Household Hazardous Waste

Household Hazardous Waste in the Sanitary Landfill

Riley N. Kinman

Department of Civil and Environmental Engineering

University of Cincinnati

and

David L. Nutini

RNK Environmental, Inc.

Reprinted from Chemical Times and Trends Magazine, 1988

Household hazardous waste (HHW) disposal is a growing nationwide concern. HHW is perceived by some people to have a detrimental effect on the sanitary landfill environment and to require special collection programs to isolate it from the general waste stream.

This paper presents the results of a literature review, as well as ongoing research, to determine what volume of HHW might be reaching the sanitary landfill and their impacts. The exact impacts of these waste materials on the sanitary landfill are not known. However, data from solid waste research, codisposal research, and leachate and landfill gas characterizations are presented to help extrapolate what those impacts might be. Finally, benefits deed from collection programs versus placina HHW sanitary landfills are discussed, versus issues such as costs, liability, health and safety, and other related issues.

Waste Characterizations

Of the early literature searched, one hazardous household product waste characterization was a study performed by the Los Angeles County Sanitation Districts on two landfills: Puente Hills and Mission Canyon- Out of the 185 tons of waste sorted at Puente Hills landfill, only 107 gallons of liquid HHW were detected. Household loads contained 0.0045% and mixed and commercial loads contained 0.28% of potentially unacceptable material.

Of 2,056 containers found at the Mission Canyon landfill that had contained materials that could be classified as hazardous, 1,889 were empty (92%). Detailed records on the containers (empty or with residue) were classified into six categories:

40% Household and cleaning products

30% Automotive products

16% Personal products

8% Paint and related products

3% Insecticides, pesticides, Herbicides

4% Other products considered hazardous

Containers with a residue were estimated for the percentage of material remaining. For example, in one truckload, 99 hazardous material containers were found. All of these were empty except five containers. One was a 2.35-oz bottle of butane fuel about 30% full. Four other bottles found to have 10% of their original contents included: a 5-oz bottle of shaving lotion, a 5-oz can of insect killer, a 17-oz (aerosol) can of disinfectant, and an aerosol enamel paint can. Of a total of 155 tons of waste sorted at the Mission Canyon landfill, 48.8 gallons of material were found that could be classified as hazardous. Overall. 0.13% of the total refuse mass could be classified as HHW.

The conclusions drawn from this study were that:

• quantities of potentially hazardous waste disposed of in municipal waste are extremely small.

• the vast majority of materials inspected and detected were common products which would only be considered hazardous if received in large bulk loads;

• the small -quantity of this type of material is effectively absorbed by the solid waste,

• consumers do not appreciable quantities of materials that could be considered hazardous.

A more recent waste characterization study was performed in King County, Wash., in which 33.7 tons of waste were examined. This waste total comprised residential, commercial, industrial, and self haul samples. Data presented in this paper showed that the residential type waste had a nonregulated hazardous waste component of 0.1% of the total municipal solid waste landfilled. This was based on estimated residuals from the waste and did not include the containers in which they were packaged. An EPA study by Fungaroli and Steiner reported compositions of the refuse they sorted from a 11 city, in southeast Pennsylvania to contain 0.8% paints and oils. This was the only potentially HHW they reported. This is somewhat in line with the Los Angeles study. Although the percentage is higher solely for paints and oils. it is not reported whether this was totally residential, commercial, or mixed. As in most studies of this type, it is probably a mixture of commercial and residential waste.

On a smaller scale, Kinman has hand-sorted 532 pounds of municipal refuse from low to medium income homes in the Cincinnati, Ohio, area specifically looking for HHW. Removing the residual hazardous household products from their containers and weighing those residuals yielded a total weight of 0.52 pounds of material. Although based on small sample size, this amounted to 0. 1% of the total refuse mass, which is very similar to the previous studies There were many other waste characterizations found in the literature review. Most of these were characterizations of solid municipal wastes from various solid waste/codisposal projects. A total of 40 waste characterizations representing areas of the southern, midwestern, western, and eastern United States and western Canada were found. Generally, the municipal wastes actually ,g to a sanitary landfill are classified into 11 categories.

Note that none of the general categories specifically includes HHW. A composite of these characterizations is given in Table I. From the 40 characterizations, the mean and ranges are reported for each waste category. The reported percentages are based on a combination of wet and dry weights of these wastes. Note in Table I that the greatest average percentage of municipal solid waste is paper, which can effectively absorb small quantities of HHW. As seen in this table, this would generally be the case for any landfill because of the large quantity of paper waste characterized in a landfill.

Proponents for preventing HHW from being disposed of in sanitary landfills base their waste characterization figures on collection days and consumption survey. Table II is a composite from waste collection programs reported around the United States indicating that fairly large quantities have been collected. However, what is typically found in the day-to-day garbage can inspection or an inspection of waste compactors is not these large volumes of HHW.

Consumers typically don't throw wastes of these types away in bulk. What is thrown away can be handled at the landfill if it is properly maintained and operated. Remember that these collection day figures are generally based on a one-day collection. It does not indicate the time period this waste was accumulated by the participant before the one-day collection program occurred. These collection day data do not contradict the relatively low figures found in the other waste characterizations.

TABLE 1
Mean and Ranges of Waste Categories Characterized in 40 Waste Characterization
Studies Across the United States37
Category	mean. %	Range, %
Paper	46.7	36.5-54.7
Garden	9.5	0.4-25.0
Metals	8.5	4,0-14.7
Glass/ceramics	8.4	6.0-13.7
Food	7.8	0.9-18.2
Plastic, rubber, leather	5.3	2.0-9.0
Fines	4.2	3.0-6.1
Textiles	3.3	0.7-5.0
Wood	2.6	0.5-7.0
Rock, ash, dirt	2.5	0.5-10.0
Dirt	1.5	0.5-2.9

Landfill Leachate and Gas

Once waste characterizations have determined the amount of HHW entering the sanitary landfill, the true impacts should be determined by studying the effects of these wastes on the leachate and the gas from the landfill. Unfortunately, no studies have looked specifically at HHW impacts on sanitary landfill leachate and gas. However, the studies referenced below were performed with municipal refuse and codisposed refuse (municipal plus industrial sludges). Some of the industrial sludges would be similar to some HHWs, only in larger quantities. For example, some sludges used in these studies include solvent-based paint sludge, battery production waste, and chlorine production brine sludge.

The studies examined the leachate from the site; i.e., contaminated water produced as rain or other water infiltrates the refuse in a landfill site. The character of the leachate depends on the types of wastes received into the landfill, the material available for solution, cover material, the age of the landfill, biological activity, chemical activity, and the quantity of the infiltration water. Pohland and co-workers point out that the leachate quality and quantity are site-specific.

However different in quality and quantity, several research projects on solid municipal waste indicate that leachate toxicity decreased with time. In two projects in which leachates have been monitored for up to 10 years, the leachate concentrations have peaked within the first year of leachate production (or after the landfill reached field capacity) and tapered off over the remainder of the studies.

Table III shows data for leachates in a young landfill (less than one year old), in a medium landfill (five years old) and in an older landfill (ten years old). The young and medium landfill data are taken from Cameron and Koch, whereas the 10 year sample is taken from Kinman et al. The pH of young landfills is generally more acidic, as seen in Table M. The other parameters listed tend to decrease with the age of the landfill, thus decreasing the toxicity of the leachate. This indicates that biological activity is taking place and that the wastes are being detoxified and treated within the lando. The leachate becomes less strong as time and nature do their job.

It was noted that Cameron and Koch also measured natural leachates directly from landfills and found them to be less toxic than the lysimeter "synthetic- leachates." Table IV shows the data for their measurements of the natural leachate. This shows that nature does do her job, reducing toxicity while degrading materials.

TABLE II
Examples of Household and Small Small Business Hazardous Waste Disposal Programs
Location	Waste Collected	No. of Participants
Anchorage, Alaska (I 982)	1,000 lbs + 35 barrels waste oil	48 households, 41 businesses
Palo Alto, Calif. (1983-1984)	Fall: 30 55-gal drums	150 households
		Spring: 55 55-gal drums
Redlands, Calif. (1984)	175 gal liquid	30 households
		75 lbs solid
Sacramento, Calif. (1982,	1982: 54 drums, 2,400 lbs oil or recycling	1982: 250 households
	1984)	1984: 900 households
		1984: 165 drums
San Diego, Calif. (1984)	13,626 lbs in 5,057 containers	202 pickups, 88 people went
		to collection site
Woodland, Calif. (1984-l985)	33 55-gal drums + 100 gal motor oil	106 households
Florida (1 984)	250 lbs	50 schools, 86 gov't agencies,
		2,513 households, 277
		businesses
Barristable, Mass. (1983)	8,000 gals in bulk + 144 gals of waste	500+ households
		oil
Lexington. Mass. (1982-1983)	86 55 gal drums	316 households
Seattle, Wash.	6 gals, 90 lbs pesticides, 3 qts solvents,	65 households
		40 gals oil
Madison, Wis.	2,872 lbs	325 households
San Bernardino, Calif.	60 drums	? I
Orange County, Calif.	270 drums	600
Midland, Mich.	3,000 lbs, mostly paint. 10% pesticides	89
Ann Arbor, Mich.	110 gals paint, 35 gals solvent, 3 drums	83
		toxic chemicals, 100 lbs lye
Lexington, Mass. (1982)	7 55-gal drums paint, 4 drums pesticides	93
Andover, Mass. (1983)	165 gals paint, 55 gals oil, 55 gals	43
		waste, poisonous liquid, 30 gals pesticides
Bedford, Mass.	7 55-gal drums paint, 1 0 drums pesticides,	67
		fertilizers, asbestos, misc.
Greater Fan River area, Mass.	3 55-gal drums paint, 1 drum flammable	30
(6 towns) (1983)	liquid, 1 drum pesticides, 1 drum acid
Braintree, Mass. (1983)	6 55-gal paint, 7 drums oil, 2 drums	65
		flammable liquid, 1 drum acid. 3 30-gal
		drums pesticides, 10 5-gals flammable solvents

TABLE III
Chemical Composition of Landfill Leachate with Time10, 14
Parametera	1 year	5 years	10 years
pH	4.8-5.2	5.0-6.6	5.6-6.1
Chemical oxygen demand	19,700-45,300	137-34,900	293-10,600
Total organic carbon	7,300-16,350	83-9,150	108-3,080
Total solids	10,000-33,000	718-18,400	1,920-5,530
Total volatile solids	5,350-20,330	124-10,300	770-3,330
Alkalinity	4,100-7,700	184-7,600	1,240-2,900
Chloride	620-1,880	5.3-730	115-193
Cadmium	0.005-0.89	<0.001-0.162	<0.05-0.009
Chromium	0.09-16.8	0.003-0.410	<0.025
Copper	0.03-0.12	0.009-0.09	<0.025
Iron	308-1,136	195-1,820	98.7-855
Lead	0.077-3.15	0.003-0.082	<0.05-0.08
Nickel	0.15-0.79	<0.005-0.342	<0.040-0.127
Zinc	46-298	0.18-75	<0.025-0.167
a All units are in milligrams per liter except pH.

Although leachate toxicity is reduced with time for some parameters, it may still be considered toxic. For example, another study compared the chemical characteristics of leachate from an operating section and from a 20-year-old abandoned section of a landfill in southeastern Pennsylvania. The authors noted (Table V) significant reductions in biochemical oxygen demand and chemical oxygen demand, whereas other parameters were reduced but less significantly. They concluded that the abandoned section, although less toxic, was still considered a source of contamination.

Small quantities of HHW in sanitary landfills do not keep the microorganisms from doing their job of biodegradation. HHW have little effect on leachate or gas quality.

Although leachate is toxic, it is not toxic because of HHW alone. All residential wastes have the "ingredients" to cause leachate toxicity, primarily from the breakdown of organic wastes placed in the sanitary landfill, including the "nonhazardous" materials such as paper, food, fecal matter, leaves, leather, metal, etc. Therefore, the threat would exist even if the "hazardous" household wastes were eliminated from the refuse.

In the case where it may still be a potential threat to water supplies, the leachate must be collected and treated. Several reports indicate that leachate can be treated effectively through recycling, physical treatment, combined physical/chemical treatment, conventional activated sludge plants, separate anaerobic and aerobic biological processes, public-owned treatment works (POTWS) or combinations of these.

TABLE IV
Natural Leachate Analysisb
	Natural
Parameter	leachate
pH	6.3-7.8
Chemical oxygen demand	720-4,720
Total organic carbon	810-1,600
Total solids	3,190-6,490
Total volatile solids	1,092-2,930
Alkalinity	1,350-3,510
Chloride	125-2,400
Cadmium	0.001-0.004
Chromium	0.025-0.085
Copper	0.01-0.05
Iron	1.6-30.3
Lead	0.023-0.065
Nickel	0.002-0.069
Zinc	0.43-1.32
b All units are in milligrams per liter except pH.

 

TABLE V
Leachate Comparison Between an Operating Section and a 20-year-old Abandoned of a Landfill in Pennsylvania28
Parametersa	Operating	Abandoned
Specific Conductance	3,000	2.5
Biochemical oxygen demand	1,800	15
Chemical oxygen demand	3,850	246
Ammonia-Nitrogen	160	100
Hardness	900	290
Iron (total)	40.4	2.2
Sulfates	225	100
a All units are milligrams per liter except specific conductance (microohms).

Certain studies have also examined substances that result from the decomposition of modern municipal refuse measured in landfill gas. Anaerobic conditions lead to the carbon containing compound conversion to methane (CH₄) and carbon dioxide (CO2), the two principal gases in landfill gas. In addition to these two major components. there are a large number of trace compounds in the gas.

One of the experimental goals is to be able to model the decomposition process in sanitary landfill. Table VI contains the trace volatiles in landfill gas. Several compounds were spiked into the experimental landfills so that spiked cells and unspiked cells could be compared. Note that all of the samples from the test cells contained the three compounds used in the spike: benzene, ethylbenzene, and toluene. Concentrations of benzene were about one-fourth of that in the spiked cell. Toluene concentrations exceeded one of the spiked cell concentrations in some of the samples. Ethylbenzene also exceeded the spike cell levels in some of the samples. This indicates that there are materials in the refuse that decompose to yield higher concentrations of the three compounds than when the refuse was specifically spiked to yield higher measureable concentrations of these compounds. Thus, they are there, even if one tries to eliminate them.

This is clear from Table VI, which has the compounds (benzene, toluene, and ethylbenzene) grouped according to relative concentrations found in landfill gas. All three compounds are very common solvents used in the manufacture of ingredients for some household products. Benzene is used for organic compound synthesis and, therefore, may be contained in some paints and inks. Ethylbenzene and toluene are used in paint manufacture and many coating materials. These compounds were found in all experimental landfill samples. Highest concentrations were in decreasing order: toluene, 128 mg/m³; ethylbenzene, 105 mg/m³-, and benzene, 12.2 mg/m³, respectively.

In summary, leachate toxicity and gas production in a sanitary landfill. due specifically to HHW, are not found anywhere in the technical literature. However, based upon studies of codisposed municipal and industrial waste, it appears that landfill leachate and gas will have toxic components, regardless of whether the landfill contains HHW. Fortunately, in most cases, if a sanitary landfill is properly engineered, is on a suitable site, and is maintained and operated properly, leachate should not present a threat to groundwater or surface water supplies. The suggestion here is that the landfill acts biologically and chemically on the waste materials to make them less toxic. Nature, in time, will degrade the waste to a considerable extent. At the same time. the collection and treatment of the leachate is recommended to render a safe effluent.

TABLE VI
Trace Volatile Organic Compound Concentrations at 25ºC
				Lysimeter (sample date)
	21b,c	21c	22	22	23b	33	35
Compound.	(5/22/55)	(6/20/55)	(6/20/55)	(7/01/85)	(5/22/85)	(6/20/85)	(6/20/85)
Pentane	NDd	6.42	0.2	1.33	Pe	ND	2.13
Tetrahydrofuran	ND	ND	0.406	ND	ND	0.653	0.408
Freon	ND	67.7	0.203	13.3	ND	1.08	ND
Benzene	12.2	12.1	1.02	1.05	0.4	1.3	0.821
Dichloromethane	0.05	27.7	0.71	54.1	0.017	2.71	0.321
Hexane	P	101	1.02	26.4	P	1.08	2
Toluene	11.2	128	20.3	21.1	3.62	33.5	48
1.1-Dichloroethylene	0.04	ND	ND	ND	0.032	ND	ND
1.2-Dichloroethylene	0.99	0.54	1.31	1.85	1.27	ND	0.651
1.1-Dichloroethylene	ND	ND	ND	ND	ND	ND	ND
o,m,p-Xylenes	13.3	175	112	118	12.2	249	120
Ethylbenzene	8.78	105	24.4	25.1	4.58	68.3	97.1
Chlorobenzene	ND	ND	ND	ND	ND	ND	ND
Isooctane	ND	ND	ND	ND	ND	ND	ND
benzene	ND	ND	ND	ND	ND	ND	ND
Propylbenzene	p	33.7	8.11	11.8	ND	ND	3
Carbon disulfide