5 Colo. Code Regs. § 1002-84.16
Current through Register Vol. 47, No. 20, October 25, 2024
Section 5 CCR 1002-84.16 - ADDITIONAL REQUIREMENTS FOR LOCALIZED RECLAIMED WATER TREATMENT SYSTEMS(A) Reclaimed water treated by localized reclaimed water treatment systems must comply with the standards and requirements in this regulation (sections 84.1 through 84.15) and in this section 84.16.(B)Field Verification and Commissioning Report and Inspection. For localized reclaimed water treatment systems, prior to supplying reclaimed water for use, the Treater must verify that the system is operational and meets reliability requirements of the log removal targets in section 84.16 below. Following completion of field verification and commissioning, the Treater shall provide the Division a field verification and commissioning report and an operations and monitoring plan. The field verification and commissioning report will confirm that the treatment system has been installed and is operating in accordance with the approved design criteria in section 84.16 below. The operations and monitoring plan will define the frequency and locations for monitoring, data storage, and reporting. The Division may conduct an inspection of the localized reclaimed water treatment system to confirm that the unit treatment processes have been installed in conformance with the approved design and are in operation in accordance with operations and monitoring plan.(C) Division Review and Issuance of Treater Authorization. The Division will review the field verification and commissioning report and operations and monitoring plan for localized reclaimed water treatment systems in addition to the Treater Application and conduct the requirements as described in 84.6(B).(D) The Treater must properly operate and maintain all required treatment systems when producing reclaimed water in accordance with this regulation, the Treater Authorization and the site location and design approvals. In addition to the factors to be considered and approved by the Division under Regulation #22, localized reclaimed water treatment systems are subject to the following additional design requirements for treatment.(1) The Treater must properly operate a multi-barrier treatment approach using filtration and disinfection following secondary treatment while producing reclaimed water that reliably achieves all of the logarithmic ("log") reduction targets for pathogens set forth in Table B below. If a Treater conducts its own microbial risk assessment, the Treater may request approval from the Division to use alternative log reduction targets based upon the Treater's microbial risk assessment.(a) Reclaimed water produced from localized systems for Category 1 uses must meet the design requirements based on a microbial risk assessment using a risk target no less stringent than 10-2 infections per person per year only for Enteric Viruses as set forth in Table B below.(b) Reclaimed water produced from localized systems for Category 2 uses must meet the design requirements based on a microbial risk assessment using a risk target no less stringent than 10-2 infections per person per year as set forth in Table B below.(c) Reclaimed water produced from localized systems for Category 3 uses must meet the design requirements based on a microbial risk assessment using a risk target no less stringent than 10-4 infections per person per year as set forth in Table B below. Table C: Localized System Log Removal Targets for Treatment Design
Enteric Viruses | Parasitic Protozoa | Enteric Bacteria |
Log10 Reduction Target (10-2) Category 1 | 6.0 | - | - |
Log10 Reduction Target (10-2) Category 2 | 6.0 | 5.0 | 4.0 |
Log10 Reduction Target (10-4) Category 3 | 8.5 | 7.0 | 6.0 |
(2) The Division will develop policy defining credits for the log reduction of pathogens through various treatment processes.(3) The localized system design requirements will be based on the assumption that the wastewater does not receive meaningful inputs from industrial or other diluting sources.(E) Localized System Monitoring Requirements:(1) Reclaimed water produced from localized systems must meet the standards for the category of reclaimed water in section 84.7 for the approved use. Compliance with the standards in section 84.7 shall be verified by the monitoring requirements in section 84.16(C)(2) and (3) below.(2) Localized reclaimed water treatment systems must be continuously monitored for appropriate process control parameters to demonstrate that systems designed to comply with pathogenic microorganism control are functioning properly. The choice of the type of continuous monitoring technologies to be utilized will be tailored for an individual system and will be included in an operations and monitoring plan. Examples of acceptable forms of continuous monitoring for localized system process control are identified in Table C below: Table D: Acceptable Surrogate Parameters for Localized Systems
Surrogate Parameter | Surrogate Monitoring Point | Purpose |
Chlorine residual | Post-chlorination at a representative location for treatment | Confirm control of opportunistic pathogens |
Continuous turbidity or particle size distribution | Post-filtration at a representative location for treatment | Confirm operation of filtration system; can be an indicator of pathogen breakthrough |
Pressure decay test1 | Membrane filtration unit | Measures membrane integrity |
Electrical conductivity or tracer spike test; total organic carbon or UV absorbance (254 nanometers) | Reverse osmosis or nanofiltration unit | Can be related to pathogen breakthrough |
Continuous color, ultraviolet light absorbance (UVA) or transmittance (UVT), and/or pH | Prior to disinfection or ozonation | Can indicate conditions that inhibit pathogen removal in disinfection or ozonation steps |
Residual ozone, or oxidation-reduction potential | Ozonated water | Can be correlated to pathogen removal |
Continuous ultraviolet (UV) intensity | UV-treated water | Confirm sufficient dose of UV for pathogen inactivation |
1This test can be used and monitored on a frequency to be determined by the Treater and approved by the Division.
(3) The Division shall adopt a policy identifying other acceptable monitoring technologies for localized system treatment processes and means to approve additional monitoring techniques. The operations and monitoring plan shall include a tailored quality assurance plan specific to the continuous monitoring equipment in place. The quality assurance plan may include analysis of periodic grab samples for additional quality assurance of data collected via continuous monitoring, with parameters measured being consistent with those measured via continuous monitoring.(F) The Treater must return any recycled spent filter backwash water, thickener supernatant, or liquids from the dewatering process to a location within the treatment process that is before the filtration technology or an alternative Department-approved location.(1) For conventional or direct filtration, the location of return must be prior to the coagulant feed location.(2) For all other filtration technologies, the location of return must be prior to the filtration process and approved by the Division.(G) Localized reclaimed water treatment systems shall include a flow meter on the localized reclaimed water treatment system and a flow meter on the potable make-up water pipeline to the distribution system.(H) Localized reclaimed water treatment systems must be equipped with features that result in a controlled and non-hazardous automatic shutdown of the process in the event of a malfunction. Localized reclaimed water treatment systems must maintain overflow connections to an approved and permitted domestic wastewater treatment works to allow for disposal of off-specification treated reclaimed water or to allow disposal of untreated wastewater during maintenance of the treatment system. Overflow connections will include an approved cross connection control device or method.(I) 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.(J) Additional Implementation Requirements for Localized Systems (1) Protocol to switch to potable water and redirect reclaimed water to the sanitary sewer system no later than 12 hours after receipt of the results of any water quality test sample that does not meet the water quality requirements of the Treater Authorization or indication of a process malfunction based on continuous monitoring. Systems required to redirect reclaimed water to the sanitary sewer may resume normal operation after the Division receives a letter explaining why the performance was compromised and what actions were taken to prevent it from reoccurring, and three (3) consecutive days of data showing compliance, and the Division issues an approval to resume operations.(2) An affidavit by the User attesting to the employment of a certified operator or a service contract with a certified operator, who meets the requirements of Regulation 100.(3) An enforceable legal agreement defining the roles and responsibilities of the User and Treater.(4) If required, the User shall identify the percentage contributions from each wastewater input to the localized system and the location of the input, and any 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.41 CR 21, November 10, 2018, effective 11/30/201842 CR 23, December 10, 2019, effective 1/14/202043 CR 17, September 10, 2020, effective 9/30/202045 CR 14, July 25, 2022, effective 8/14/2022