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Division of Disease Control and Health Protection
To protect, promote and improve the health of all people in Florida through integrated state, county, and community efforts.
Onsite Sewage Treatment and
Disposal Systems in Florida
Onsite Sewage Program
Bureau of Environmental Health
June 28, 2017
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f l o r i d a h e a l t h . g o v / F LW M I
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Florida Water Management Inventory
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Wastewater Disposal Drinking Water Source
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h t t p s : / / g i s . f l h e a l t h . g o v / F L W M I
Searchable Web Application
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How Inventory Can Help with Onsite
Wastewater Management
• Estimating nitrogen load contribution
• Identifying high priority areas for remediation
projects
• Choosing appropriate remediation methods to
help with Basin Management Action Plan
implementation
• Providing basis for nitrogen loading modeling
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Nutrient Contributors
• 38% of impaired water bodies in Florida are nutrient impaired
• Onsite wastewater systems are one of several contributors
• There are between 2.1 to 2.7 million onsite wastewater systems in Florida
• Nitrogen released from onsite wastewater systems to groundwater depends on several site-specific factors
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Study
Grouping
TN
(mg/L)
Flow
(gpd)
Person
s
Input/
capita
(lb/yr) Data source Florida
Studies 57 400 5 13.9 Anderson, 1998
(pre-Wekiva)
62 180 4 8.5
Nielsen et al. 2002,
McAvoy et al. 2002
Wekiva
Studies 74 315 5 14.2 Seminole Site, 2007
43 450 4 14.7 Lake Site, 2007
69 35 1 7.3 Orange Site, 2007
WERF
Wakulla 44 59 2 3.9 F1 Lowe et al. 2009
(means) 74 125 4 7.0 F2 Lowe et al. 2009
68 139 2 14.1 F3 Lowe et al. 2009
68 141 2 14.0 F4 Lowe et al. 2009
44 137 3 6.4 F5 Lowe et al. 2009
71 105 3 7.7 F6 Lowe et al. 2009
Wakulla
(medians) 54 104 2.5 6.8LT site, Katz et al 2010
30 431 4 9.8HK site, Katz et al 2010
47 161 2 11.5YG site, Katz et al 2010
Average 57 10
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Nitrogen Removal
Nitrogen exists in various forms and must be dealt with progressively in each form to ensure removal
Conceptually:
organic nitrogen-> ammonia -> nitrate -> nitrogen gasammonification nitrification denitrificationseptic/anaerobic aerobic anoxic (need food)
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Conventional OSTDS
drainfield
sewage
Septic Tank
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Aerobic Treatment Unit (ATU)
aeration tank drainfield
sewage
Septic Tank
NSF40 Certification
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aeration tank
recycle
aeration chamber
drainfield
drainfield
recycle
sewage
sewage
Examples for Nitrogen Removal
Processes
30%
40%
50%
60%
70%
80%
90%
0 5 10 15 20 25
Effluent TN (mg/L)
Fra
cti
on
TN
rem
oved
(%
)
NSF40-facilities
ETV
OWNRS/FAST
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Some Test Center Results of Nitrogen
Reduction Technologies
70%
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Additional Nitrogen Removal Processes
aeration
tank
denitrification
(food addition,
special media)drainfield
sewage
Septic Tank
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FLORIDA ONSITE SEWAGE
NITROGEN REDUCTION STRATEGIES STUDY
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Stage 2
(denitrification)
Stage 1
(nitrification)
Reduce effluent N using reactive media for
denitrification and a single liquid pump, if necessary.
denitrification media:
lignocellulosics & elemental sulfur
Wastewater from home
nitrification media:
sand & expanded clay
Dispersal
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“Passive” Nitrogen Reduction Systems
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Nitrogen Reduction at Field Sites
Full Scale Concepts Complement
Existing Septic Systems
In-Tank Passive Nitrogen System
In-Tank Two Stage Biofilter with Recirculation Stage 1, Dual
Media Stage 2 Lignocellulosic (2a) followed by Elemental
Sulfur (2b)
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Case Study: Groundwater Monitoring
18Image Credit: Hazen and Sawyer
(a) (b)
Existing
Drainfield
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Conventional OSTDS + In-Ground Two Stage System: Stage 1
Sand, and Stage 2 Lignocellulosic Materials
In-Ground Passive Nitrogen System
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Nitrogen Reduction Options for
Onsite Wastewater
Conventional
systems
Lined drainfield
& existing
advanced
technologies
Two-Stage
Nitrogen
reducing
systems
30%
70%93%
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Prescriptive Standards
If you build it this way, we believe that it will work for normal operations
Versus
Performance Standards
Design and build it to achieve specific performance requirements
Permitting Approaches
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Permitting Categories
Three categories include elements of
performance-based permitting
• Aerobic Treatment Unit (ATU)
• Performance-Based Treatment System
(PBTS)
• Innovative System (sub-category of
performance-based treatment system)
These categories require maintenance
entities, service contract agreements and
operating permits
Proposed Rule Revisions
• Phased-in implementation of in-ground nitrogen–
reducing biofilters as a prescriptive design (Issue
15-02)
• Inclusion of aerobic treatment units certified for
50% nitrogen reduction (NSF 245) in the
permitting category for ATUs (Issue 16-03)
• Status: The Department’s Technical Review and
Advisory Panel (TRAP) approved the issues at
meetings on March 31, 2017 and April 21, 2017
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Division of Disease Control and Health Protection
To protect, promote and improve the health of all people in Florida through integrated state, county, and community efforts.
Eberhard Roeder, PhD, PE Elke Ursin, PMP, CPM
[email protected] [email protected]
850-245-4250 Ext. 2698 (850) 245-4070 x 2708
Xueqing Gao, Ph.D.
(850) 245-4579
Bureau of Environmental Health