5 Colo. Code Regs. § 1003-2-100.5

Current through Register Vol. 47, No. 11, June 10, 2024
Section 5 CCR 1003-2-100.5 - DOMESTIC WASTEWATER TREATMENT FACILITY CLASSIFICATION
100.5.1 Domestic wastewater treatment facilities shall be classified in accordance with the following four classes: Class D, Class C, Class B, or Class A. Class A is the highest level of classification and Class D is the lowest level of classification. The Division may make changes in classification in accordance with the needs created by particular complexities of any specific domestic wastewater treatment facility based on consideration of facility specific factors, including, but not limited to:
(a) design features or other characteristics that make the facility more difficult to operate than usual;
(b) facility design flow;
(c) the character and volume of wastes to be treated;
(d) the facility's design being approved under the Department's variance procedure;
(e) a waste unusually difficult to treat;
(f) flow conditions, use classifications and/or water quality standards assigned to the waters receiving the treated effluent that require an unusually high degree of plant operational control in order to meet permit conditions; or
(g) combinations of such conditions or circumstances.
100.5.2 Table - Criteria for Domestic Wastewater Treatment Facility Classes A, B, C, and D

Treatment Type1

Plant Design Hydraulic Capacity (in MGD)

Below 0.5

0.5-1.00

1.01-2.00

2.01-4.00

Above 4.00

Preliminary Treatment

Coarse Solids Reduction (e.g., comminution, macerator, grinder)

D

D

C

C

B

Screening with manually cleaned bar screen

Screening with mechanically cleaned screen, fine screen,

C

C

B

B

A

Flow equalization,

Grit removal,

Plant pumping of main flow

Primary Treatment

Sedimentation basin (pond, septic tank)

D

C

C

C

B

Primary Clarifier

Oil and grease processing

C

C

B

B

A

Dissolved air flotation (DAF)

Chemically Enhanced Primary Clarification for settling improvements (coagulation, flocculation)

B

B

B

B

A

Active Primary Clarification (e.g., anaerobic generation of volatile fatty acids)

B

B

A

A

A

Secondary Treatment

[Purpose to treat BOD, TSS to secondary limits.]

Recirculating sand filtration

D

C

C

C

C

Waste stabilization ponds, including aerated and non- aerated types

D

C

C

B

B

Trickling filter

Rotating biological contactor

C

C

B

B

A

Treatment wetland (surface flow, subsurface flow) or subsurface submerged bioreactor for BOD and/or suspended solids

C

C

B

B

A

Extended aeration process sequencing batch reactors (SBR) designed to operate in the extended aeration loading range.

C

B

B

B

A

Activated sludge (e.g., conventional, complete mix, contact stabilization, extended aeration, step-feed, oxidation ditch, non-extended aeration SBR)

Fixed biofilm reactor (e.g., fixed activated sludge treatment or FAST)

Submerged granular media biofilm

Moving bed biofilm reactor (MBBR)

B

B

B

B

A

Integrated biofilm and activated sludge (IFAS)

Membrane bioreactor (MBR)

Membrane aerated biofilm reactor (MABR)

Anaerobic reactors (e.g., upflow sludge blanket, baffled reactor, multiple compartment reactors, sequencing batch reactor, fluidized bed reactor, membrane bioreactor, filter)

B

B

A

A

A

Pure oxygen activated sludge

A

A

A

A

A

Secondary Clarification

Secondary clarifiers (biofilm)

C

C

B

B

A

Secondary clarifiers (suspended growth)

B

B

B

B

A

Dissolved air flotation (DAF)

Ballasted enhanced settling

B

B

A

A

A

Advanced Treatment

[Purpose to treat beyond secondary limits both within secondary treatment units and/or physically separate processes after secondary treatment.]

Biological or Chemical/Biological Advanced Waste Treatment

Suspended growth (e.g., MLE, A2O, Bardenpho, membrane bioreactor (MBR), aerobic granular sludge, advanced biological algae treatment, etc.)

B

B

A

A

A

Biofilm (e.g., trickling filter, rotating biological contactor, fixed biofilm reactors (FAST), moving bed biofilm reactors (MBBR), submerged granular media biofilm, integrated biofilm and activated sludge (IFAS), biologically active carbon, membrane aerated biofilm reactor (MABR), denitrification filters, etc.)

Anaerobic reactors (e.g., upflow sludge blanket, baffled reactor, multiple compartment reactors, sequencing batch reactor, fluidized bed reactor, membrane bioreactor, filter)

Phosphorus removal (e.g., biological, chemical, etc.). Not including struvite recovery - see solids handling.

Treatment wetland (e.g., surface flow, subsurface flow) or subsurface submerged bioreactor (e.g., for nitrogen, phosphorus, metals)

Deammonification

A

A

A

A

A

Pure oxygen activated sludge

Chemical/Physical Advanced Waste Treatment

[For unit treatment process and not solely

an adjusting condition for an earlier

biological process (e.g., pH, alkalinity,

carbon feed).]

Air stripping

C

C

B

B

A

Adsorptive media (granular activated carbon, Zeolite, organoclay)

B

B

A

A

A

Low voltage electro-coagulation / electro-flocculation

Ion exchange

Electro-chemical (e.g., electrodialysis, electrolysis, electro-oxidation, high voltage electro-coagulation/flocculation)

Industrial operator

Industrial operator

Industrial operator

Industrial operator

Industrial operator

Advanced oxidation and/or oxidation/reduction (e.g., hydrogen peroxide + UV, metal ox/reduction recovery)

Chemical precipitation (e.g., metal hydroxide precipitation, metal sulfide precipitation). Not including struvite recovery - see solids handling.

Filtration

Cloth filter, cartridge bag/filter

C

B

A

A

A

Slow sand filtration

Upflow sand filtration (no chemical addition)

Coagulation, flocculation, sedimentation

B

B

A

A

A

Media filtration (rapid sand, dual media)

Upflow sand filtration (with chemical addition)

Membrane filtration (microfiltration, ultrafiltration)

Diatomaceous earth (DE)

Membrane filtration (nanofiltration)

A

A

A

A

A

Reverse osmosis

Disinfection / Inactivation

Free chlorine, contact basin (e.g., premade liquid solution, solid tablets, hypochlorination with liquid solution onsite generation from solid)

D

C

C

B

B

Ultraviolet radiation (UV)

C

B

B

B

A

Peracetic acid, contact basin

Free chlorine, contact basin (gaseous)

C

C

B

A

A

Advanced oxidation, electro processes for disinfection

B

B

A

A

A

Ozonation, contact basin

A

A

A

A

A

Dechlorination

Solid materials (e.g., puck, granular)

D

C

C

B

B

Liquid materials

C

C

B

B

A

Gaseous materials

C

C

B

A

A

Chemical Addition

[Includes adjusting condition such as pH, alkalinity,

carbon feed, etc. and chemicals for other unit processes.]

Solid materials

C

C

B

B

A

Liquid non-flammable materials

C

C

B

B

A

Gaseous materials

C

C

B

A

A

Flammable materials

B

B

A

A

A

Effluent Discharge

Effluent discharge to receiving stream or groundwater

D

C

C

B

B

Effluent discharge to reclaimed water storage/distribution system for outdoor uses or drinking water treatment plant for further treatment

C

B

B

B

A

Effluent discharge to reclaimed water distribution system with indoor uses. (If reclaimed treatment facility classified as wastewater facility, use Table 100.4.2 also. If classified in 100.6.1(c) as drinking water facility, use only Table 100.4.2.)

WWBif WW,

also DW facility class required

WWBif WW,

also DW facility class required

WWA if WW,

also DW facility class required

WWA if WW,

also DW facility class required

WWA if WW,

also DW facility class required

Effluent discharge to potable water distribution system (Use Table 100.4.2 also.)

WWA

also DW facility class required

WWA

also DW facility class required

WWA

also DW facility class required

WWA

also DW facility class required

WWA

also DW facility class required

Solids Handlinq

Thickening / Conditioning (e.g., gravity, DAF, plate settlers, drum thickeners, volute thickener, centrifuge thickening, polymer addition)

Dewatering (e.g., lagoon, drying bed, mechanical such as belt, filter press, polymer addition) Aerobic digestion

Solids composting

C

B

B

B

A

Thermal hydrolysis (e.g., pre-digestion)

Stabilization / digestion (e.g., anaerobic sludge lagoon, autothermal or autoheated thermophilic aerobic digestion (ATAD), anaerobic digestion (single, multi-stage))

Nutrient recovery through precipitation (e.g., struvite recovery)

Centrifuge for dewatering

Solids reduction (e.g., incineration, wet oxidation)

B

B

A

A

A

Note: 1. The treatment processes are listed as examples and are not all inclusive but are representative and the division will categorize other technologies consistent with this list and classify facilities based on the similar technologies.

100.5.3 The classification of any domestic wastewater treatment facility may be changed at the discretion of the Division based on changes in any condition or circumstance since the last classification determination.
100.5.4 Any domestic wastewater treatment facility that utilizes a combination of two or more of the treatment processes described in section 100.5.2 shall be classified in accordance with the highest level of treatment process utilized.

5 CCR 1003-2-100.5

37 CR 18, September 25, 2014, effective 10/30/2014
38 CR 14, July 25, 2015, effective 8/30/2015
39 CR 01, January 10, 2016, effective 1/30/2016
39 CR 24, December 25, 2016, effective 1/30/2017
40 CR 14, July 25, 2017, effective 8/31/2017
41 CR 20, October 25, 2018, effective 3/1/2019
41 CR 24, December 25, 2018, effective 3/1/2019
42 CR 24, December 25, 2019, effective 1/14/2020
43 CR 21, November 10, 2020, effective 11/30/2020
44 CR 05, March 10, 2021, effective 3/31/2021
44 CR 09, May 10, 2021, effective 5/30/2021
44 CR 20, October 25, 2021, effective 11/30/2021