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

Eberhard.Roeder@flhealth.gov Elke.Ursin@flhealth.gov

850-245-4250 Ext. 2698 (850) 245-4070 x 2708

Xueqing Gao, Ph.D.

Xueqing.Gao@flhealth.gov

(850) 245-4579

Bureau of Environmental Health