effects on plants. Harivandi, M Interpreting Turfgrass Irrigation Water Test Results. University of California Division of Agricultural and Natural Resources. Publication Page 9 of 18

10 Parameter Maximum concentration Parameter Maximum concentration TSS 10 mg/l Arsenic (As) 0.10 mg/l TDS 1280 mg/l Beryllium (Be) 0.10 mg/l Electrical conductivity 2.0 mmhos/cm Cadmium (Cd) 0.01 mg/l TDS:EC ratio Chromium (Cr) 0.1 mg/l Nitrate-nitrogen (NO 3 -N) 30 mg/l Cobalt (Co) 0.05 mg/l Chloride (Cl) 350 mg/l Copper (Cu) 0.2 mg/l Fluoride (F) 1.0 mg/l Iron (Fe) 5.0 mg/l Boron (B) 0.75 mg/l Lead (Pb) 5.0 mg/l Oil & grease 15 mg/l Lithium (Li) 2.5 mg/l Total coliform 23 MPN/100 mls Manganese (Mn) 0.2 mg/l ph S.U. Molybdenum (Mo) 0.01 mg/l Sodium Adsorption Ratio ** Nickel (Ni) 0.2 mg/l Selenium (Se) 0.02 mg/l Vanadium (V) 0.1 mg/l Zinc (Zn) 2.0 mg/l Note on low EC waters: When the EC is below 0.20 mmhos/cm, the limits for TDS, TDS:EC ratio, and SAR do not apply. ** The combination of SAR and EC must not present a high-risk of water infiltration problems as defined in the following table. Note on low EC waters. The screening limits for TDS, TDS:EC ratio, and SAR do not apply for waters where the EC is below 0.20 mmhos/cm. These waters are so poorly buffered that normal fertilization is enough acidification to neutralize any sodium bicarbonate problems that might exist and eliminate the sodium or SAR hazard. Low EC waters should not result in any long-term problems to soil productivity both East and West of the Cascades because of their purity. The exception for low EC waters is to be cautious of water infiltration problems. Low EC waters are so pure (low EC) there is little worry about leaching and what is carried to groundwater. These waters approach the purity of rainfall and would be considered great dilution water for virtually any existing alluvial groundwater we have in the state. These waters are acceptable for irrigation with the qualification that an occasional gypsum application may be needed to help with infiltration. 4 Formatted: Superscript Formatted: Superscript Formatted: Superscript Formatted: Superscript Formatted: Superscript Formatted: Font: Bold Risk of sodium causing a water infiltration problem in soil Risk of water infiltration problem Low Moderate High SAR EC of water (ds/m or mmhos/cm) 0-3 Above Below Above Below Above Below Above Below Above Below Personal communication with Don Horneck, OSU, co-author of Managing Irrigation Water Quality for crop production in the Pacific Northwest. A Pacific Northwest Extension publication. PNW 597-E. Page 10 of 18

11 Source: Table 11 of Managing Irrigation Water Quality for crop production in the Pacific Northwest (Hopkins et al., 2007). Category II industrial reuse water includes industrial water sources that have not been concentrated during industrial activities and have no added detergents or chemicals (such as but not limited to corrosion inhibitors, antifreeze compounds, and biocides), except chlorine. Category II industrial reuse water sources include air conditioner condensate, compressor condensate, steam condensate; once-through non-contact cooling water; and hydrostatic testing water from new vessels or existing vessels that previously (or currently) contain only raw water, potable water, or elemental gases. Use of industrial reuse water from Category II sources is allowed without review and approval from DEQ. Although Category II sources must follow the conditions in the permit, they are not required to submit an application requesting registration under this general permit. II. SCHEDULE A INDUSTRIAL REUSE WATER REUSE LIMITATIONS The quality of water generated from industrial activities can vary widely, depending on the source of water, how the water was used, and what changes to the water have occurred during primary use. Some types of industrial reuse waters can contain very few contaminants at low concentrations, such as condensate or non-contact cooling water, whereas others may be heavily used and contain chemicals and residues that result from the industrial primary use. Water quality can vary even when the industrial activities remain constant because of changes in the source make-up water. For example, the reverse osmosis concentrate from a facility using surface water may be of different quality than reverse osmosis concentrate where the source water is local groundwater. Although the 2501 permit allows the use of industrial wastewater that meets numeric screening criteria, additional limitations are necessary to protect Oregon s water resources due to possible variability in source water quality. 1. Water reuse limits. Specific limits on the discharge and water quality are specified, including: a. The permit allows industrial reuse water to be used only for the following specific beneficial purposes: landscape irrigation of golf courses, cemeteries, highway medians, industrial or business campuses; agricultural irrigation of crops not intended for human consumption; in landscape ponds; and in industrial and commercial uses where water is released into the environment, including rock crushing, aggregate washing, mixing concrete, dust control, and non-structural fire fighting. DEQ may approve in writing other beneficial reuse activities when the use is consistent with requirements in the permit (e.g., no discharge to surface water or groundwater) and determined to have no impact on public health or the environment. b. The permit prohibits discharges to surface waters or stormwater management structures. Any discharge to surface water requires a NPDES permit. Discharge to stormwater management structures is prohibited since these systems are typically designed to dispose of stormwater into surface water or groundwater. c. The wastewater used for reuse must not be contaminated by any human wastes or from the processing or washing of animals or animal products. This condition allows industrial reuse water to be used without disinfection and reduces the transmission of disease causing organisms to humans, pets, or other animals. d. Prior to application on the land, solid materials must be screened and removed from the industrial reuse water. This reduces the likelihood of system failure due to clogging or Page 11 of 18

12 fouling. e. The use of industrial reuse water must be documented in a water reuse plan. The contents of the plan are described in Schedule D. f. Although use of industrial reuse water is allowed only for water that meets specific screening limits, those screening limits are not discharge limits. The parameters in Table A1 are discharge limits that must be met to demonstrate ongoing compliance with the permit. These parameters have potential to affect water reuse activities. i. Five-day biochemical oxygen demand (BOD5) measures the presence of putrescible organic materials in wastewater. Water with low concentrations of BOD5 is less likely to result in nuisance odors or cause the malfunction of irrigation equipment, such as through the clogging of nozzles. The limit of 10 mg/l for BOD5 is consistent with recommendations in USEPA s 2012 Guidelines for Water Reuse for unrestricted water reuse. ii. iii. iv. Turbidity is a simple measure of the non-dissolved solids content in industrial reuse water, such as clay, silt, finely divided organic and inorganic matter, and microscopic organisms. DEQ selected turbidity as a water quality parameter rather than Total Suspended Solids because it can be rapidly measured in the field or by a small laboratory. Irrigation water with high concentrations of solids can result in the malfunction of irrigation equipment by plugging or clogging of nozzles. High turbidity waters may also represent other water quality problems that would make it unsuitable for reuse. The proposed standard of 10 NTU is less restrictive than in Class A recycled water under OAR (7)(c) (24-hour average of 2 NTU limit) or in drinking water sources where a more stringent standard is required to protect against microbial contamination of water sources. Electrical conductivity (EC) is a simple measure of the salinity of a water source and is a surrogate for Total Dissolved Solids (TDS). DEQ based the water quality limits on EC because it can be simply and rapidly measured in the field. The permit includes 2 standards for electrical conductivity, which are based on recommendations from Pacific Northwest Extension. Irrigation water with an EC of 0.75 mmhos/cm or less is considered a very low hazard to crops, soils, and groundwater. Industrial reuse water below this limit may be used without any additional restrictions for salt management. Industrial reuse water with EC values between 0.75 mmhos/cm and 2.0 mmhos/cm may be reused with a salt management plan that is described in the water reuse plan. Irrigation of industrial reuse water with elevated salt concentrations typically requires careful management to protect both crops and groundwater. The maximum allowable limit for EC is 2.0 mmhos/cm. Industrial wastewater with concentrations above 2.0 mmhos/cm may not be reused. Oil and grease represents a broad category of compounds that are soluble in an organic solvent. Elevated concentrations of oil and grease may interfere with the operation of irrigation systems and may be visible as films or sheens in landscape ponds. Application of oil and grease to soils may result in a reduction in water infiltration rates due to plugging or sealing of soil pores. The permit limit of 15 mg/l oil and grease maintains consistency with similar permits, such as the 1700-B washwater permit. v. ph impacts soil and water chemistry, the effectiveness of nutrients, and overall crop Page 12 of 18

13 vi. production or plant growth. The Oregon State University Extension recommends irrigation water have a ph between 6.5 and 8.4. The slightly wider limits proposed in the 2501 permit have been used in other water quality permits. Nitrate-nitrogen (NO 3 -N) is the most common and mobile form of inorganic nitrogen in oxidized waters. Excess nitrogen applied to plants can cause high vegetative growth and may make plants more susceptible to insects, pathogens, and frost damage. Excess nitrogen in surface waters can cause algal blooms and eutrophication. Excessive concentrations of nitrate-nitrogen in drinking waters can result in adverse health effects, particularly in infants. The maximum allowable limit of nitrate-nitrogen in drinking water sources in 10 mg/l. The permit includes 2 standards for nitrate-nitrogen. Industrial reuse water containing nitrate-nitrogen at concentrations of 5 mg/l or less may be used without restriction. Industrial reuse water containing nitrate-nitrogen at concentrations between 5 mg/l and 30 mg/l may be used with a nutrient management plan that is described in the water reuse plan. The nutrient management plan must manage nitrate-nitrogen concentrations by accounting for removal by plant uptake. Industrial wastewater with concentrations greater than 30 mg/l may not be reused. 2. Irrigation site selection. Applying excessive industrial reuse water, irrigating industrial reuse water on poorly selected sites, or irrigating industrial reuse water at inappropriate times can cause public health or environmental impacts. However, when used on a well-selected site, applied at a volume and rate that approximately equals use by plants, and managed appropriately, industrial reuse water can be used while protecting public health and the environment. Schedule D, Condition 2 lists requirements for irrigation site selection and evaluation. The site selection requirements are intended to provide assurance that industrial reuse water does not cause adverse impacts on public health or the environment. a. Irrigation sites must be located on stable geologic formations that are not subject to excessive ponding, erosion, or runoff at the time of irrigation. Excess water applied to unstable landscapes, such as slumps or landslides, can further destabilize the landscape and result in structural failure of the underlying soil or increase erosion. Similarly, industrial reuse water is prohibited on sites subject to seasonal flooding or excessive ponding. b. Industrial reuse water cannot be applied to slopes in excess of 45 percent, due to the risk of runoff and destabilizing the landscape. c. The permit prohibits the release of industrial reuse water unless there is a minimum of 4-feet depth to groundwater. This separation distance is intended to provide assurance that any industrial reuse water moving below the plant rooting zone receives adequate soil treatment prior to entering groundwater. Although soil treatment can vary substantially based on individual site characteristics, the separation distance combined with the other industrial reuse water irrigation management requirements will minimize the movement of contaminants into groundwater. d. Knowledge of site soil and vegetation is necessary for proper design and operation of an industrial reuse water irrigation system. The soil and vegetation in the irrigation area must have sufficient capacity to accommodate the volume and rate of industrial reuse water discharged. The soil and vegetation on a specific site will determine the amount of industrial reuse water that can be successfully applied without the water ponding, running offsite, or discharging to groundwater. Although not required by DEQ, permit applicants may find the use of landscape professionals useful when evaluating irrigation site suitability and Page 13 of 18

14 developing an effective irrigation plan. Soil texture can affect water infiltration rates. Heavy clay soils tend to absorb water slowly whereas sandy soils infiltrate water quickly. As a result, irrigation sites located on clay dominated soils may require irrigation to be delivered over a larger area or at a slower rate. Very sandy soils can infiltrate water rapidly and care must be taken to avoid high application rates that can result in industrial reuse water moving beyond the root zone and into groundwater. Table 1. Approximate area needed to infiltrate a gallon of water without surfacing or runoff. From Table 16A-2, Design Criteria of Six Typical Soils, California Plumbing Code Section 16A. Soil Texture Approx. area in square feet needed to infiltrate 1 gallon of water Coarse sand or gravel 0.2 Fine sand 0.25 Sandy loam 0.4 Sandy clay 0.6 Clay with considerable sand or gravel 0.9 Clay with very little sand or gravel 60 Various resources are available to assist in determining the water needs of vegetation, such as nurseries, landscape architects, and printed materials such as Sunset Western Garden. The Regional Water Providers Consortium (RWPC) for the Portland area recommends irrigating lawns with approximately 1 inch of water per week during the summer. For example, 100 square feet of turf grass would require approximately 62 gallons of water per week. Water usage by other landscape plants will vary. The RWPC uses the following guidelines for adjusting water use: Shrubs: 50% of the Weekly Watering Number Perennials: 50% of the Weekly Watering Number Vegetables: 75% of the Weekly Watering Number (new starts may require more water) Trees: Newly planted trees need regular watering for up to the first couple of years, while established trees may need a deep soak or two in summer. e. To protect groundwater and prevent the discharge of industrial reuse water to surface water or adjacent properties, specific setbacks to sensitive features are specified in the permit. These setbacks are based on setbacks DEQ requires in similar water reuse programs in Oregon. 3. Site management practices. Site management practices are required to ensure that use of industrial reuse water occurs without adverse human health or environmental impacts. a. Industrial reuse water must not be discharged to frozen or saturated soils because of the limited ability of the soil to accommodate the added volume of water. This increases the risk of industrial reuse water surfacing and moving off-site. b. Irrigation may only occur when evapotranspiration (ET) exceeds natural precipitation. This requirement is intended to limit industrial reuse water irrigation to periods when plants require supplemental irrigation water. The period when ET exceeds precipitation will vary Page 14 of 18

15 spatially and temporally in the state. Because of climate conditions, seasonal irrigation of industrial reuse water may be limited to only a few months in the Willamette Valley and coastal areas. More arid areas of the state, such as southwest or eastern Oregon generally receive less precipitation and require more supplemental water. However, the growing season in some areas may be limited by temperature. Irrigation needs also will vary from year to year. In years with long, wet springs, irrigation may not be required in western Oregon until June, whereas in drier years, supplemental irrigation may be necessary as early as April or May (Figure 1). Since irrigation needs are variable, the individual permit holder must determine the appropriate times to use industrial reuse water for irrigation purposes and to comply with permit conditions. As a general operating principal, industrial reuse water should be used at times when supplemental irrigation water would normally be used. Figure 1. Evapotranspiration (ETOS) and precipitation (PP) for 3 locations in Oregon in 2010 and one location in both 2009 and The units of the y-axis in all charts are inches. When ETOS is higher than PP, irrigation is allowed. c. When irrigation occurs in urban areas adjacent to hard surfaces, such as sidewalks or roadways, the irrigation system must be designed and operated to avoid runoff of irrigation water from hard surfaces. This may include design and operational measures such as using directional spray nozzles or installing drip irrigation systems. d. Industrial reuse water may not run off the irrigation site or discharge to subsurface drainage tile. e. The use of industrial reuse water cannot create objectionable odors, fly and mosquito breeding, or other nuisance conditions. Although industrial reuse water must be low in organic materials, malodors and other nuisance conditions, such as the attraction of rats, birds, flies, etc., may suggest that oxygen in the water has been depleted due to the rapid growth of bacteria, resulting in anoxic or septic conditions. f. Signs are required when industrial reuse water is used for irrigation and in landscape ponds to Page 15 of 18

16 notify the public that nonpotable is used and is not safe for drinking. This management practice informs the public and limits human exposure to industrial reuse water. g. When industrial reuse water is used in a landscape pond, the pond must be lined with an impermeable membrane or other suitable barrier to prevent the infiltration of industrial reuse water into the subsurface. This management practices protects groundwater. h. Although industrial reuse water is of a quality suited for long-term irrigation, the permit holder must take care to avoid the creation of aerosols that could impact public health. For example, the permittee could implement a management practice to use spray irrigation only during hours with lower public exposure. 4. Connection to wastewater disposal systems. The permittee must have and maintain a connection to a wastewater disposal system, such as a sewer connection or other DEQ-permitted wastewater treatment and disposal system. The wastewater connection provides a mechanism for wastewater disposal when industrial reuse water cannot be reused in a manner that protects public health and the environment. For example, if the water quality exceeds the limits in Table A1, industrial reuse water must be directed to the disposal system. Under some conditions, industrial reuse water may not be safely reused without possible impacts to the environment, such as during extended wet weather events, when soils are frozen or saturated, or when supplemental irrigation water is not needed to maintain plant growth. When conditions are unsuitable for reuse, industrial reuse water must be directed to a wastewater disposal system. During system maintenance or repair events when the reuse system may be unavailable, industrial reuse water should be diverted to the wastewater disposal system, thereby protecting public health and the environment without interrupting routine industrial activities. 5. Prohibited uses. Industrial reuse water may not be used for drinking, personal hygiene bathing, showering, cooking, dishwashing, and maintaining oral hygiene. These prohibitions are based on OAR (97): Human consumption means water used for drinking, personal hygiene bathing, showering, cooking, dishwashing, and maintaining oral hygiene. 6. Property lines crossed. In general, use of industrial reuse water is limited to the property on which it was generated. However, if the permit holder has a written agreement with another property owner, industrial reuse water may be used offsite. If industrial reuse water crosses property lines, the owner or owners of both properties must follow the requirements of the permit. III. SCHEDULE B - MONITORING REQUIREMENTS The 2501 WPCF General Permit requires the permittee to monitor and report on the water quantity, water quality and operations of the industrial reuse water system. The monitoring and reporting requirements apply to both Category I and Category II industrial reuse water as described below. 1. On a daily basis when industrial reuse water is used, the permittee must monitor the total volume of water delivered for reuse. When irrigating, the permittee must monitor and record the total weekly quantity of water irrigated in inches/acre. Verification of flow rates (e.g., flow meter calibration or verification of pump rate) must occur annually when reuse starts. Category I industrial reuse water sources must also collect and analyze representative water samples on a monthly and/or annual basis. Grab samples must be analyzed for BOD5, EC, turbidity, oil and grease, ph, and nitrate-nitrogen. The permit allows ph to be measured using ph test strips (i.e., ph paper) when the resolution is ±0.5 S.U. Page 16 of 18

17 2. A water reuse annual report must be submitted to DEQ by January 31 describing operations during the previous calendar year. The report must be submitted on a form and format approved by DEQ. A simple reporting form will be available on DEQ s website. Currently, DEQ requires hard copies of annual reports be submitted, but may provide opportunities for electronic submissions in the future. Two copies must be submitted to DEQ: one copy must be sent to the DEQ regional office; a second copy must be sent to the DEQ Water Reuse Program coordinator. The annual report must contain the following information: a. An annual summary of the quantity and uses of industrial reuse water; b. When industrial reuse water is used for irrigation, the report must provide a weekly summary of the quantity of water used for irrigation; c. The results of any required water quality monitoring; d. A brief description of any changes to industrial activities that would affect industrial reuse water quality. Changes may include, but are not limited to, changes in primary source water, changes in processing, or changes in processing equipment; e. When industrial reuse water is used for irrigation, a summary of any changes to irrigation areas, crops, or factors that would affect irrigation requirements; f. When used for irrigation, a description of any changes to irrigation area, vegetation, or other factors that would affect water reuse; and g. A description of any failures of the reuse system and corrective actions taken. IV. SCHEDULE D SPECIAL CONDITIONS Schedule D includes special conditions on required documentation, system alterations, and permit revocation. 1. Water reuse plan. Although the permit applicant is not required to submit documentation to DEQ for review and approval to obtain coverage under the general permit, the permittee is required to have system documentation complete and available for inspection by DEQ on request. The water reuse plan provides details on the water reuse system design and operations. The plan describes how the permittee will meet the permit requirements. 2. Irrigation site evaluation. When industrial reuse water is used for irrigation, the permittee must maintain a record on the irrigation site evaluation. 3. Construction standards. Specific requirements for the construction of an industrial reuse water system include: a. Direct connections between potable water supplies and the industrial reuse water reuse system are not allowed except as approved by a local water authority. For example, if a landscape irrigation system will supply both potable and nonpotable water, the permit holder must obtain necessary approval for a cross-connection prevention device (e.g., backflow preventer, air-gap) from the local water provider. b. All industrial reuse water delivery systems must be appropriately labelled to identify it as containing nonpotable water. Nonpotable water may be identified using purple pipe or labelled with text identifying the water as unsafe to drink. Page 17 of 18

18 c. Irrigation components, such as sprinkler heads, must be identified as using nonpotable water by using purple-colored fixtures. Use of clear signage at the reuse area is an acceptable alternative to purple irrigation fixtures. d. The reuse system must be constructed and installed as required by other state or local authorities. 4. The permittee must notify DEQ of any changes to the industrial reuse water system that would affect permit status or make it ineligible for coverage under the general permit. 5. DEQ may revoke the general permit, based on specific circumstances, and require the permittee to apply for an individual permit. V. SCHEDULE F GENERAL CONDITIONS, WPCF INDUSTRIAL FACILITIES Schedule F includes general conditions that apply to all WPCF general permits for industrial facilities. When conditions in Schedules A, B, and D are redundant or more stringent than those in the general conditions of Schedule F, the provisions in Schedules A, B, and D in the permit supersede the Schedule F general conditions. Page 18 of 18