SpringsComparitives-5B

What’s Planning Got to do With It?

Comparisons Between Various Florida Springs

* Aquifer Vulnerability (FAVA)* Land Use

* Septic Systems Population& Population Growth

With Corrective Cooperative Actions & Strategies Applied Overtime

Photo - John Moran

• Springs are Important State Resources• Multiple Springs (in fact the majority of springs) in Florida are

experiencing serious deteriorating water quality conditions from nitrates.

• Some springs have the deteriorating water quality exacerbated due to declining water volumes from the contributing groundwaters

• All springs in Florida are naturally adapted to continual cycles of droughts and high rainfall - native ecological components are likewise adapted.

• The State water quality standard for most springs is .35mg/L nitrate at the spring vent - modifications can be made based on spring-specific data – often to less than .35mg/L.

Starting Points

1st Alapaha Rise

1st Alexander

1st Big Blue (Wacissa)

1st Blue Grotto

(Silver)

1st Blue Hole

(Ichetucknee)

1st Cedar Head

(Ichetucknee)

1st Chassahowitzka

1st Emerald (Gainer

#2)

1st Falmouth

1st Gainer #3

1st Homosassa

1st Ichetucknee

1st Kings Bay

1st Kini/Upper River

Sink

1st Lime Sink Run

1st McCormick

(Gainer #1)

1st Natural Bridge

1st Nutall Rise

1st Roaring

(Ichetucknee)

1st Silver

1st Siphon Creek Rise

1st Spring Creek

1st Steinhatchee Rise

1st Tarpon Hole

(Kings Bay)

1st Treehouse

1st Wakulla

1st Weeki Wachee

2nd Apopka

2nd Aucilla (Wacissa)

2nd Baltzell

2nd Beecher

2nd Blue Hole

2nd Branford

2nd Buckhorn Main

2nd Bugg

2nd Citrus Blue

2nd Columbia

2nd Copper

2nd Crystal Springs

2nd Cypress

2nd De Leon

2nd Devil’s

Ear/Eye/Little

2nd Ellaville

2nd Fanning

2nd Fenney

2nd Fern Hammock

2nd Gilchrist Blue

2nd Ginnie

2nd Guaranto

2nd Hart

2nd Hernando Salt

2nd Hornsby

2nd Hunter (Kings

Bay)

2nd Jackson Blue

2nd Juniper

2nd Lafayette Blue

2nd Lithia Major,

Minor

2nd Little River

2nd Madison Blue

2nd Manatee

2nd Morrison

2nd Otter

2nd Pitt

2nd Poe

2nd Ponce de Leon

2nd Rainbow

2nd Rock

2nd Rock Bluff

2nd Running East,

West

2nd Salt (Marion)

2nd Sanlando

2nd Santa Fe

2nd Santa Fe Rise

2nd Shangri La

2nd Starbuck

2nd Sun

2nd Suwanacoochee

2nd Suwannee

2nd Suwannee

Blue

2nd Telford

2nd Three Sisters

(Kings Bay)

2nd Troy

2nd Volusia Blue

2nd Vortex

2nd Wacissa Group

2nd Wekiwa

2nd White

2nd Williford

3rd Green Cove

3rd Little

3rd Orange

3rd Peacock

3rd Royal

3rd Waldo

3rd Warm Mineral

3rd Worthington

3rd[20] Welaka

4th Boulware

4th Gator

4th Glen

4th Levy Blue

4th Magnolia

NA Cow

NA Devil’s Den

NA Paradise[19]

Zero Holton Creek

Rise

Zero Kissingen

Zero Rossetter

2nd

St.

Marks

Rise

2nd Silver Glen

Many Springs, with State and Private Parks

Each creates a local Economy

Natural Gems and Recurrent Economic Generators

Important State Resources With Ecological and Human Health Problems that Link to:

* Springshed Land Uses (Pattern/distribution, Density and Intensity)

* Inadequacies of Facilities to support Land Use choices (Often Wastewater Facility Inadequacies)

* Other nitrate Pollutant Source(s) (e.g., Fertilizers)

*Inadequacy of Tools for Management of Sources

* Consumptive uses of source water reduce spring flow and concentrate pollutants

St. Johns River

Kings Bay/Crystal

River

Central Florida LAKES

Amoebas, in Central Florida waters concern health officials

With Too Many NutrientsPersonal and Ecosystem Health Can be Affected !

Indian River Lagoon

Vibrio vulnificus, a bacterium that lives in warm saltwater, can cause infections that can lead to death.

Aeromonashydrophila can be

found in freshwater and brackish water environmentsCausing rare cases of necrotizing fasciitis

Examples of Springs and Their Problem Sources

Areas where the aquifer is unconfined typically have the highest ground-water recharge rates and hence ground water in these areas is more vulnerable to contamination than areas where the aquifer is semi-confined or confined.

LEVY

Citrus

Hernando

Pasco

Florida Aquifer Vulnerability Assessment (FAVA) Mapping of the West Coast Springs Areas

EXAMPLE- 1: Multiple Florida West Coast Springs

The intrinsic beauty, ecological diversity, and multiple recreational uses make the coastal springs and estuaries of west-central Florida a unique and important water resource. (USGS 2001)

• Blue Stars – Large – 1st

Magnitude Springs• Blue Stars – Small – Smaller

Springs• Blue circles – Swallets – Open

holes to the aquifer

• Violet – Wastewater Treatment Facilities

• Red – BioSolids Disposal Sites/Sludge

• Arrows – General Direction of Groundwater Flow

• Blue lines – Potentiometric Surface – top of the aquifer –descending toward coast

Pasco County - Population & Projections 2015 - 2040Year: 2015 2020 2025 2030 2035 2040 Population 498,000 554,396 608,302 659,498 707,992 754,303

County Total OSTDS

Persons per

household

Average

annual input to

septic tank =

4.5 kgN/person

(FDOH)

Total

average

input = kg-

N/yr

Total kg-N/year

Minus a 40%

attenuation factor

(i.e., drainfield to

groundwater)

Total kg-N/Year

Adjusted for N

attenuation from

drainfield to

groundwater

Total Pounds

N/Year

Adjusted for N

attenuation from

drainfield to

groundwater

Pasco 245,141 2.52 4.5 2,779,899 -1,111,960 1,667,939kg 3,677,176

County Total OSTDS

Persons per

household

Average

annual

input to

septic

tank = 4.5

kg-

N/person

(FDOH)

Total

average

input =

kg-N/yr

Total kg-

N/year Minus

a 40%

attenuation

factor

(i.e.,

drainfield to

groundwater)

Total kg-

N/Year

Adjusted for

N attenuation

from

drainfield to

groundwater

Total Pounds

N/Year

Adjusted for N

attenuation from

drainfield to

groundwater

Pasco 245,141 2.52 4.5 2,779,899 -1,111,960 1,667,939kg 3,677,176

Citrus 65,555 2.33 4.5 687,344 -274,938 412,406kg 909,200lbs

Hernando 49,206 2.42 4.5 535,853 -214,341 321,512kg 708,813lbs

Levy 20,414 2.52 4.5 231,495 -92,598 138,897kg 306,215lbs

Totals

West

Coast

Springs

Counties

378,616 2.4475 4.5 4,234,591 -1,693,837 2,540,754kg 5,601,404lbs

Notes: Based on best available septic tank data for each county, or DOH model relying on tax parcel data and sewer service areas calculate number of people relying on septic tanks (# of septic systems x the estimated # of people per household for that county). Then multiply the number of people relying on septic tanks by the average annual input per person to septic tank (this is estimated at 4.5 kg-N/person (per FDOH). Then apply a 40% attenuation factor that addresses the fact that a certain amount of the N discharged is attenuated (i.e., converted to N gas, bound by soil or otherwise lost before it can enter the groundwater – per FDEP).

West Coast Springs: Influence of Septic SystemsAripeka (Pasco & Hernando), Weeki Wachee (Hernando & Pasco), Homosassa (Citrus), Crystal River/Kings Bay Citrus), Chassahowitzka (Citrus), Manatee (Levy)

Hernando County - Weeki Wachee Springshed

FAVA

Land Use

Septic Systems

DOH estimate there are more than 16,662 septic systems in the more contributing area of Weeki WacheeSpring. More are added each year. Each dwelling unit generally comes with a yard & fertilizers

Hernando County Weeki Wachee System

Before

After

FAVA Land Use

Citrus CountyCrystal River/Kings Bay

Septic Systems

DOH estimate there are more than 39,919 septic systems in the Kings Bay contributing area. More added each year. Each dwelling unit generally comes with a yard & fertilizers.

After

Citrus CountyCrystal River/Kings Bay

North Florida – Wakulla Springs

FAVA

Land Use

Septic Systems

#s indicate estimated septic systems in more vulnerable areas of springshed. More added each year.

Wakulla Springs

Before and After Photos

Can you tell the more recent?

Marion County - Rainbow River System


FAVA

Land Use

Septic Systems – In Indian Red

There are more than 8,279 septic systems situated in the Rainbow Springs springshed –with more added each year. Each dwelling unit generally comes with a yard & fertilizers.

Before

After


In Planning for Growth - Given our* Level of knowledge (Karst, direction of flows, movement of nitrate through Karst

environments, etc.)* Recently established numeric nitrate standards based on ecological health

* Number of TMDLs that help clarify particular springshed standards & pollutant sources.

We Need To Better Address Wastewater Infrastructure Options In These Karst Areas

Normal wastewater disposal options in vulnerable Karst areas that do not remove or lessen nitrate are contributory sources that overtime need to be corrected and/or

avoided

Commonly Used Wastewater Disposal Options Where Nitrate Inputs Can be Reduced* Rapid Infiltration Basin (RIBs) [Add Nitrate Removal]

* Land Application via Sprayfields [Add Nitrate Removal]* Concentrations/Populations of Standard Septic systems [Manage overtime to reduce,

eliminate or upgrade]* Biosolids disposal – [Eliminate land spreading of residuals]

OLD APPROACHES – NEED REVISIONS1. RIBs – Rapid Infiltration Basins

RAPID-RATE LAND APPLICATION SYSTEMS

• Infiltration basins need to be applied very carefully, as their use is often sharply restricted by concerns over groundwater contamination

• In regions of karst topography, these infiltration basins should not be applied unless adequate nitrate and pollutant technologies are in-place due to concerns of groundwater contamination and sink hole formation.

In Karst Environments,

2. Waste Water Treatment Facilities Using Sprayfields or Reuse Options to Dispose of Nitrate Laden Wastewater

WWTFs with nitrate removal technology and then discharge via sprayfields may offer a better option

3. LAND SPREADING OF WWTP/SEPTIC SLUDGE & RESIDUALS

Is Important to keep it OUT OF THE SPRINGSHEDS and Identified Karst Vulnerable Areas

Presently, A ban of Land Application of septagebecomes effective on January 2016

4. Concentrations of Septic Standard Systems in Vulnerable AreasA Land Use Density to Landscape Suitability Question

NOT specifically handled by a Reviewing Agency under Chapter 163, F.S.

The discharge plume of one or a few septic systems is non-consequential - The cumulative plumes that form due to concentrations of these systems can be a continuous source of

nitrates and other pollutants to groundwater or nearby surface - a serious problem!

The Good News?

Some local governments are facing the challenge!

They Understand The Sources Of The Problems And Are Making Headway To Develop The Programs/Actions To Begin To Correct Things

For Example : CITY OF TALLAHASSEE MARION COUNTY

Springshed X

Suburban/Urban

AgriculturalNatural or Heavily

Forested

SPRINGSHED LAND USES DIFFER FROM ONE ANOTHER - THE MIX OF PROBLEM NUTRIENT SOURCES DIFFER AS DO THE PROBLEM SOLUTION SETS

WQ Impairments – NitratesTMDL Guidance

Little-to-No WQ Impairment

Crop FertilizationAnimal Waste, Collection &

DisposalAquifer Depletion- Consumptive

Use

WWTPsSeptic Systems

Yard FertilizationStormwater

Aquifer Depletion –Consumptive Use

Aquifer Depletion –Consumptive Use From

Adjacent Land Uses

WQ Impairment – NitratesTMDL Guidance

Corrective ActionsUpgrade WWTP to remove nitrates/Next Permit Cycle

Establish local Septic System management entity/strategyStrong Education Program to reduce Yard Fertilization

Local Stormwater management/UtilityWMD Reins-in CUPs, sets MFL with Water Reservation for

Natural System ComponentsMONITER

Corrective ActionsDACS, IFAS works with farmers to implement strong BMP program

Controlled-Release FertilizerGPS Use

Precision ApplicationIrrigation Scheduling

Grassed Waterways andFilter Strips & Vegetative Buffers

Drip or Micro Irrigation MONITOR

Actions WMD Reins-in CUPs, sets MFL

with Water Reservation for Natural System Components

MONITOR

Florida Department of Environmental Protection

• FEDP has performed multiple monitoring and ecological studies on deteriorating springsheds and in most cases identified Nitrate as the central pollution problem.

• FDEP has been performing required Total maximum Daily Load (TMDL) for each springshed to establish: permissible pollutant limits for nitrate, sources of the nitrate and, likely proportions of nitrate attributable to a particular source type.

• FDEP, acting as a facilitator, works through the Basin Management Action Plan (BMAP) with source-type nitrate contributors and involved parties (called stakeholders) to identify actions over time to correct the identified problems. Identified actions are formalized via an adopted Final Order Basin Management Action signed by the FDEP Secretary.

Problem Solving Requires a Cooperative Approach

Many Of The Nitrate Source Pollution Problems Are Essentially Land Use, Infrastructure Provision And Management Problems.

Florida Department of Economic Opportunity• DEO, the state land planning agency, has a role as it works with local governments, developers,

citizens and other state, regional or federal agencies in the planning for sustaining and protecting of identified state resources and facilities.

• For Comprehensive Plan amendments in Areas of Critical State Concern or other amendments under the State Coordinated Process with identified State Resources and Facilities, DEO may consider the character of the undeveloped land, soils, topography, natural resources on site and raise issues that address land uses from a suitability perspective by evaluating densities and intensities of development, facility planning and the adequacy of infrastructure needed to support proposed land uses.

• DEO can offer comments, recommendations and objections to a plan or plan amendment for Comprehensive Plan amendments in Areas of Critical State Concern or amendments in the State Coordinated Process for identified State resources and facilities for areas of responsibility not being addressed by the other required reviewing agencies.

An Important State Agency Partner – FDEP, has only limited authorities – Generally no authorities of land use density and intensity, landscape suitability beyond jurisdictional wetlands protection and influence in the design/permitting of certain infrastructure – e.g., larger sanitary waste disposal facilities.

What does this information have to do with land use planning? DEO, Local governments, Community & Individual Actions?• In planning for development manage high nitrate contributory land uses and facilities in identified vulnerable

areas to reduce or limit nitrates, for example: The number and density of Lots on septic systems. Wastewater treatment facilities – ensure they treat to nitrate removal standards and where they don’t,

avoid discharge to RIBs and sprayfields. Work with the placement and management of high nitrate users such as golf courses.

• Facility planning for suburban/urban development in identified vulnerable springshed landscapes should ensure development is on central sewer that can treat to advanced standards to remove nitrates.

• Where the sanitary sewer facilities are septic systems, ensure lot/septic system densities are rural or rural suburban in nature (e.g., density 1DU/10acres or less) or, ensure use of performance-based septic systems with regular system management regimens stipulated

• Encourage local governments to establish a septic system management utility or Responsible Management Entity (RME) – possibly witin existing utility frameworks

• Make sure Golf Course “facilities” use careful nutrient management plans and practices to limit the application of nitrate fertilizers and CUPs that strive to conserve water.

• Encourage Local governments, HOA/development associations and related management entities to implement nutrient limiting management practices for yards/lawns, landscaping and right-of-ways that limit the application of nitrate fertilizers and offer regular resident education updates.

• Ensure Water conservation via planning and design of communities – the challenge for the future to use less water as these areas.

COMMENTS?

LOST SPRINGS OF FLORIDA

White Sulphur Springs (Hamilton County)

In 1903, the spring was enclosed by concrete and coquina walls that included multiple water gates and galleries to prevent water intrusion from river flooding. A four-story wooden bathhouse was constructed around the spring.

Through the 1980s, water flow at the spring declined to the point when it ceased flowing in 1990.

Uncaring Progress – From Eden to Disaster

Kissengen Spring in Polk County – 1894 to Present

A popular spot for cool down for generations – Lost to phosphate mining that reshaped the landscape and groundwater levels & flows

1894

Today

Peace River with old phosphate mined areas to the east and west

Circa 1910-20

Volusia Blue Springs

Blue Springs – Volusia County

Aquifer Vulnerability

Septic Systems

Land Use

There are more than 16,406 Septic Systems in the Blue Springs Springshed – more each year. Each dwelling unit generally comes with a yard & fertilizers.

Blue Springs – Volusia County

Santa Fe River Area Springs

Note how Gilchrist County is surrounded by these springs –its topography and geology delivers the water to this necklace of springs –

What happens land use-wise determines the water quality and quantity.

Springs of the Lower Suwannee and Santa Fe River Area (Gilchrist,

Lafayette & Suwannee Counties)

Fanning Above the water

Fanning below the water

Fanning Springs – A Natural Gem and Recurrent Economic Generator

Fanning Springs on the Suwannee River in Levy County has an average nitrate concentration above 5 ppm, or more than 100 times the background, and peak concentrations close to 10 ppm. The adopted water quality standard for Fanning Springs is .35 mg/L Nitrate-N

Hart Springs -A Natural Gem and Recurrent Economic

Generator

Poe Springs -A Natural Gem and Recurrent Economic Generator

Gennie Springs - A Natural Gem and

Recurrent Economic Generator

Nitrate levels in various springs surrounding Gilchrist County – From Mid 1990s to 2013 - Generally all exhibit upward trending levels

Nitrate Concentrations in wells – Gilchrist, Suwannee & Lafayette Counties

NOTE: Background nitrate nitrogen concentrations throughout areas where the Floridan Aquifer underlies protected lands (for example, the Ocala National Forest) are less than 0.05 parts per million nitrate (ppm or mg/L). For example Alexander Springs 2006 Averaged 0.055ppm nitrate – which is in the Ocala National Forest.

The adopted State water quality standard for most springs is .35ppm nitrate -though modifications can be made based on spring specific data.

About 40 percent of the wells sampled in Gilchrist County had nitrate concentrations above 1 ppm, more than 20 times the baseline. Fanning Springs on the Suwannee River in Levy County has an average nitrate concentration above 5 ppm, or more than 100 times the background, and peak concentrations close to 10 ppm. Test wells in Suwannee and Lafayette counties associated with row crops frequently have nitrate concentrations above 30 ppm (600 times the baseline), and a few wells have been recorded at concentrations greater than 100 ppm (2,000 times the background level).

A comparison of the area from 1994 to the present (2014).

The land uses have remained generally stable with Waccasassa Flats primarily silvaculture and the surrounding better drained areas to the east and west primarily crop and dairy farms. Ag has had significant nitrate pollution impacts to the surrounding springs.

The addition of sizable urban and suburban land uses to this historically agriculture area should proceed with caution and strive to lessen nitrate deterioration of springs on the Suwannee and Santa Fe rivers –

These spring collectively are important local economic contributors and important state resources.

• The Waccasassa Flats in the central part of Gilchrist County, Florida, comprise an area of about 125 square miles.

• The Flats are not actually flat, but instead consist of sand hills that represent a relict barrier island. The area is underlain by Miocene and Pleistocene clastics (Clay soils) that retard the percolation of water. This results in a perched water table and contributes to the wet and swampy nature where tree farming rather than row crops have been the predominate land use (unlike the lands to the east and west where row crop ag dominates).

• The Flats are actually the “higher” land in the area and represent a potentiometric high point.• The Flats are not level and tend to be slanted east (high) to west (low) – and like a table top,

surface and recharge water move toward the Suwannee River and Springs to the west, or at the north end of the Flats, to the north and the Santa Fe River and springs.

Gilchrist County Area

Levy County Manatee Springs (starred)

Groundwater-Relative Vulnerability

Land Use

Septic Systems Dispersal

Levy County has more than 20,414 septic systems Each dwelling unit

generally comes with a yard & fertilizers.

Levy County - Manatee Springs (Close-in)

• Overhead Irrigation/fertilizers• Community on Septic Systems• Golf Course - fertilizers

Levy County Manatee Springs

Additional Information

Citrus County Population & Projections

2015 2020 2025 2030 2035 2040

143,800 153,100 161,900 169,800 176,600 182,700

Census Designated Place (CDP) - Less than municipalities but more than rural – Incremental Suburbia

CDP - settled concentrations of population that identifiable by name but are not legally incorporated under the laws of the state. CDPs are delineated

cooperatively by state and local officials and the Census Bureau, following Census Bureau guidelines.

County Total

OSTDS

Persons/

household

Average annual

input to septic =

4.5 kg-N/person

(FDOH)

Total

input =

kg-

N/year

Total kg-

N/year Minus

a 40%

attenuation

factor

Total kg-

N/Year

Adjusted for

N

attenuation

Total Pounds N/Year Adjusted for

N attenuation

Citrus 65,555 2.33 4.5 687,344 -274,938 412,406kg 909,200lbs

2009 Sanitary Waste Disposal Septic System Facilities N Contribution

Levy County Population and Projections

2015 2020 2025 2030 2035 2040

41,300 44,300 46,900 49,100 51,100 52,800

Census Designated Place (CDP) - Less than municipalities but more than rural – Incremental Suburbia

CDP - settled concentrations of population that identifiable by name but are not legally incorporated under the laws of the state. CDPs are delineated


County Total

OSTDS

Persons

per

household

Average annual

input to septic

tank = 4.5 kg-

N/person

(FDOH)

Total

input =

kg-N/yr

Total kg-

N/year Minus

a 40%

attenuation

factor

Total kg-

N/Year

Adjusted for

N

attenuation

Total Pounds N/Year

Adjusted for N attenuation

Levy 20,414 2.52 4.5 231,495 -92,598 138,897kg 306,215lbs


Hernando County Population & Projections

2015 2020 2025 2030 2035 2040

180,200 198,000 214,700 230,200 244,700 258,100

Census Designated Place (CDP) – Less than municipalities but more than rural – Incremental Suburbia

CDP is a settled concentrations of population that identifiable by name but are not legally incorporated under the laws of the state. CDPs are delineated


County Total

OSTDS

Persons/

household

Average annual

input to septic =

4.5 kg-N/person

(FDOH)

Total

input =

kg-N/yr

Total kg-

N/year Minus

40%

attenuation

factor

Total kg-

N/Year

Adjusted for

N

attenuation

Total Pounds N/Year

Adjusted for N attenuation

Hernando 49,206 2.42 4.5 535,853 -214,341 321,512kg 708,813lbs


Teasing Apart Nitrogen’s Inorganic and Organic Sources- E.g. Yard and agricultural fertilizers vs septic

systems and WWTPs – at time some of both!

Work with the local governments to inventory and eventually prepare wastewater master plans that include: Upgrading WWT facilities to remove nitrates (in time). Remove/restrict sludge spreading in these springshed basins. Identify concentrations of septic systems that can be hooked to wastewater treatment

systems that remove nitrate. Identify where septic systems make the most sense at reasonable densities (less

vulnerable Karst areas) and identify which/where septic systems ought to be upgraded to performance-based systems.

Help local governments develop the management tools/apparatus to make these land use/facility decisions possible, logically implemented end economically viable (this is where there is a serious void and the evolving concept of establishing a local responsible management entity (RME or R-nutrient-ME) tool has been proposed).

Continue to work with the local governments, WMDs and developers to provide/replace stormwater treatment facilities via local and NPDES permitting processes, encourage use of stormwater utility development in the communities where one has not been established, and encourage basin and sub-basin stormwater master planning so that stormwater management to protect a waterbody can move beyond a patchwork of individual on-site facilities to a more systematic efficient and economic approach.

For existing Developed Areas

The Septic System Issues

What’s the Problem?

Estimation of the Nitrate Load often fails considering the overall landscape suitability to the greater septic systems population or density.

Any one septic system, taken individually, adds an in-significant contribution of nitrate to the groundwater environment.

Looked at collectively, as a population of such systems, the amount of nitrate added the groundwater can be quite significant and not “handled” by dilution, de-nitrification or soil binding.

In many areas of Florida this is the sanitary sewer facility infrastructure configuration

These facilities are permitted on a one-for-one basis by the County Health Departments without regard to water quality standards of adjacent of connected water bodies

This is the assumption regarding microbes and viruses and the fate of nutrients and pollutants –Research and now our TMDLs show us otherwise

What’s the Problem?

Estimation of the Nitrate Load often fails considering the overall landscape suitability to the greater septic systems population or density.

Any one septic system, taken individually, adds an in-significant contribution of nitrate to the groundwater environment. Looked at collectively, as a population of such systems, the amount of nitrate added the groundwater can be quite significant and not “handled” by dilution, de-nitrification or soil binding.

1. De-nitrification (e.g., biological use and metabolism and the gassing off as Nitrogen) can lessen the nitrate problem for one, or many septic systems. It is tied to soils, geology, available carbon source(s), oxygen supply and, distance or travel time to receiving surface or groundwaters.

2. Physical binding of excess nitrate to soil particles occurs where soils are conducive – Not so much in sandy Karst soils or where soil particles become saturated and travel time to receiving water is short.

3. Dilution of un-used nitrate in large volumes of water can assist but continuous nitrate additions by large numbers of septic systems can “overpower” dilution effects.

Hasn’t the assumption been the nitrate is handled by the soils, dilution, biological metabolism?

In sandy soils over a Karst geology where water percolates quickly into the underlying low oxygen groundwater (describes our many springsheds) – significant nitrate volumes (loads) result.

For waters, near lakes and lagoons for example, there may not be a porous Karst underlying geology and there is some organic/loamy soils, standard drainfield design (allowing proper separation between the bottom of the drain field and the receiving groundwater levels) may be removing some of the nitrate via de-nitrification.

Issues arises due to proximity of waterbody (short travel distance), density or population of the septic systems and, the fact that even properly maintained standard septic systems operating in proper soil conditions do not remove all the nitrate.

Thus, a few system – No Problem – Many systems – a continuous load of nitrate entering the receiving waterbody significant problems arise.

Documents

SpringsComparitives-5B