crediting on-site wastewater treatment systems in the...
TRANSCRIPT
Crediting On-Site Wastewater Treatment Systems in the Bay
Watershed
Photo Credit: The Animal Foundation in Las Vegas Nevada, treats its wastewater
by a Tidal Flow Wetland Living Machine® system.
Photo Credit: Vegetative Tertiary Filter by WetlandsPacific Corporation in
Vancouver, British Columbia
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• December 2: Meeting the Chesapeake Bay Restoration
Requirements for Industrial Sites in MD
• December 4: Verification Simplified! Urban BMP
Verification for Local Governments
• December 11: The Best Urban BMP in the Bay Award!
Speaker Info
Victor D'Amato, PE, Tetra Tech, [email protected]
Ning Zhou, Virginia Polytechnic Institute, [email protected]
Cecilia Lane, Chesapeake Stormwater Network, [email protected]
Poll Question #1
How many people are watching with you today?
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• > 10 people
Poll Question #2
Tell us a little about yourselves…who are you representing today?
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Poll Question #3
What proportion of homes in Maryland rely on septic systems for treatment of their wastewater?
• 0%
• 10%
• 20%
• 30%
• 40%
Today’s Agenda
• Septics: The Silent Source
• Crediting for On-site Wastewater Treatment Systems
• Update on Nutrient Attenuation Panel
• FAQs
• Webcast Resources
The Process
• Outlined in the WQGIT BMP Review Protocol (WQGIT, 2014)
• BMP Expert Panel reviews existing research set of recommendations
• Recommendations used to derive methods and/or protocols to derive nutrient removal rates for the proposed BMP
BMP EXPERT PANEL
WASTEWATER WORKGROUP
WATER QUALITY
GIT
WATERSHED TECHNICAL
WORKGROUP
Septics: The Silent Source?
• 4 kg TN/person/year
• Average household size: 2.5 ppl
• = 10 kg TN/household/year
• = 22 lbs TN/household/yr
How Urban Land Cover is Represented in the
Current Version of CBWM
Impervious Cover Pervious Cover
Acres in Watershed 1 1,269,030 3,398,732 Average TN Load 2 15.5 lbs/ac/yr 12.4 lbs/ac/yr 1 Acres as reported in most recent CBWM version 5.3.2 2 Average values, as reported in Tetra Tech 2014a and ESC EP, 2014 (construction sites), although actual values are regionally variable
How Septic Load is Calculated in the Current
Version of CBWM At the edge of drain field:
Septic N Load (lbs/yr) = Population *8.91586 (lbs/person, yr) *BMP Rate
At the edge of stream:
Septic N Load (lbs/yr) = Population *8.91586 *BMP Rate* Pass-through rate
Delivered N Loads to the Bay (lbs/yr)
= Population *8.91586 *BMP Rate* Pass-through rate *River Delivery Rate
Pass-through rate (%) = 1- Attenuation Rate (%)
How Septic Load is Calculated in the Current
Version of CBWM Septic N pass-through rate – Percent of septic N loads that
pass through the ground soil and reach the edge of stream
Current septic N pass-through rate used in the model is 40% for everywhere in the Bay watershed except MD.
MDE guidance on Septic N Load Delivery Rates
• 80% for septic systems within the Critical Area (1,000 feet from tidal surface water)
• 50% for septic systems outside the Critical Area and within 1,000 feet of non-tidal waters
• 30% for all other septic systems
Agriculture 44.08%
Urban Runoff 16.73%
Wastewater 16.20%
CSO 0.58%
Septic 3.59%
Other 18.81%
2013 TN Delivered Loads by Sources
5.16
8.42 8.33 8.75
6.19
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
1985 2009 2011 2013 2025
TN D
eliv
ere
d L
oad
s (m
il lb
s/yr
) Septic TN Delivered Loads
(mil lbs/yr)
87.59 (0%)
50.59 (42%) 43.01
(51%) 39.47 (55%)
37.95 (57%)
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
1985 2009 2011 2013 2025
TN D
eliv
ere
d L
oad
s (m
il lb
s/yr
) Wastewater TN Delivered Loads (mil lbs/yr)
and Reduction (%) from 1985
Sector
2009 Load
Target Load % Reduction Needed to Meet Target
Million pounds per year
Forest 7.00 7.00 0
Atm. Deposition 0.69 0.69 0
Wastewater 13.9 10.94 21%
Urban and Suburban Runoff
5.88 4.42 25%
Agricultural 18.05 13.59 25%
Septics 4.01 -0- 39%
TOTAL 49.53 2.46 21%
Source: US EPA Chesapeake Bay Program, 2010
Total Nitrogen Loads By Sector in the Maryland Portion of the Chesapeake Bay Watershed
Outline
OWTS BMP Expert Panel charge and membership
Baseline loadings from on-site systems
BMP definitions and qualifying conditions
Future research and management recommendations
OWTS Attenuation Expert Panel charge and membership
Progress and status
Frequently asked questions
Cost considerations
OWTS Panel Charge
Initially convened in January 2012
Review available science on the nitrogen removal performance of treatment practices
Provide concise definitions and percent reductions for nitrogen load reduction practices
Provide a definition for each treatment practice and the qualifying conditions under which credits can be received
Only address TN reduction in treatment technologies, not in the soil between edge-of-system and edge-of-stream (“attenuation”)
List of Panelists
Panelist Organization
Jim Anderson University of Minnesota
Eric Aschenbach Virginia Department of Health
Jason Baumgartner Delaware Department of Natural Resources and Environmental Control
Derrick Caruthers Delaware Department of Natural Resources and Environmental Control
Marcia Degen Virginia Department of Health
Kitt Farrell-Poe University of Arizona
Joshua Flatley Maryland Department of the Environment
Robert Goo U.S. Environmental Protection Agency
Rick Hertges West Virginia Health and Human Services
Mike Hoover North Carolina State University
Joyce Hudson U.S. Environmental Protection Agency
Randy Miles University of Missouri
Jeff Moeller Water Environment Research Foundation
Dave Montali West Virginia Department of Environmental Protection
Sushama Pradhan North Carolina State University
Jay Prager Maryland Department of the Environment
Other Authors and Contributors
Robert Adler – EPA Region 1
Jay Conta – Virginia Tech
Rich Piluk – Anne Arundel County Health Department
Staff/Contractor Support
Ning Zhou – Virginia Tech
Jeremy Hanson – Chesapeake Research Consortium
Victor D’Amato, Jim Kreissl, Mark Sievers – Tetra Tech
Baseline Load – Current Model
4 kg TN/person/year at edge-of-drainfield
• Assumed flow of 75 gpcpd
• TN concentration of 39 mg/L in septic tank effluent (STE)
60 percent attenuation between drainfield and edge-of-stream
Three BMPs
• Connection to central sewer (100 percent reduction from on-site sector)
• 50 percent denitrification system (50 percent reduction)
• Routine septic tank pump-out (5 percent reduction)
Baseline Load Recommendations
5 kg TN/person/year in raw wastewater and STE
• Assumed flow of 60 gpcpd
• TN concentration of 60 mg/L in septic tank effluent (STE)
4 kg TN/person/year at edge-of-drainfield
• 20 percent reduction in drainfield, average
No attenuation recommendation
Baseline Load Recommendations
Baseline System
Systems with BMPs
Exsitu BMP
• BMP efficiency assessed at end of process prior to soil application
• Reduction based on baseline effluent TN of 5 kg/person/year
Insitu BMP
• Reduction based on TN removal beyond baseline 20 percent reduction or 4 kg/person/year at edge-of-drainfield
Combined Insitu and Exsitu BMPs
• Reduction based on TN of 4 kg/person/year at edge-of-drainfield
• Assume consistent TN reduction across the soil treatment system, regardless of exsitu effluent characteristics
Best Management Practices
Exsitu (or pretreatment) system components
NSF Standard 40 Class I secondary systems
Intermittent (single-pass) media filters
Constructed wetlands (vegetated submerged beds)
Recirculating media filters (RMFs)
Anne Arundel County Integrated Fixed-Film Activated Sludge (IFAS)
Proprietary ex situ treatment systems
Insitu (soil treatment) system components
Shallow-placed, pressure-dosed dispersal
Elevated sand mounds
Permeable reactive barriers
Residential System with BMP
System with Exsitu BMP
Best Management Practices
Performance of recommended BMPs is well-supported by science and verifiable data • Ongoing sampling and analysis for each system is not recommended
for verification
Recommendations intended to complement existing state regulations and policies • Design and management criteria, beyond minimum standards
• Large/non-residential systems
Recognition that biological nitrogen removal performance can be variable • Encourage minimum USEPA Level 2 management model (operators,
permits)
• Suggestions for overarching management activities to promote effective BNR
Best Management Practices
Proprietary BMPs • Developed, marketed, and constructed by a manufacturer
• Manufacturer responsibility for system design, installation, and ongoing management
• Standardized design and construction and little variability between the same model
• Recommend two-step credit assignment protocol: provisional testing (e.g., NSF Standard 245) followed by third-party field testing
• TN reduction credit of 50 percent, unless managed according to min. EPA Level 3
Nonproprietary BMPs • Designed on case-by-case basis for each site using nonspecific and
readily available materials and mechanical equipment
• Local design and material variations common
• Two-step protocol for new systems goes through WWTWG
BMP Report Outline/TOC
Exsitu BMP Summary
Best Management Practice Qualifying Conditions
Ex Situ Reduction
Credit1
Septic tank (baseline practice)
N/A 0
NSF 40 Class I Equivalent Secondary Systems
Certified as Class I under NSF International Standard 40 or equivalent (e.g., CAN/BNQ 3680-600, CEN Standard 12566-3)
Design, installation, and operation in accordance with manufacturer recommendations and state or local regulation
20%
Intermittent media filters Timer-based flow equalization with 12–24 doses/day
2’ depth media ES = 0.5-1.0 mm; UC ≤ 4.0; < 0.5% passing #200 sieve
HLR ≤ 2 gpd/sf
OLR ≤ 5 lb BOD/1000 sf
Uniform, pressurized distribution ≤ 6 sf/orifice
20%
Constructed wetlands 2’ depth media ES = 40–80 mm inlet/outlet; ES = 20–30 mm treatment zone
OLR ≤ 1.2 lb BOD5/1000 sf-day; SA ≥ 54 sf/PE
Length ≥ 50 ft
Outlet structure for variable flooding depth
6” top layer of planting media
20%
RMF Timer-based flow equalization with 24–48 doses/d
2’ depth media
Sand media: ES = 1.0–5.0 mm; UC ≤ 2.5; < 0.5% passing #200 sieve; HLR ≤ 5 gpd/sf; OLR ≤ 5 lb BOD/1000 sf
Gravel media: ES = 5.0–20 mm; UC ≤ 2.5; < 0.5% passing #200 sieve; HLR ≤ 15 gpd/sf; OLR ≤ 15 lb BOD/1000 sf
Uniform, pressurized distribution ≤ 6 sf/orifice
Device capable of recirculating 3–5 times forward flow back to anoxic zone
50%
Anne Arundel County IFAS
2-day HRT anoxic chamber
1-day HRT aerobic chamber with ≥ 600 sf surface area fixed-film media
Aeration device capable of maintaining 3.0 mg/L DO
Device capable of recirculating ≥ 3 times forward flow back to anoxic zone
Alarm for aeration device fault
50%
Proprietary treatment systems
NSF Standard 245 certification
Technology-specific
Percent removal based on qualifying third-party testing
≥ 50%
Exsitu BMPs
Exsitu BMP Summary
Best Management Practice Qualifying Conditions
Ex Situ Reduction
Credit1
Septic tank (baseline practice)
N/A 0
NSF 40 Class I Equivalent Secondary Systems
Certified as Class I under NSF International Standard 40 or equivalent (e.g., CAN/BNQ 3680-600, CEN Standard 12566-3)
Design, installation, and operation in accordance with manufacturer recommendations and state or local regulation
20%
Intermittent media filters Timer-based flow equalization with 12–24 doses/day
2’ depth media ES = 0.5-1.0 mm; UC ≤ 4.0; < 0.5% passing #200 sieve
HLR ≤ 2 gpd/sf
OLR ≤ 5 lb BOD/1000 sf
Uniform, pressurized distribution ≤ 6 sf/orifice
20%
Constructed wetlands 2’ depth media ES = 40–80 mm inlet/outlet; ES = 20–30 mm treatment zone
OLR ≤ 1.2 lb BOD5/1000 sf-day; SA ≥ 54 sf/PE
Length ≥ 50 ft
Outlet structure for variable flooding depth
6” top layer of planting media
20%
RMF Timer-based flow equalization with 24–48 doses/d
2’ depth media
Sand media: ES = 1.0–5.0 mm; UC ≤ 2.5; < 0.5% passing #200 sieve; HLR ≤ 5 gpd/sf; OLR ≤ 5 lb BOD/1000 sf
Gravel media: ES = 5.0–20 mm; UC ≤ 2.5; < 0.5% passing #200 sieve; HLR ≤ 15 gpd/sf; OLR ≤ 15 lb BOD/1000 sf
Uniform, pressurized distribution ≤ 6 sf/orifice
Device capable of recirculating 3–5 times forward flow back to anoxic zone
50%
Anne Arundel County IFAS
2-day HRT anoxic chamber
1-day HRT aerobic chamber with ≥ 600 sf surface area fixed-film media
Aeration device capable of maintaining 3.0 mg/L DO
Device capable of recirculating ≥ 3 times forward flow back to anoxic zone
Alarm for aeration device fault
50%
Proprietary treatment systems
NSF Standard 245 certification
Technology-specific
Percent removal based on qualifying third-party testing
≥ 50%
Best Management Practice Qualifying Conditions
Ex Situ Reduction
Credit1
Septic tank (baseline practice)
N/A 0
NSF 40 Class I Equivalent Secondary Systems
Certified as Class I under NSF International Standard 40 or equivalent (e.g., CAN/BNQ 3680-600, CEN Standard 12566-3)
Design, installation, and operation in accordance with manufacturer recommendations and state or local regulation
20%
Intermittent media filters Timer-based flow equalization with 12–24 doses/day
2’ depth media ES = 0.5-1.0 mm; UC ≤ 4.0; < 0.5% passing #200 sieve
HLR ≤ 2 gpd/sf
OLR ≤ 5 lb BOD/1000 sf
Uniform, pressurized distribution ≤ 6 sf/orifice
20%
Constructed wetlands 2’ depth media ES = 40–80 mm inlet/outlet; ES = 20–30 mm treatment zone
OLR ≤ 1.2 lb BOD5/1000 sf-day; SA ≥ 54 sf/PE
Length ≥ 50 ft
Outlet structure for variable flooding depth
6” top layer of planting media
20%
RMF Timer-based flow equalization with 24–48 doses/d
2’ depth media
Sand media: ES = 1.0–5.0 mm; UC ≤ 2.5; < 0.5% passing #200 sieve; HLR ≤ 5 gpd/sf; OLR ≤ 5 lb BOD/1000 sf
Gravel media: ES = 5.0–20 mm; UC ≤ 2.5; < 0.5% passing #200 sieve; HLR ≤ 15 gpd/sf; OLR ≤ 15 lb BOD/1000 sf
Uniform, pressurized distribution ≤ 6 sf/orifice
Device capable of recirculating 3–5 times forward flow back to anoxic zone
50%
Anne Arundel County IFAS
2-day HRT anoxic chamber
1-day HRT aerobic chamber with ≥ 600 sf surface area fixed-film media
Aeration device capable of maintaining 3.0 mg/L DO
Device capable of recirculating ≥ 3 times forward flow back to anoxic zone
Alarm for aeration device fault
50%
Proprietary treatment systems
NSF Standard 245 certification
Technology-specific
Percent removal based on qualifying third-party testing
≥ 50%
Exsitu BMPs
Exsitu BMPs
Insitu BMP Summary
Best Management Practice Qualifying Conditions
In Situ Reduction
Credit1
Conventional system (baseline practice)
N/A 20%
Shallow-placed, pressure-dosed dispersal
Drip or LPD within 12” of grade in A or A/B horizon
Credit not provided for sand or loamy sand soils
Lines placed on contour
Drip requires: prefiltration system, automatic flush cycle, flow equalization, air release valves
LPD requires: working pressure head of 2–5’, dosing volume of 7–10 times distribution system piping, lateral flushing provisions, max flow variation of 10% for each lateral
50%
Elevated sand mounds
Installation within intact A or A/B horizon
Credit not provided for sand or loamy sand surface soils under mound
Scarify surface of soil under mound
Uniform, pressurized distribution ≤ 6 sf/orifice
1–2’ layer of sand: ASTM C33; ≤ 20% by weight > 2 mm; D10 = 0.15 to 0.3 mm; UC = 4 to 6
Max. top of sand ALR = 1 gpd/sf for STE, 2 gpd/sf for secondary
6–12” loamy surface layer
50%
Permeable reactive barriers
Site-specific Case-by-case
Insitu BMPs
41
Combined Exsitu and Insitu BMPs
In Situ Practice
Ex Situ Practice Conventional
Baseline Shallow, Pressure
Dosed Elevated Mound
Septic tank baseline 4.0 kg/p/yr (0%) 2.5 kg/p/yr (38%) 2.5 kg/p/yr (38%)
NSF 40 Class I Secondary Systems 3.2 kg/p/yr (20%) 2.0 kg/p/yr (50%) 2.0 kg/p/yr (50%)
Intermittent Media Filter 3.2 kg/p/yr (20%) 2.0 kg/p/yr (50%) 2.0 kg/p/yr (50%)
Vegetated Submerged Bed 3.2 kg/p/yr (20%) 2.0 kg/p/yr (50%) 2.0 kg/p/yr (50%)
Anne Arundel Co. IFAS 2.0 kg/p/yr (50%) 1.25 kg/p/yr (69%) 1.25 kg/p/yr (69%)
Recirculating Media Filter 2.0 kg/p/yr (50%) 1.25 kg/p/yr (69%) 1.25 kg/p/yr (69%)
Research and Management Recommendations
Alkalinity control
• Critical for effective nitrification (50 mg/L recommended in final effluent)
• R&D for simple, inexpensive alkalinity control would help optimize TN removal and could justify higher credits in future
BMP sampling
• Not recommended to be mandatory for verification
• However, widespread BMP implementation offers opportunity for data collection
Data sharing and reciprocity
• EPA-OWM offered to facilitate
• Also addressed at July 2013 SORA/NEHA conference
Variable baseline and BMP performance by soil type
• Consider including soil type as predictor of TN reduction performance
• Defer to future attenuation expert panel
Attenuation Panel Charge
This is what we
care about!
Attenuation
Attenuation Panel Charge
Review science on how to factor attenuation of N and P
into TMDL onsite system load estimates.
● Can model can be improved by using attenuation rates that vary?
● Is 100% removal of total phosphorus (TP) from onsite wastewater system effluents warranted?
● Recommend a methodology and specific attenuation rates to be used in different contexts.
Also:
● Document data needs.
● Recommend procedures for reporting, tracking and verifying.
● Critically analyze any unintended consequences.
Member Classification
Name Organization Alternates Member Type Org. Type
Jason Baumgartner Delaware Derek Caruthers, Jack Hayes Voting ChesBay State Government
Jay Prager Maryland DEP Barry Glotfelty Voting ChesBay State Government
Tom Boekeloo New York DEP Voting ChesBay State Government
John Diehl PA DEP Nick Hong Voting ChesBay State Government
Marcia Degen Virginia DOH Eric Aschenbach, Jay Conta Voting ChesBay State Government
Dave Montali West Virginia Rick Hertges Voting ChesBay State Government
Robert Siegrist Colorado School of Mines Voting Academia
Michael O'Driscoll East Carolina University Charlie Humphreys Voting Academia
David Lindbo North Carolina State U Voting Academia
Jim Anderson University of Minnesota Voting Academia
Randy Miles University of Missouri Voting Academia
Carol Ptacek University of Waterloo Voting Academia
John Galbraith Virginia Tech Voting Academia
Durrelle Scott Virginia Tech Voting Academia
Kang Xia Virginia Tech Voting Academia
Eberhard Roeder Florida DOH Elke Ursin Voting State Government (other)
A.J. Maupin Idaho DEQ Voting State Government (other)
Sushama Pradhan NC Onsite Water Protection Steven Berkowitz Voting State Government (other)
Joyce Hudson US EPA - OWM Maureen Tooke Voting EPA
Robert Goo US EPA - OWOW Voting EPA
Rob Adler US EPA - Region 1 Voting EPA
Paul Finnell USDA Voting Federal Government (other)
Judy Denver USGS Voting Federal Government (other)
George Heufelder Barnstable County DHE Voting County Government (other)
David Sample Virginia Tech Advisory Academia, representative from the STAC
Rich Piluk Anne Arundel Co. HD Advisory ChesBay Local Government
Jeff Moeller WERF Guest Research Foundation
Lewis Linker Bay Program Office Advisory EPA, representative from the CBP modeling team
Ning Zhou Bay Program Office Advisory CBPO, representative from the WWTWG
David Wood Bay Program Office Supporting CBPO
Victor D'Amato Tetra Tech Supporting Consultant
Jim Kreissl Tetra Tech Supporting Consultant
Appointing a Chair
Responsibilities:
● Leader of panel
● Point of contact with Coordinator
● Help Coordinate
– Assign responsibilities
– Manage comment process
– Brief WWTWG
– Respond to comments
– Resolve issues
Multiple nominees (most declined)
Chair: Dr. David Lindbo
● NC State University Soil Science/Exension
● Specialty: Soil-Environment Relations
Activities to Date
Administration and orientation
White paper development/background discussions
Literature collection/dissemination
Six conference calls
● Lew Linker presentation on Bay model
● Bob Siegrist presentation on STUMOD
Developed draft report outline
● Use to assign/synthesize/summarize literature
● Start writing based on calls, etc.
Attenuation Panel Considerations/Issues
Variable as a function of soil characteristics
● Soil type
● Soil depth
● Soil geochemistry (redox conditions, labile carbon)
Variable as a function of topography
● Setback distance
● Riparian areas or wetlands in flow path
Variable as a function of effluent characteristics
● STE versus pre-treated
Nitrogen and phosphorus or just nitrogen?
White Paper - Attenuation Accounting Methodologies
Watershed Constant: single, average attenuation rate is used across the entire Bay watershed.
Subwatershed Constant: Different average attenuation rates assigned to different subwatersheds.
Spatially Variable: Attenuation rates assigned to different areas based on their spatial characteristics.
Site-Specific: Attenuation rates customized for individual systems, based on characteristics and location.
September 17 Conference Call
Maryland Maps – from Paul Finnell (USDA)
Report Outline
Introduction
● Historical approach
● Maryland (and others) approach
● Proposed geomorphic approach
● Challenges
Methods
● Describe weight of evidence approach
● Literature
● Modeling
● Hydrogeomorphology
Results and Discussion
● Coastal Plain
● Piedmont
● Ridge and Valley
● Appalachian Highlands
Conclusions and Recommendations
Future Activities
Refine draft outline (Nov-Dec)
Assign/review literature (Nov-Feb)
Internal draft report (Feb-Apr)
Draft report to WWTWG (Apr-May)
Additional review/revision
Frequently Asked Questions
If shallow, pressure dosed drainfields provide 50% reduction of TN, then why are they only credited with a 38% reduction.
● Shallow pressure dosed drainfields reduce STE from 5.0 kg/c/yr to 2.5 kg/c/yr (50% reduction).
● However, the edge of drainfield TN of 2.5 kg/c/yr needs to be compared with that for the baseline system – a conventional drainfield which achieves a 20% reduction to 4.0 kg/c/yr.
● 2.5 kg/c/yr I 4.0 kg/c/yr = 38%
Frequently Asked Questions
Will BMP performance vary based on soil or other site-specific characteristics?
● Possibly. This is mainly going to be addressed by the attenuation panel.
● We did exclude sands and loamy sands from receiving insitu BMP credits, but otherwise, no variability based on receiving soil type.
● Soil treatment unit performance may vary based on the quality of the effluent being applied.
Frequently Asked Questions
What about malfunctioning systems or large/non-residential systems?
● These have not be separately/specifically addressed by the panels.
● Current Bay model already factors malfunctions into “average” performance assumptions.
● Large/non-residential systems are somewhat covered by the existing model methodology that uses census tract population to estimate loads.
● Improving identification and improvement of malfunctioning systems may provide significant water quality benefits.
Frequently Asked Questions
“How much does it cost?”
System Installation Electrical O&M 60-yr PV LCC
Septic tank $3,500
($2,800-4,200)
0 $90
($70-110)
$6,700
($5,400-8,000)
Activated Sludge $9,000
($8,000-10,000)
$100
($80-120)
$560
($450-670)
$33,500
($27,000-40,000)
RMF $16,500
($13,000-20,000)
$10
($8-12)
$750
($600-900)
$43,500
($35,000-52,000)
Conventional $5,750
($4,600-6,900)
0 $300
($200-400)
$16,500
($15,000-18,000)
LPP $11,500
($9,000-14,000)
$25
($20-30)
$670
($540-800)
$36,000
($29,000-43,000)
Drip $10,150
($8,300-12,000)
$15
($12-18)
$620
($500-740)
$32,500
($26,000-39,000)
Incremental Costs $5,000-20,000
From: www.werf.org/decentralizedcost
Frequently Asked Questions – Costs for Improved Management
Mgt. Indicators
● parcel size
● proximity to collection systems
● proximity to large parcels
Questions
Photo Credit: Residential Application of a Vegetative Tertiary Filter by WetlandsPacific Corporation in Vancouver, British Columbia
Webcast Resources
• Recommendations of the On-Site Wastewater Treatment Systems Nitrogen Reduction Technology Expert Review Panel
• Technical Appendix G: Requirements to Enter Advanced On-Site Wastewater Treatment Practices into Scenario Builder and the Phase 5.3.2 Watershed Model
• Appendix A: List of Resources for Making Informed On-Site Wastewater Technology Decisions
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