5 Colo. Code Regs. § 1002-84.26
The provisions of sections 25-8-202, 25-8-205(1), and 25-8-205.8, C.R.S., provide the specific statutory authority for adoption of amendments to this regulation. The Commission also adopted, in compliance with section 24-4-203(4), C.R.S., the following statement of basis and purpose.
BASIS AND PURPOSE
On April 30, 2018, House Bill 18-1069 was enacted, essentially codifying Regulation 84 provisions such as category standards 1 through 3 and the pre-existing allowed uses of reclaimed water for categories 1 through 3. The primary purpose of House Bill (HB) 18-1069 was to add toilet and urinal flushing in multifamily residential and nonresidential structures as category 3 uses for reclaimed domestic wastewater. The Bill becomes effective on August 8, 2018.
Prior to the enactment of HB 18-1069, the Commission noticed a regulatory proposal by Denver Water to modify Regulation #84 to add toilet and urinal flushing ("fixture"), indoor cannabis irrigation, and adopt new standards for reclaimed water treatment for certain types of treatment systems. Denver Water subsequently withdrew its proposal to add indoor cannabis irrigation to Regulation #84 from consideration. Denver Water and the Division also submitted a motion for consideration of a joint proposal to modify Regulation #84.
On August 6, 2018, the Commission held a rulemaking hearing to consider the joint proposal presented by Denver Water and the Division, for modification of Regulation#84. Following the rulemaking hearing, the Commission updated Regulation #84 to add fixture flushing consistent with the specific definitions and requirements contained in HB 18-1069. The Commission also adopted new definitions and treatment requirements for two types of reclaimed water treatment systems: "centralized reclaimed water treatment systems" (centralized systems) and "localized reclaimed water treatment systems" (localized systems) to further encourage the reuse of reclaimed domestic wastewater and ensure protection of public health. In addition, the Commission adopted a statutory definition of "point of compliance"; described treatment, filtration, and disinfection requirements for centralized systems producing category 3 reclaimed water for toilet flushing; adopted a log reduction treatment approach for localized treatment systems with monitoring requirements for localized systems to ensure that these systems are operating correctly; and additional cross-connection control requirements for uses of reclaimed water used for indoor non-potable uses.
The Commission modified the definition of point of compliance to conform with the new statutory definition of point of compliance adopted in HB 18-1069. The definition provides that the point of compliance "means, except as provided in subsection (1)(f)(II) of this section, a point, as identified by the person that treats the water in the reclaimed domestic wastewater treatment process or the reclaimed domestic wastewater transportation process, that occurs after all treatment has been completed but before dilution and blending of the water has occurred." Subsection (1)(f)(II) provides that "If reclaimed domestic wastewater is used for indoor nonpotable uses within a building where plumbing fixtures are accessible by the general public, 'point of compliance' is at the location where water is delivered to the occupied premises."
Subsection (1)(f)(I) and (II) in HB 18-1069 refer to the categories of reclaimed water (categories 1 through 3) and the standards that must be met regarding total suspended solids, turbidity and E. coli. The Commission construed subsection (1)(f)(II) as applying to the disinfection residual. Disinfection residual is a best management practice used to prevent regrowth of waterborne pathogens within indoor plumbing systems. It is not practical from an operational, economic or implementation standpoint to continuously test for E. coli at buildings using reclaimed water indoors, but meeting the disinfection residual requirements at the building is practical and will protect public health. The treatment facility supplying the reclaimed water will meet the statutory and regulatory standards after treatment and before dilution and blending.
To protect against potential regrowth of opportunistic pathogens and increases in turbidity in the underground distribution system prior to entering a building, Regulation 84.9(A)(9)(a-c) requires that users follow a best management practice of monitoring for disinfectant residual and/or another approved disinfection methods for indoor uses of reclaimed water, which monitoring may occur at the distal end of the plumbing system. These treatment approaches are intended to prevent growth of opportunistic pathogens, such as legionella from proliferating within building plumbing pipes and fixtures. Meeting the residual requirements at the distal end of the plumbing system will protect public health from opportunistic pathogens within buildings as an additional protective measure.
With regard to the point of compliance for localized systems, the point of compliance will be a point, as identified by the treater, in the reclaimed domestic wastewater treatment process or the reclaimed domestic wastewater transportation process, that occurs after all treatment has been completed but before dilution and blending of the water has occurred. The Commission finds that in most cases localized systems will be located at or near the tap of the building, parcel, or district where domestic wastewater is being treated and used. This means that it is less likely that the disinfection residual in reclaimed water produced from localized systems will dissipate due to the shorter travel time for reclaimed water from localized systems to the point of use. In addition, for localized systems there is continuous monitoring of the process system to confirm log removal targets are being met. For these reasons, the point of compliance for disinfection residual for localized systems located near the site of use may also be at the point identified by the treater that occurs after all treatment has been completed but before dilution and blending of the water has occurred.
The Commission adopted definitions for centralized and localized reclaimed water treatment systems; defined treatment, filtration, and disinfection requirements for centralized systems producing Category 3 reclaimed water for fixture flushing; and adopted a new log reduction treatment approach and control monitoring framework for localized systems to track whether the treatment control system is operating to meet E. coli and turbidity requirements.
Centralized Systems
Regulation 84 previously did not define "reclaimed water treatment systems" or "centralized reclaimed water treatment systems". Rather, reclaimed water treatment systems were encompassed by the definition of "treater" and the definition of "reclaimed water". The adoption of the definition of "centralized reclaimed water treatment systems" is intended to encompass the reclaimed water treatment systems that would have been defined as a "treater" or "reclaimed water" in the original, 2000 version of Regulation #84.
To distinguish centralized systems from localized systems, the Commission adopted a definition of "centralized reclaimed water treatment systems" that define such systems as receiving domestic wastewater from a diverse service area for treatment to produce reclaimed water for beneficial use where the service area has meaningful inputs from industrial or other diluting sources. The phrase "meaningful inputs or other diluting sources" relates to the consistent watering down of waterborne pathogens in the untreated source water consistent with large municipal-like collection systems.
The Commission adopted filtration standards for reclaimed water produced from centralized systems for toilet flushing based upon a multi-barrier approach. California Title 22 establishes a framework for multiple barrier framework supported by a microbial risk assessment ("MRA"). The Commission found the California treatment recommendations to be too limiting for the expansion of reuse in Colorado and has allowed a wider range of filtration techniques that provide equivalent microbial protections appropriate for indoor reuse application. The Commission concluded that there should be a defined list of technologies allowed for Category 3 reclaimed water used for toilet flushing because of the higher risk of public exposure to reclaimed water from unintended cross-connections. All types of filtration are not adequate for pathogen reduction for indoor uses of reclaimed water. However, the Commission has listed accepted filtration technologies which include any filter approved per 5 CCR 1002-11 and the ability to challenge test and demonstrate reclaimed water specific filtration techniques.
The Commission agreed with the California Title 22 minimum requirement of 5 log virus treatment for indoor uses of reclaimed water. The Commission found that the virus inactivation tables published by the EPA are appropriate when chemical disinfection is used. If UV disinfection is employed, virus disinfection should be measured against Hepatitis A for chemical disinfection or 40 mJ/cm2 for ultraviolet light disinfection.
The Commission adopted a new section 84.8 , which describes the filtration and disinfection requirements for centralized reclaimed water being used for fixture flushing. The Commission also adopted definitions of filter technologies, including bag filter and cartridge filter, conventional filtration, direct filtration, and membrane filtration. To add clarity regarding the meaning of treatment standards, the Commission adopted definitions for secondary treatment and treatment technique requirements.
The Commission directed the Division to hold a stakeholder process with reclaimed water users, treaters and other interested parties to consider whether similar or alternative treatment techniques should be applied to other categories of reclaimed water and authorized uses.
Definition of Localized Systems
Localized reclaimed water treatment systems are defined by several characteristics that distinguish them from centralized systems. Specifically, localized systems:
* receive and treat domestic wastewater that does not have meaningful inputs from industrial and other diluting sources.
* are located relatively close to the location where wastewater is generated meaning that there is little travel time for wastewater, and less time for pathogen die off to occur.
These factors contribute to more concentrated raw wastewater, and therefore higher pathogen loads in the domestic wastewater treated by localized systems.
To address the distinct characteristics of localized systems, the Commission defined "localized reclaimed water treatment systems" as systems that receive and treat domestic wastewater from a single building, multiple buildings within a single property or area bounded by dedicated streets or ways, or a district designated by a City or County for treatment to produce reclaimed water for beneficial use where the source water does not have meaningful inputs from industrial or other diluting sources. This definition is intended to reflect that localized systems collect wastewater from a more concentrated and defined area as compared to centralized systems.
The Commission adopted a new rule providing that NOAs for use of reclaimed water from localized systems may include requirements for limitations on contributions from non-domestic sources as necessary to prevent pass through, interference or impacts on public health or the environment from those sources. The Commission also adopted a requirement that the user plan to comply for localized systems identify the percentage contributions from each wastewater input to the localized system and the location of the input as well as any limitations on contributions from non-domestic sources.
Treatment Based Framework for Localized Systems
The Commission also adopted a treatment-based framework for localized systems. The framework for localized systems is structured around treatment performance criteria. A treatment-based approach for localized systems helps ensure that systems are designed properly, that public health will be protected despite less frequent sampling and higher degrees of automation, and helps streamline permitting for a variety of small treatment systems throughout the state.
The treatment-based approach utilizes treatment performance-based logarithmic ("log") reduction targets for the treatment of pathogens in localized systems to meet various risk thresholds. The Commission directs the division to develop a policy (localized system design criteria) that will define treatment credits for various unit processes or alternate demonstration/testing option while discharging to the sewer. Treatment-based approach allows for an automated approach through continuous monitoring, and avoids the need to perform frequent grab samples for E. coli, a cost burden that provides little benefit for assessing how localized systems perform in real time.
The Commission considered two different risk levels for localized system log removal targets, and concluded that due to the high risk of unintended cross-connections between potable and reclaimed water plumbing, 10-4 risk level (1 infection per 10,000 individuals annually) is appropriate for localized systems treating reclaimed water for Category 3 uses. The Commission concluded that 10-2 risk level (1 infection per 100 individually annually) is appropriate for localized systems treating reclaimed water only for Category 2 uses due to the low risk of exposure from unintended cross connections. The Commission also approved 10-2 risk level for enteric viruses only for localized systems treating reclaimed water only for Category 1 uses, again due to the low risk of exposure from unintended cross connections and restricted access limits for on-site uses.
Because localized systems generally lack access to on-site laboratories and more limited staffing, the Commission adopted requirements for continuous treatment monitoring of unit processes with high frequency (on the order of minutes between sample analysis and recording) to ensure those processes are operating to specification. The Commission found that localized systems should be continuously monitored to ensure that treatment is performing as expected.
The Commission decided that localized reclaimed water system treaters should not be required to continuously monitor for E. coli because localized systems that treat to the log removal targets adopted by the Commission will meet the E. coli limits in section 84.7 , so long as the localized system process controls are operated and maintained in accordance with their design as verified by the monitoring of the unit processes. The Commission found that the continuous treatment monitoring process, as well as the initial field verification, will verify that the log removal targets are being met, and that the localized system is meeting the required log removal targets and therefore in compliance with the E.coli standard for Categories 1, 2 and 3 reclaimed water. For these reasons, the Commission determined it is not necessary for localized systems to consistently monitor for E.coli. Acceptable surrogate parameters for localized systems listed in Table C of Section 84.10 , if operating properly and continuously monitored and verified, will result in the log reduction targets in Table B in 84.10 and meet or exceed the standards provided in Categories 1, 2 and 3 of reclaimed water. The Commission approved several surrogates in Table C for monitoring the operation of system process control, and directed the Division to develop a policy approving other acceptable surrogates for continuous monitoring of localized systems.
The type of continuous monitoring should be selected on a system-by-system basis. During the field verification and commissioning study, the treater must confirm that the treatment technologies have been installed in accordance with the approved design and are operating per their specifications. The monitoring approach will be included in the operations and monitoring plan.
The Commission currently intends for localized systems, like centralized systems, to be approved under the site location and design approval process in Regulation 5 CCR 1002-22, and encourages the Division to hold a stakeholder process to consider modifications to Regulation 22 to consider any changes that should be made to address localized systems.
The Commission also adopted a requirement providing that a user include as part of its user plan to comply an affidavit attesting that the user employs a certified operator or an agreement showing that a certified operator has been retained. The Commission determined that this is necessary to ensure that the user is capable of operating the localized system and able to comply with Regulation #84. The report must be certified by the user.
To protect water provider water rights, the Commission adopted language requiring that letters of intent include an affirmation that the proposed installation of a localized system is allowed by the water service provider where the localized system is located in the service area of a water provider.
Risk of Exposure to Reclaimed Water from Fixture Flushing
The Commission approved reclaimed water for fixture flushing in multi-family and non-residential structures. The primary risk of exposure to reclaimed water when used for toilet flushing is from unintended cross-connections with potable water plumbing. To minimize risk of exposure to reclaimed water from unintended cross-connections with potable water plumbing, the Commission adopted additional disinfection requirements and cross-connection control requirements.
Disinfection Requirement for Toilet and Urinal Flushing Using Centralized and Localized System Reclaimed Water
A BMP of a minimum of 0.2 mg/L for free or 0.5 mg/L for monchloramines of chemical disinfectant is required within the reclaimed water of premise plumbing of buildings approved for indoor toilet and urinal flushing. This BMP mitigates the potential for Legionella exposure associated with indoor uses. The Division may approve alternative disinfection approaches that have equivalent protection against premise plumbing pathogens. The Commission directs the Division to hold a stakeholder process to determine whether similar or different disinfection requirements should be applied to other categories of indoor uses for reclaimed water. The commission also discussed the importance of ensuring a maximum amount of chlorine residual is not exceeded for indoor uses, especially in light of the potential for chlorine boosting to be occurring. The commission felt that the maximum levels required by the International Plumbing Code address the issue, however the commission expects that during the development of future changes to this regulation, the division and stakeholders will consider whether the addition of a maximum chlorine residual level is necessary in this regulation.
Cross Connection Control Requirements for Toilet Flushing
The Commission included a requirement providing that only licensed plumbers may perform maintenance or make modifications to plumbing within structures that use reclaimed water for toilet flushing. Structures using reclaimed water for toilet flushing must maintain signage providing notice that modifications may be performed only by licensed plumbers.
The Commission determined that structures that use reclaimed water indoors must have an approved cross connection control device or method to prevent contamination of potable water distribution systems also serving the structures. In addition, the owner of the structure using reclaimed water for toilet or urinal flushing must conduct testing to detect uncontrolled cross connections by a certified cross-connection control technician prior to initial operation of the system and at intervals thereafter as mandated in the notice of authorization. Additionally, where reclaimed water is used indoors and could be cross connected with other non-potable water supplies, devices must be installed at service connections to protect the higher quality water from accidental contamination from the lower quality water source.
The user must maintain a current diagram of the structure's potable and reclaimed water plumbing. The public should not have access to the plumbing within structures that use reclaimed water indoors. Structures using reclaimed water for fixture flushing must be in compliance with the State Plumbing Code promulgated by the Colorado State Plumbing Board.
The Commission adopted a rule clarifying that use of reclaimed water for indoor fixture flushing is prohibited if after treatment reclaimed water is stored in an outdoor open-air storage structure.
Additional Requirements for Fixture Flushing
To protect public health and ensure a continuity of water supply, the Commission determined that users of reclaimed water for toilet flushing must maintain a backup potable water supply connection in the event of upsets or a failure of a localized reclaimed water treatment system or centralized reclaimed water treatment system.
The Commission also adopted a requirement that users have a protocol to switch to potable water and redirect reclaimed water to the sanitary sewer in the event that the reclaimed water is not in compliance with Regulation #84.
The Commission finds that its modifications to Regulation #84 are consistent with the intent of HB 18-1069, and presents no increase in the potential risk to human health or the environment. The Commission also found that its modifications further facilitate the safe and efficient use of Colorado's limited water resources.
The addition of the use of reclaimed water for toilet and urinal flushing as a Category 3 Standard is authorized by HB 18-1069. This bill authorizes reclaimed domestic wastewater to be used for indoor toilet and urinal flushing if the reclaimed water meets the Category 3 Standard. HB18-1069, Section 3(2)(c)(IV); § 25-8-205.7(2)(c)(IV), C.R.S.
The Commission further found that the bifurcated designation of reclaimed water treatment systems is also within the authority granted by HB18-1069. The bill amends the previous statutory definition of "reclaimed domestic wastewater". HB18-1069, Section 1; § 25-8-103 (17.5), C.R.S. However, the bill does not define the reclaimed water treatment systems that would produce reclaimed domestic wastewater. Control regulations may be promulgated to describe requirements and standards that will encourage the reuse of reclaimed domestic wastewater. See HB-1069, Section 2(1)(f); § 25-8-205(1)(f), C.R.S. Centralized systems are the default reclaimed water systems that were encompassed by the prior Regulation 84 definition of "treater". The Commission found that the addition of "localized systems" as another type of treatment system that would also produce reclaimed domestic wastewater would encourage the use of reclaimed domestic wastewater, consistent with the declaration in HB 18-1069.
The other substantive changes to the regulation describe treatment, filtration, disinfection, monitoring, and other technical requirements. The Commission determined that the addition of these requirements are consistent with the authority granted by HB18-1069. The bill requires wastewater to "at a minimum" receive secondary treatment with filtration and disinfection in order to meet a Category 3 Standard. HB18-1069, Section 3, subsection (1)(c)(I); § 25-8-205.7(1)(c)(I), C.R.S. However, the bill does not define "secondary treatment," "filtration," or "disinfection". It also does not define or describe the monitoring or technical requirements necessary to ensure reclaimed water meets the requirements for each Category Standard. Control regulations may be promulgated to describe requirements and standards that will protect public health and encourage public use. See HB-1069, Section 2(1)(f); § 25-8-205(1)(f), C.R.S. The Commission finds that the requirements adopted herein concerning treatment, filtration, disinfection, monitoring, and other technical requirements strike a proper balance between the objectives of protecting public health and encouraging the reuse of domestic wastewater.
PARTIES TO THE RULEMAKING
5 CCR 1002-84.26