ASTM D1987-95

Standard Test Method for Biological Clogging of Geotextile or Soil/Geotextile Filters

SCOPE
1.1 This test method is used to determine the potential for, and relative degree of, biological growth which can accumulate on geotextile or geotextile/soil filters.
1.2 This test method uses the measurement of flow rates over an extended period of time to determine the amount of clogging.
1.3 This test method can be adapted for nonsaturated as well as saturated conditions.
1.4 This test method can use constant head or falling head measurement techniques.
1.5 This test method can also be used to give an indication as to the possibility of backflushing and/or biocide treatment for remediation purposes if biological clogging does occur.
1.6 The values in SI units are to be regarded as the standard. The values provided in inch-pound units are for information only.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Dec-1996
• Technical Committee: D35 - Geosynthetics
• Drafting Committee: D35.02 - Endurance Properties

Relations

• Replaced By: ASTM D1987-95(2002) - Standard Test Method for Biological Clogging of Geotextile or Soil/Geotextile Filters
• Effective Date: 10-Dec-1996
• Referred By: ASTM E2777-20 - Standard Guide for Vegetative (Green) Roof Systems
• Effective Date: 10-Dec-1996
• Referred By: ASTM D5819-22 - Standard Guide for Selecting Test Methods for Experimental Evaluation of Geosynthetic Durability
• Effective Date: 10-Dec-1996
• Referred By: ASTM D4439-23b - Standard Terminology for Geosynthetics
• Effective Date: 10-Dec-1996
• Referred By: ASTM D7931/D7931M-21a - Standard Guide for Specifying Drainage Geocomposites
• Effective Date: 10-Dec-1996

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 1987 – 95
Standard Test Method for
Biological Clogging of Geotextile or Soil/Geotextile Filters
This standard is issued under the fixed designation D 1987; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method is used to determine the potential for, 3.1 Definitions:
and relative degree of, biological growth which can accumulate 3.1.1 geotextile, n—a permeable geosynthetic comprised
on geotextile or geotextile/soil filters. solely of textiles.
1.2 This test method uses the measurement of flow rates 3.1.2 permeability, n—the rate of flow of a liquid under a
over an extended period of time to determine the amount of differential pressure through a material.
clogging. 3.1.2.1 Discussion—In geotextiles, permeability refers to
1.3 This test method can be adapted for nonsaturated as well hydraulic conductivity.
−1
as saturated conditions. 3.1.3 permittivity, (C)(t ), n—of geotextiles, the volumet-
1.4 This test method can use constant head or falling head ric flow rate of water per unit, in a cross sectional area head
measurement techniques. under laminar flow conditions.
1.5 This test method can also be used to give an indication 3.1.4 aerobic, n—a condition in which a measurable volume
as to the possibility of backflushing and/or biocide treatment of air is present in the incubation chamber or system.
for remediation purposes if biological clogging does occur. 3.1.4.1 Discussion—In geotextiles, this condition can po-
1.6 The values in SI units are to be regarded as the standard. tentially contribute to the growth of micro-organisms.
The values provided in inch-pound units are for information 3.1.5 anaerobic, n—a condition in which no measurable
only. volume of air is present in the incubation chamber or system.
1.7 This standard does not purport to address all of the 3.1.5.1 Discussion—In geotextiles, this condition cannot
safety concerns, if any, associated with its use. It is the contribute to the growth of microorganisms.
responsibility of the user of this standard to establish appro- 3.1.6 back flushing, n—a process by which liquid is forced
priate safety and health practices and determine the applica- in the reverse direction to the flow direction.
bility of regulatory limitations prior to use. 3.1.6.1 Discussion—In other drainage application areas,
this process is commonly used to free clogged drainage
2. Referenced Documents
systems of materials that impede the intended direction of flow.
2.1 ASTM Standards:
3.1.7 biocide, n—a chemical used to kill bacteria and other
D 123 Terminology Relating to Textiles microorganisms.
D 1776 Practice for Conditioning Textiles for Testing
3.2 For definitions of other terms used in this test method,
D 4439 Terminology for Geotextiles
refer to Terminology D 123 and D 4439.
D 4354 Practice for Sampling of Geotextile for Testing
4. Summary of Test Method
D 4491 Test Method for Water Permeability of Geotextiles
by Permittivity 4.1 A geotextile filter specimen or geotextile/soil filter
D 5101 Test Method for Measuring the Soil-Geotextile composite specimen is positioned in a flow column so that a
System Clogging Potential By the Gradient Ratio designated liquid flows through it under either constant or
G 22 Practice for Determining Resistance of Plastics to falling head conditions.
Bacteria 4.1.1 The designated liquid might contain micro-organisms
from which biological growth can occur.
4.2 Flow rate is measured over time, converted to either
permittivity or permeability, and reported according.
4.2.1 Between readings, the test specimen can be allowed to
This test method is under the jurisdiction of ASTM Committee D-35 on
be in either nonsaturated or saturated conditions.
Geosynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-
4.2.2 Back flushing can be introduced from the direction
ance Properties.
Current edition approved Dec. 10, 1996. Published June 1996. Originally opposite to the intended flow direction and evaluated accord-
published as D 1987 – 91. Last previous edition D 1987 – 91.
ingly.
Annual Book of ASTM Standards, Vol 07.01.
4.2.3 Biocide can be introduced with the back flushing
Annual Book of ASTM Standards, Vol 04.09.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 1987
liquid, or introduced within the test specimen, and evaluated
accordingly.
5. Significance and Use
5.1 This test method is performance oriented for determin-
ing if, and to what degree, different liquids create biological
activity on geotextile filters thereby reducing their flow capa-
bility. The use of the method is primarily oriented toward
landfill leachates but can be performed with any liquid coming
from a particular site or synthesized from a predetermined
mixture of biological microorganisms.
5.2 The test can be used to compare the flow capability of
different types of geotextiles or soil/geotextile combinations.
5.3 This test will usually take considerable time, for ex-
ample, up to 1000 h, for the biological activity to initiate, grow,
and reach an equilibrium condition. The curves resulting from
the test are intended to indicate the in situ behavior of a
geotextile or soil/geotextile filter.
5.4 The test specimen can be incubated under non-saturated
drained conditions between readings, or kept saturated at all
times. The first case allows for air penetration into the flow
column and thus aerobic conditions. The second case can result
in the absence of air, thus it may simulate anaerobic conditions.
FIG. 1 Flow Column to Contain Geotextile Test Specimen
5.5 The flow rate can be determined using either a constant
head test procedure or on the basis of a falling head test
located above the filter are desired, the upper flow column of the
procedure. In either case the flow column containing the
permeameter can be modified to accommodate such measurements.
geotextile or soil/geotextile is the same, only the head control
Recommended are ports immediately above the filter (as close to it as
devices change.
1 1 3
possible), and at ⁄4, ⁄2, ⁄4 and above the soil or solid waste in question.
Duplicate ports on each side of the permeameter at the above elevations
NOTE 1—It has been found that once biological clogging initiates,
are considered good practice in measurements of this type. Other
constant head tests often pass inadequate quantities of liquid to accurately
configurations are at the option of the parties involved.
measure. It thus becomes necessary to use falling head tests which can be
The ports are connected by flexible tubing to a manometer board for
measured on the basis of time of movement of a relatively small quantity
readings in a manner that is typical for measurements of this type. See Test
of liquid between two designated points on a clear plastic standpipe.
Method D 5101, the Gradient Ratio test, for additional details.
5.6 If the establishment of an unacceptably high degree of
6.2 Hydraulic head control devices, are required at both the
clogging is seen in the flow rate curves, the device allows for
inlet and outlet ends of the flow column. Fig. 2 shows the
backflushing with water or with water containing a biocide.
complete setup based on constant hydraulic head monitoring
5.7 The resulting flow rate curves are intended for use in the
where concentric plastic cylinders are used with the inner
design of full scale geotextile or soil/geotextile filtration
cylinders being at the elevation from which head is measured.
systems and possible remediation schemes in the case of
landfill lechate collection and removal systems.
6. Apparatus
6.1 The flow column and specimen mount, consists of a 100
mm (4.0 in.) inside diameter containment ring for placement of
the geotextile specimen along with upper and lower flow tubes
to allow for uniform flow trajectories (see Fig. 1). The flow
tubes are each sealed with end caps which have entry and exit
tubing connections (see Fig. 1). The upper tube can be made
sufficiently long so as to provide for a soil column to be placed
above the geotextile. When this type of combined soil/
geotextile cross section is used, however, it is difficult to
distinguish which material is clogging, for example, the soil or
the geotextile. It does however simulate many existing filtra-
tion systems. In such cases, a separate test setup with the
geotextile by itself will be required as a control test and the
difference in behavior between the two tests will give an
indication as to the contribution of soil clogging to the flow
reduction.
FIG. 2 Flow Column with Inlet and Outlet Hydraulic Head Control
NOTE 2—If piezoemetric heads in the material (soil or solid waste) Devices for Constant Head Test
D 1987
The elevation difference between the inner cylinder at the inlet requirements of the following section can be met. Take a
end and the inner cylinder at the outlet end is the total head sample that will exclude material from the outer wrap and inner
across the geotextile test specimen (or soil/geotextile test wrap around the core unless the sample is taken at the
specimen in the case of a combined test column). Note that the production site, then inner and outer wrap material may be
elevation of the outlet must be above the elevation of the used.
geotextile. 7.3 Test Specimens—From the laboratory sample select the
6.3 A hydraulic head standpipe, above the flow column is number of specimens as per the number of flow columns to be
required for falling hydraulic head monitoring. Fig. 3 shows evaluated. Space the specimens along a diagonal on the unit of
this type of test configuration in which a clear plastic standpipe the laboratory sample. Take no specimens nearer the selvage or
is placed above the flow column. Liquid movement is moni- edge of the laboratory sample than 10 % of the width of the
tored for the time of flight between two marks on the standpipe. laboratory sample. The minimum specimen diameter should be
Note that the elevation of the outlet must be above the 100 mm (4.0 in.) so that full fixity can be achieved around the
elevation of the geotextile. inside of the flow column.
6.4 The overall test system, dimensions are sufficiently
8. Conditioning
small so that either of the above mentioned units can be used
8.1 There is no conditioning of the geotextile test specimen,
at a field site if desirable. They can either be kept stationary in
per se, since this test method is a hydraulic one and the
the laboratory or in the field, or they can be transported from
conditions of the permeating fluid will be the controlling factor.
the laboratory to the field site when required.
See also Practice D 1776.
6.5 The permeating liquid, is generally site specific and
often comprises landfill leachate. Other liquids for which 8.2 The relative humidity should be 100 % except during
times of air drying between nonsaturated test readings. For
biological clogging is of concern can also be evaluated. The
liquid can be synthesized on an as-required basis. saturated conditions the relative humidity should always be
100 %.
NOTE 3—A synthesized liquid which has been used in determining the
8.3 The temperature of the test over its entire duration is
resistance of plastics to bacteria is Pseudomonas aeruginosa ATCC 13388
6 important. It is desirable to track temperature continuously. If
or MYCO B1468. Specific details must be agreed upon by the parties
not possible, frequent readings at regular intervals are required.
involved. See also Practice G 22.
9. Procedure
7. Sampling
9.1 Procedure A—Constant Head Test:
7.1 Lot Sample—Divide the product into lots and take the
9.1.1 Select and properly prepare the geotextile test speci-
lot sample as directed in Practice D 4354.
men. Trim the specimen to the exact and full diameter of the
7.2 Laboratory Sample—For the laboratory sample, take a
inside of the flow column.
swatch extending the full width of the geotextile of sufficient
9.1.2 Fix the geotextile test specimen to the inside of the
length along the selvage from each sample roll so that the
containment ring. If a water insoluble glue is used be sure that
any excess does not extend into the flow area of the geotextile.
9.1.3 Caulk the upper surface of the geotextile to the inside
Available from American Type Culture Collection, 12301 Parklawn Drive,
of the containment ring using a silicon based caulk and allow
Rockville, MD 20852.
it to completely cure. The caulk must be carefully placed so as
Available from Mycological Services, P.O. Box 126, Amherst, MA 01002.
not to restrict flow through the geotextile.
9.1.4 Insert the upper and lower tubes into the containment
ring and create a seal. If polyvinyl chloride (PVC) tubing and
fittings are being used, first a cleaner and then a solvent wipe
is used to make the bond.
9.1.5 If a screen or gravel of approximately 50 mm (2 in.)
size is necessary to support the geotextile it must be placed
with the device in an inverted position.
9.1.6 Place the lower end cap on the device and make its
seal.
9.1.7 If soil is to be placed over the geotextile, place it at
this time. Place the soil at its targeted moisture content and
density taking care not to dislodge or damage the geotextile
beneath.
9.1.8 Place the upper end cap on the device and make a
permanent seal.
9.1.9 Connect flexible plastic tubing from the flow column’s
top and bottom to the head control devices. At this point the
system should appear as shown in the photograph of Fig. 2.
9.1.10 Adjust the total head lost to 50 mm (2.0 in.) and
FIG. 3 Flow Column with Standpipe for Variable (Falling) Head
Test initiate flow via the introduction of the permeating fluid to the
D 1987
system. When using leachate, proper safety and health precau- 9.2.11 Allow for flow through the system until the liquid
tions must be maintained depending upon the nature of the level reaches the upper mark and then start a stopwatch.
leachate itself. 9.2.12 Allow flow to continue unimpeded until the liquid
level reaches the lower standpipe mark and immediately stop
NOTE 4—It is suggested to use 50 mm (2 in.) total head difference since
the stopwatch so as to record the elapsed time.
this is the prescribed value used in the permittivity test of Test Method
9.2.13 Repeat this measurement procedure three times. The
D 4491. Other values of head or hydraulic gradient, as mutually decided
average of this value is to be r
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