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[Paper assembled by Author: page numbers added: Publication ISBN 0-646-35127-3
Dent, B.B. and Knight, M.J., 1998, Cemeteries: A special kind of landfill. The context of their sustainable
management., Groundwater: Sustainable Solutions, Conference of the International Association of
Hydrogeologists, Melbourne, Feb. '98, 451 – 456]
Cemeteries: A Special Kind of Landfill.
The context of their sustainable management.
Boyd B. Dent 1 and Michael J. Knight1
1National Centre for Groundwater Management, University of Technology, Sydney,
Broadway, NSW 2007, AUSTRALIA
ABSTRACT: In Australia, the National Study of Cemetery Groundwaters has been underway for 1.5 years.
This is a general hydrogeochemical and microbiological assessment of groundwaters in aquifers and as seepage
at 9 cemeteries, representing a considerable range of hydrogeological settings and soils. The interment (burial)
of human remains occurs within a complex paradigm of factors. Firstly, the range of natural aspects of the land,
its hydrogeology and climate; secondly, the management practices of the cemetery; thirdly, the funereal aspects
of the interment, for example, whether the remains are included in a coffin or not, or the presence of clothing
and artefacts; fourthly, the remains themselves including their age, size, and state of decomposition at burial.
Cemeteries are best thought of as special kinds of landfill in that they mostly comprise a limited range of
essentially organic matter covered by soil fill. Although they don’t necessarily create new space (like area
landfilling), the processes are akin to landfill cells below grade. Degradation follows different, somewhat less
predictable pathways than landfill. An understanding of the proper interrelationships of the various factors at
any cemetery is important in scientifically establishing its viability for re-use; the true sustainability of the site
including its impact on groundwater.
KEYWORDS: cemeteries, landfill, interment, re-use, planning
1.0 INTRODUCTION
In Australia in 1996 approximately 46% of all funeral services resulted in interment (burial) of the
deceased (ACCA, 1997). Whilst this percentage reflects the growing trend towards cremation as a
preferred disposal option for the deceased in westernised societies, the proportion opting for interment
means that significant grave space needs to be found.
Using average death rates and "Low Case" population projections, as per the Australian Bureau of
Statistics (ABS, 1996), then about1.34 million Australian adults (>15 years) will die in the next 10
years (1998-2007). If just 40% of these are interred, and 75% of them occupy new graves of an
average size 1.1m by 2.4m; then 106ha of land will be consumed.
Most of this consumption, 67ha, will occur in the greater metropolitan areas of the capital cities,
since this is where approximately 63% of the population lives. This is roughly equivalent to 1100
standard building blocks of 600m2 each, and makes no allowance for associated paths, roads, gardens
and other infrastructure. Clearly this is a significant urban space requirement and a considerable
exposure to the processes of the hydrologic cycle.
The majority of the cemeteries in our major urban areas are now well demarked by other land
uses, and their boundaries well defined by historic land dedications. There is little room for expansion
of existing sites and most included space is either full or being rapidly consumed. Most of our capital
cities are now seeking land for cemetery dedication in the urban fringe areas, which to some extent
goes with expanding populations and urban sprawl. However, in only a few known cases, notably in
Melbourne, Victoria, is there sufficient free land to accommodate such activities. Concomitantly, the
city dwellers show a low inclination to bury their dead great distances from their homes, with the
consequence that older, closer-in cemeteries are facing disproportionate pressures for burial space.
In Adelaide, South Australia, these pressures can be clearly seen at work in a large outer, but
confined, and a small, old, inner-city, cemetery – Centennial Park and Cheltenham General
respectively. By a fortuitous combination of the right-of-burial legislation in that State, and the
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geography of the Adelaide urban area, these cemeteries are widely invoking the management practices
of grave re-tenure and re-use.
Grave re-use essentially comprises two forms; firstly where a relative to a previously deceased is
interred in the same grave, but at a shallower depth than the original interment. This practice is
widely used at most cemeteries; non participation in this practice usually results from various religious
or cultural bases. Secondly, the South Australian practice of "lift and deepen" is used. In this
situation, previously interred remains that are no longer licenced for exclusive burial, say by the
expiration of a 50 or 100 year lease, are gathered together in to an ossuary box or bag which is then
re-interred below the original grave invert, and the grave space then becomes available for standard
burials (up to three per grave) again.
The Australian industry is keen to develop and extend the re-use/re-tenure concept to answer the
problems of inadequate grave space into the future. This is a common practice for varying lengths of
interment in many overseas countries, and seems to be gaining acceptance where it is being used
today. At first glance this appears to be a sustainable land use.
2.0 NATIONAL STUDY
With such pressures and practices as outlined, and in any case since it is largely an unknown, it
behoves society to consider whether there are any deleterious aspects to the burial of the deceased and
re-use of burial lands. Are there any primary or cumulative influences on the environment?
In 1996 the National Study of Cemetery Groundwaters was conceived in order to apply rigorous
scientific investigation towards answering these questions. Nine cemetery sites located in five states
and representing a diverse range of hydrogeological environments are currently being investigated.
Seventy two piezometers have been installed; a number of these in specially designed seepage wells
or trenches constructed in the unsaturated zone. Sampling from these piezometers will occur for about
6 events, completing at the end of 1998.
All water samples are being broadly screened for a wide range of inorganic analytes, as well as
BOD, and a suite of microbiological (bacterial) indicator organisms including coliform species,
Faecal streptococci, and Pseudomonas aeruginosa. In previous work, at Botany Cemetery, New
South Wales, Dent (1995) found that the array of common anions and ammonia, were the most
diagnostic for discerning decay products from interred remains. Strict protocols for piezometer
construction, sampling, equipment cleaning and testing are used in all sites, and all sampling is
undertaken by the senior author only.
There is a vast array of ethical and practical problems to be resolved in establishing any one site.
No sampling points are located in graves. The confined nature and/or high usage rate of many
cemeteries makes them difficult sites in which to establish piezometers. In particular it is often
difficult to establish unequivocal background sampling points; especially when working from the
position that all sampling points must be located within the cemetery boundaries.
3.0 HYDROGEOLOGICAL INTERACTIONS
When rain falls on a cemetery the usual interactions of the landuse and the hydrologic
cycle must apply. The water can either re-evaporate, pool, run off, or infiltrate in or on the
land and its structures. When water infiltrates it will come in to contact with interred remains
and the artefactual materials that occur with them. According to the individual
hydrogeological setting of the cemetery, natural attenuation of the hydrogeochemistry and
biota will occur, or not, as the case may be. The decay products may leave the cemetery
boundaries depending on the degree of constituent accumulation, flow paths of the water, the
relative location of remains in the cemetery and many other factors.
3.1 Factors
The amount of decay products moved from the interred remains to the watertable is
extremely difficult to quantify in space and time. Although it is possible to define an area of
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newer interments with an accessible watertable in some cemeteries, like Botany, this is the
exception rather than the norm.
In most cemeteries there is likely to be one or more "General" areas currently being
utilised for those deceased with no particular religious, familial or cultural affiliations. Other
factors that affect the interment rates are whether or not the area is completed with lawn,
monuments or a combination of these. Moreover, these practices seem to reflect cemetery
operations and societal preferences most strongly developed in the last 20 years or so.
By far the most common operational practice, and one which significantly affects
quantitative studies, is the highly variable spatial and temporal emplacement of remains.
Burials take place in widely different parts of the cemeteries at different times. The picture is
further complicated in the older, fuller sites where interments are by re-use of a family plot.
This causes a vertical variation in time and space as the new interment sits on previously
filled and/or collapsed soil and grave structures. The larger the cemetery, the more likely this
variation is to occur.
The primary hydrogeological setting (particularly noting the water budget, types of soil,
and use of fill in the ground grading) is the first influence on the resultant cemetery
hydrogeochemistry. However, other factors also play a significant part in determining what
sort of decay loads can enter the soil and water. These fall into 2 more groupings; firstly the
funereal aspects of the interment, for example, whether the remains are included in a coffin or
not, the coffin construction, encapsulation of the remains in plastic, the presence of clothing
and artefacts in and around the coffin; secondly, the remains themselves including their age,
size, state of decomposition at burial, and other aspects that may relate to cultural attitudes,
post mortem examinations and/or embalming.
The resultant pathways and composition for any decay products are thus very complex.
In most sites observed, the individual grave also acts as a bucket and sponge. The disturbed
nature of the soil (even when watered back in to place to assist consolidation) in the grave,
even if covered with lawn or monument, attracts and holds water for varying lengths of time.
Thus areas of cemeteries which were initially dry to dig are frequently wet at grave level and
seepage is observable from grave to grave. This situation is exacerbated by the long term
usage (at least since the mid 1970s), in most areas, of plastic lined coffins. Until the weight
of overlying soil, or the decay processes collapse the coffin, it also remains as a bucket. An
important effect of this is that the coffin bucket holds many decay products, further affecting
the temporal and spatial release of these products to the ground.
The National Study in part attempts to focus on encapsulation aspects related to
religious/cultural practices but it is uncertain whether this can be delineated on a cemetery-
wide scale. The influence of coffin type, for example pine, hardwood, steel, bronze,
cardboard and fastenings and ornamentation, may also have measurable effects. The practice
of embalming is relatively uncommon in Australia, but wherever practiced may also
contribute to a measurable effect, for example in the detection of formaldehyde. The only
known examinations of this aspect however, Chan et al. (1992) and BEAK (1992), did not
find any significant effect, although they were quite limited studies.
3.2 Groundwater Composition
The groundwaters in aquifers beneath cemeteries clearly reflect regional
hydrogeochemistry and additions from the decaying remains. Seepage waters on the other
hand are more likely to represent short term soil-water interactions and any readily mobile
decay products; which in terms of mass, mostly derive from the human remains.
The reference, lean, 70kg adult male, human body contains: 16,000g carbon, 1,800g
nitrogen, 1,100g calcium, 500g phosphorous, 140g sulfur, 140g potassium, 100g sodium, 95g
chlorine, 19g magnesium, 4.2g iron and water 70 – 74% by weight; the female proportions
are 2/3 - 3/4 of these (Forbes, 1987). Proportions for most of the other elements – trace
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elements and heavy metals, rapidly decrease to milli- and micro-mole amounts. Cadmium for
instance is 0.05g, and mercury is highly variable depending on lifetime exposure and dental
fillings.
The sampling for the National Study is from very diverse hydrogeological settings and
some indication of these is noted in Table 1. This table shows the analyses of background
and downgradient groundwater samples from three sites representing three rounds of
sampling from each, compared to similar wells or bores wholly located within the cemeteries.
Seepage wells are 450mm diameter and are used as temporary storages in sites dominated by
spring flow or low hydraulic conductivity soils. The comparative well at The Necropolis is
topographically downgradient, and at the boundary.
The sites considered are: Woronora, in a southern Sydney suburb, New South Wales,
where residual sandy clays and minor clayey sands, often lateritised, overly a quartz
sandstone (Hawkesbury Sandstone formation) with substantial siltstone lenses (the seepage
wells are at 2.0-4.5m depth); The Necropolis, at Springvale a southeastern suburb of
Melbourne, Victoria, where densely unconsolidated, firm clays to 10-12m overly sandy silts,
silty sands (Brighton Group) containing a phreatic aquifer at 14-28m (the seepage wells are at
2.5-5.5m depth); Guildford an eastern suburb of Perth, Western Australia, where
unconsolidated shallow marine deposits of clayey and silty sands and fine sands (Bassendean
Sand) have a phreatic aquifer at 1.8-4.5m (3m piezometer screens straddle the watertable).
Table 1
Analyte Woronora The Necropolis Guildford
mg/L or
CFU/100mL 1x
background 2x internal
seepage wells comparative
seepage well 3x internal
seepage wells 1x
background
2x bores
downgradient
at boundary
EC µS/cm 509-922 236-684 241-263 608-2204 603-1127 216-667
pH units 5.5-6.6 5.0-7.4 5.6-6.3 6.3-7.5 6.2-7.3 5.8-6.1
NO2-N 0-0.001 0-0.003 0-0.002 0-0.056 0.002-0.315 0-0.015
NO3-N 0.2-0.3 0-1.16 0-2.2 0-14.3 0.4-6.3 4.1-33.2
NH3-N 0-0.39 0.2-4.72 0-0.79 0-0.22 0.1-0.45 0-0.50
Tot N 0.10-0.25 0.55-3.9 0.3-0.8 1.2-21 1.0-4.2 18.1-45.0
PO4 0 0-0.85 1.6-2.55 0.5-1.6 0-1.9 0.06-4.7
Cl 85-170 24-41 40-45 42-390 133-160 20-33
SO4 57-77 17-56 3.2-3.7 48-290 66-95 0-21
TOC 2.0-19 1.6-12 2.0-4.0 0-30 58-73 4.0-23
BOD 5-21 3-16 4-6 0-9 <5-22 <5
Tot coliforms 0-2 0->500 0 3->2400 0-8 0-8
E. coli 0 0-2 0 0-10 0 0
F. streptococci. 0 0 0 0-22 0 0
Pseudomonas 0 0-4 0 0 0 0-11
From an examination of Table 1 it becomes apparent that the results show considerable
variation and are overall low values. Furthermore, the internal waters often appear to have
lower concentrations of inorganics than the background waters, for example, chloride, sulfate,
TOC, BOD, pH and electrical conductivity (EC). It must be borne in mind, however, that
only a few, early, results are presented here. From the same analysis it can also be said that
the internal cemetery waters are significantly higher in nitrogen, phosphate, and bacterial
contents.
These data alone are evidence that decay products are measurable and could have an
influence elsewhere in the environment. If one begins with the premise that no waste
products of any burial activity should leave the generating site's boundaries, then there is
room for consideration of what levels of off-site movement of decay products can be
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permitted. In addition, what management/operational strategies should be implemented to
limit this movement.
The sampling to date has taken place in a time period of reduced rainfall over much of
Australia and all the sites discussed. It is possible that in some situations higher rainfall
regimes will alter the concentrations of decay products, and as watertables rise, make them
more readily available to groundwater systems.
4.0 MANAGEMENT PRACTICES
Typical management practices in cemeteries, mostly driven by public health legislation,
require that all burials take place above known watertables. Most cemetery operators also
look for sites with deep soils which, because of their clay content, will be able to be
excavated by machine and have walls that will stand up for at least 24 hours. In less
favourable locations, or for aesthetic or operational reasons, some areas are extensively filled.
The results of the present National Study certainly endorse the strict burial of remains
above watertables. The presence of the pathogenic bacteria Pseudomonas aeruginosa and
Feacal streptococci, widely found throughout the sites, albeit in small to very small amounts,
as well as other indicator coliform bacteria suggest, that in some hydrogeological settings,
microbiological decay products are being carried in the groundwaters. The chemical analyses
also show slightly elevated nutrients and other solutes related to the decay processes. In
many cases the affected waters are free to leave the cemetery boundaries.
What does not seem to have been appreciated in the past however, is that cemeteries, like
much of their surrounding districts, frequently contain permanent or seasonal, perched
watertables. These are often reflected in springlines which has lead to some areas being free
from interments, but such seepage is sometimes not seen at the surface. When burials
commence in such areas, the decay processes are strongly influenced by the presence of extra
moisture and the resultant products are more susceptible to movement. In addition, in all
cases, the bucket effect is at work which increases ground moisture, and creates ephemeral
watertable effects. Many cemetery areas are irrigated for lawn and garden purposes. This
practice further distorts the natural water budget and encourages the wetting up of graves.
5.0 CEMETERIES AS LANDFILL
Cemetery processes are complex; they vary widely in time and space. It is convenient to
develop a model in order to comprehensively consider the role, impact and operations of a
cemetery entity. Cemeteries are a special kind of landfill. In essence, small quantities of
organic waste are placed below surface level and covered with soil. No new ground is
created, yet an excess of overburden accumulates. The site is well developed in a parklike
manner and the area reserved from future occupation or building, in perpetuity. The sites are
large and occupy a significant place in the hydrologic cycle with which they readily interact.
Traceable plumes of decay products are generated and these could move offsite. The whole
hydrogeochemistry relies on natural attenuation, although there could be some effect of
accumulation of metals in skeletal materials whilst they persist.
This is most comparable to an unlined trench or cell for disposal of municipal wastes. In
the case of cemeteries, however, there are probably fewer processes at work, working at
different rates, and much less controlled (Figure 1). They are particularly subject to the soil
composition and structure. The interred materials are not excluded from atmospheric
interaction, and oxygen (via the soil) and freely moving water, are present in the graves.
Various soil conditions limit this interaction.
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Figure 1 Comparison of Landfills
Typically, proposals for cemetery development do not seem to generate the high level of
investigation and geoscientific focus that landfills do. Neither do they result in the extensive
ground preparation and staged conceptualisation of operations of the landfills. These are
serious deficiencies. There are now sufficiently strong grounds for asserting that cemeteries
must have buffer zones on all boundaries but particularly on topographic lows and lowermost
portions of hydraulic gradients. These should be planted with substantial, deep-rooting,
native trees that will consume large volumes of groundwater, rather than lawns that are
unlikely to do this and which may also permit excessive infiltration. No interment should lie
at the cemetery boundary. Buffer zones in sandy areas should be larger than those in clayey
soils but at the present cannot be prescribed for size. The development of cemeteries from
the outside-in may assist in dispersing deleterious solutes, microbiological organisms or
nutrients, and limiting their concentration as they will not now flow from older to newer
burial areas.
On balance, cemeteries strongly distort the local hydrologic cycle, and operators,
managers and designers of cemeteries should take this into account. New cemetery proposals
and extensions should be properly assessed from a geoscientific perspective prior to detailed
planning. The likelihood of off-site groundwater movement needs to be investigated and an
assessment made of within-cemetery soil/operational aspects.
6.0 REFERENCES
Australian Bureau of Statistics (ABS), 1996. Projections of the Populations of Australia,
States and Territories, 1995-2051. Report 3222.0, Aust. Govt. Publishing Service, 139p.
Australian Cemeteries & Crematoria Association (ACCA), 1997. Cremation in Australia.
ACCA News Winter, pp.16-17
Beak Consultants Limited (BEAK), 1992. Soil and Groundwater Quality Study of the Mount
Pleasant Cemetery. Rept. for Commemorative Services of Ontario and Arbor Capital Inc.,
unpub.
Chan, G.S., M. Scafe and S. Emami, 1992. Cemeteries and Groundwater: An Examination of
the Potential Contamination of Groundwater by Preservatives Containing Formaldehyde.
Rept. Water Resources Branch, Ontario Ministry of the Environment, 11p.
Dent, B.B., 1995. Hydrogeological Studies at Botany Cemetery, New South Wales. M.Sc.
Proj. Rept., Univ. of Tech., Sydney, unpub.
Forbes, G.B., 1987. Human Body Composition; Growth, Aging, Nutrition, and Activity.
Springer- Verlag, New York, 380p.
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