GlauconitGlauconite e

(Greensan(Greensand)d)

A Peculiar Soil ConstituentA Peculiar Soil ConstituentFred H. Bowers, Ph.D., Princeton Soil Institutewww.PrincetonSoilInstitute.com

What is Glauconite?What is Glauconite?• Called Greensand Marl• Sand-size particles or pellets (See figures below)• Normal sand sized particles consist of discrete minerals

such as quartz, orthoclase, calcite, etc.• Glauconite sand-size particles are made up of relatively

stable pellets of clay-size mica (Clay). • The pellets generally range from about 0.5 to 0.05 mm in

diameter with some being as much as 4 mm cemented with clay-size siderite.

• Produces good structure when undisturbed

DistributionDistribution• New Jersey has some

325,000 acres of greensand (glauconite-bearing) soils

Water Holding Character

NUTRIENTS: Contains up to about 7-8% potash (K2O) and, in some instances, a little more (Hower, l.c.).

Water and Nutrient Water and Nutrient CharacteristicsCharacteristics

Table 1. Quantity of Moisture Retained in Various Soils and Greensand Deposits at Two Tension Levels (unpublished data of Prof. N. A. Willits).

SoilSoil 6 Atm Tension 6 Atm Tension

% Moisture% Moisture

15 Atm 15 Atm TensionTension

% Moisture% Moisture

SassafrasSassafras 2.32.3 1.31.3

HornerstownHornerstown 2020 16.416.4

Effects of Glauconite on Effects of Glauconite on Septic System FunctionalitySeptic System Functionality

• Tricky Evaluations (due to texture by hand)• Mottling

• Enhanced due to moisture holding• Oxidation of reduced iron on peds

• Construction• Smearing when constructing with backhoe • Do it by hand

• Clogging and chemical changes• Susceptible to deflocculation from salts from

water softener backwash

Soils of Glauconite AreasSoils of Glauconite Areas• FreeholdFreehold• CollingtonCollington• Colts NeckColts Neck• AdelphiaAdelphia• MarltonMarlton• KressonKresson

How to Ensure a How to Ensure a Functioning Septic System Functioning Septic System

in Glauconitein Glauconite• Standard septic tank fieldsStandard septic tank fields

– Mottling can suggest SHWT but not be accurate. Mottling can suggest SHWT but not be accurate. Look at soil series. Look at associated vegetation; Look at soil series. Look at associated vegetation; Obtain a soil scientist when in doubtObtain a soil scientist when in doubt

– Design disposal field as if it were clay (K class K0 Design disposal field as if it were clay (K class K0 for under-drain requirements)for under-drain requirements)

– Do not smear or alter the glauconite. Dig trenches Do not smear or alter the glauconite. Dig trenches by hand.by hand.

• Drip irrigation into the upper soil horizons Drip irrigation into the upper soil horizons that avoid floodingthat avoid flooding

• Lay down a layer of ASTM 33 sand on the Lay down a layer of ASTM 33 sand on the glauconite to form the biomat and form glauconite to form the biomat and form transition to claytransition to clay

• Avoid using water softenersAvoid using water softeners