Pesticide Environmental Fates Toxicity

Appendix D



Detailed Analysis of Delta Contaminant Sources

Appendix D, Delta Dredge Strategy D-2







Sources of contaminants: Detailed Analysis



I. DELTA CERCLA SITES



The Comprehensive Environmental Response, Compensation and Liability Information

System (CERCLIS) is EPA's database and management system that inventories and

tracks hazardous/toxic releases which have been addressed or need to be addressed by the

Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)

Superfund program.



Many CERCLA sites within the Delta region have the potential to impact sediment

quality and effect dredged material management. To aid in determining the contaminants

of concern for proposed dredging projects, information on CERCLA sites having a direct

impact on Delta waters and sediments were gathered from the CERCLIS database. The

identified sites were grouped into regional categories (North, South…). Each regional

area is summarized and followed by a brief description of the relevant CERCLA sites

found within that region. Dredging projects near these CERCLA sites should address the

contaminants identified at those sites.



1. North Delta Area Summary:



There are five relevant CERCLA sites in the North Delta that may potentially impact

sediment quality and effect dredged material management. These sites include three sites

in Sacramento County and two in Yolo County.



The two Yolo County sites, CPB Deseret Farms and Simplot sites, are currently in the

discovery stage and little information is available. In Sacramento County, sites include

the Jibboom Junkyard, White Rock Road and Sacramento Army Depot. The White Rock

road site is currently undergoing preliminary site inspection and little information is

available. The other two Sacramento sites addressed are on the National Priority List or

have been removed from the list.



A. Jibboom Junkyard: The Jibboom Junkyard in Sacramento County is a

nine acre site located on the east bank of the Sacramento River. The property was

used for a metal salvage operation where all types of metals were salvaged along

with railroad cars, army tanks, batteries and transformers. The EPA and DOHS

conducted seven sampling investigations and from extensive lead, zinc, and

copper contamination on-site. Subsurface contamination above background levels

was detected at only four locations. The site was placed on the NPL in 1983.i



In 1991, EPA concluded that site cleanup efforts had effectively restored the site

to conditions that are protective of public health, welfare, and the environment

and the Jibboom Junkyard was removed from the NPL, however, there remains

the potential for prolonged existence of the identified chemicals in sediment.

Appendix D, Delta Dredge Strategy D-3





B. Sacramento Army Depot: The Sacramento Army Depot is a 485-acre site

used as an electronic maintenance and repair facility. From 1947 to 1972, paint

sludge, oil, grease, solvents and other industrial wastes were disposed of on-site

and in burn pits that extend 21 feet deep. Burned material was covered with soil

and revegetated. Part of the site consists of four lagoons, several drainage ditches,

and the neighboring Old Morrison Creek. Investigations showed that the

oxidation lagoon pits were contaminated with 11 heavy metals found in

concentrations of up to10,900 mg/kg. VOCs, metals, PCBs, dioxins and furans

have contaminated the burn pits on site. The primary contaminants of concern are

arsenic, chromium and lead. The site was placed on the NPL in 1987. The site is

currently undergoing inspections and remediation/cleanup efforts.



C. White Rock Road

There is little available information on the White Rock Road site. The site is

located in the Rancho Cordova area and should not impact Delta dredging

projects.



2. Southeast Delta Area Summary



In the southeast part of the Delta there are three sites that may impact sediment quality

and dredged material management; the, Stockton Navel Communication Station,

McCormick and Baxter Creosoting Co. and the Sharpe Army Depot, which are all

located in San Joaquin County. The Stockton Navel Communication Station is currently

undergoing site inspection. The McCormick and Baxter Creosoting Co. and the Sharpe

Army Depot are both on the National Priority List.



A. Stockton Navel Communication Station: The Stockton Navel

Communication Station (NCS) is located in Stockton on Rough and Ready Island,

which is bordered by the Stockton Deep Water Ship Channel to the North and the

San Joaquin River to the East and Burns Cutoff the south and west. The

Stockton NCS occupies two 13-acre parcels located in the northeastern section of

the island. The site contains landfills, disposal trenches, burning pits and wet

garbage disposal sites, all of which have been covered with soil to an unknown

depth and form 2-10 foot high mounds. Materials disposed of in these locations

include liquid paints, solvents, lacquers, motor oil, antifreeze, pesticide

containers, asbestos-containing materials and automobile parts. Contaminants

detected in the soil include, OC pesticides, PCBs, PAHs, oil/grease, copper,

phenols, mercury, cadmium, barium, lead, tin, nickel and zinc.ii



B. McCormick & Baxter Creosoting Co.: The McCormick & Baxter Superfund

site is a 29 acre site including Old Mormon Slough which connects to the

Stockton Deep Water Ship Channel and the San Joaquin River. The site was a

former wood treatment facility that used chemical preservatives containing

creosote, pentachlorophenol (PCP), arsenic, chromium, copper and zinc. In

addition, petroleum based fuels such as fuel oil, kerosene, diesel, butane and ether

were also used. Site drainage into Old Mormon Slough was uncontrolled from

Appendix D, Delta Dredge Strategy D-4





1942 to 1990. The site was placed on the National Priority List in 1992, and is

currently undergoing remediation and cleanup.

Remedial investigations (White & Kohn 1996) of the McCormick and Baxter site

have identified PCPs, PAHs, dioxins, arsenic, copper, and chromium. The

contamination extends up to 50 feet deep in the soil. Site Investigations have also

found high levels of dioxins, furans, PCBs, and PAHs in the sediments of Old

Mormon Slough. While some remediation efforts have been made on land at the

site, no remediation of Old Mormon Slough has occurred to date.



C. Sharpe Army Depot: The Sharpe Army Depot was placed on the National

Priority List in 1987. The Depot was formerly used as a maintenance facility for

repair and reconditioning of both heavy equipment and aircraft. Waste generated

from these maintenance activities came primarily from paint striping, metal

finishing and painting. Random dumping and accidental releases of hazardous

materials has lead to soil and groundwater contamination. Stormwater from this

site discharges to the South San Joaquin Irrigation District Canal, which

discharges into the San Joaquin River through French Camp Slough. The primary

contaminants of concern at the site are TCE, arsenic, lead and chromium. The site

is currently undergoing remedial actions.



V. CALIFORNIA 303(d) LIST

Section 303(d) of the Clean Water Act requires regulatory agencies to periodically assess

the waters of the state by an evaluation of the exceedance of water quality objectives. All

water bodies that do not meet water quality objectives are placed on the section 303(d)

list along with the constituents and sources that may be causing the impairment. In the

Delta region there are two areas classified as impaired that are of concern for potential

dredging projects in the Delta. These areas are listed as the Delta Waterways and the

Stockton Deep Water Ship Channel.



Under the Clean Water Act, any waterbody listed on the 303(d) list must have an

associated total maximum daily load (TMDL) developed for the contaminant of concern

impacting the waterbody. The TMDL determines the maximum amount of a pollutant

that a waterbody can receive and still meet water quality objectives.



1. Delta Waterways



The Delta Waterways encompass 1,153 square miles with approximately 1,000 linear

miles of waterway extending from the lowest part of the Central Valley at the confluence

of the Sacramento and San Joaquin Rivers inland to the Cities of Sacramento and

Stockton. The delta waterways total an approximate 480,000 acres and are impacted by

several pollutants.

The highest priority pollutants affecting the entire Delta include, chlorpyrifos and

diazinon originating from agricultural and urban runoff/storm sewers, mercury from

abandoned mines, and organic enrichment/lowD.O. from municipal point sources and

urban runoff. Delta Pollutants given medium priority by the 303(d) list include electrical

Appendix D, Delta Dredge Strategy D-5





conductivity originating from agricultural runoff, and toxicity arising from unknown

sources. The contamination from unknown toxicity affects the entire Delta while the

problem with electrical conductivity occurs over only 16,000 Acres from the San Joaquin

River at Vernalis to Grant Bridge, including Old River and Middle River. Finally, group

A pesticides are classified as low priority pollutants causing impairment throughout the

Delta.



2. Stockton Deep Water Ship Channel



The Stockton Deep Water Ship Canal covers approximately 37 miles (mile 4.4 to mile 41

in region 5. Two miles of the Stockton Deep Water Ship Canal, mile 38 to mile 41, are

included on the California 303(d) list of impaired water bodies. Studies of fish in the area

have shown high levels of contaminants in fish tissue and have resulted in the issuance of

fish advisories. The pollutants affecting this area as listed on the 303(d) list are given

medium priority and include dioxins, furans and PCBs.



A summary of the impaired water bodies found on the 303(d) list that are relevant to

dredging activities in the Delta are listed below.



1998 California 303(d) List and TMDL Priority Schedule

Region 5 Delta Waterways

Pollutant/Stressor Source Priority Size Affected

Chlorpyrifos Agriculture High 480,000 Acres

Urban Runoff/Storm Sewers

DDT Agriculture Low 480,000 Acres

Diazinon Agriculture High 480,000 Acres

Urban Runoff/Storm Sewers

Electrical Agriculture Medium 16,000 Acres:

Conductivity San Joaquin River

at Vernalis to

Grant Bridge,

including Old

River and Middle

River

Group A Agriculture Low 480,000 Acres

Pesticides*

Organic Municipal Point Sources High 75 Acres:

enrichment / Low Urban Runoff/Storm Sewers Turner Cut to

D.O. Port of Stockton

Unknown Source Unknown Medium 480,000 Acres

Toxicity**

Region 5 Stockton Deep Water Ship Channel

Pollutant/Stressor Source Priority Size Affected

Dioxin Point Source Medium Mile 39 to 41 of

the Deep Water

Ship Canal

Appendix D, Delta Dredge Strategy D-6





Furans Point Source Medium Mile 39 to 41 of

the Deep Water

Ship Canal

PCBs Point Source Medium Mile 39 to 41 of

the Deep Water

Ship Canal

 * Group A pesticides include aldrin, dieldrin, chlordane, endrin, heptachlor, heptachlor epoxide,

hexachlorecyclohexane (including lindane), endosulfan and toxaphene

 **Investigations into this toxicity are currently underway





Delta Agricultural Chemical Analysis :



Source List: Although hundreds of chemicals are reported to the Department of

Pesticide Regulations, we narrowed the scope to the most commonly used chemicals in

the five Delta Counties. The list of chemicals was compiled from the top 20 chemicals

(by volume) reported to Department of Pesticide Regulations in 1998 in Contra Costa,

Sacramento, Yolo and Solano counties, and the top 40 pesticides used in 1998 in San

Joaquin county (San Joaquin County has a much higher volume of chemical use than the

other counties). Although most of the chemical application is from production

agriculture, some non-agricultural uses are also reported. Non-agricultural uses include:

applications to forest trees, ornamental turf, post-harvest treatments, landscapes and

structural use applied by commercial applicators. Residential, institutional and livestock

applications are not reported. The chemicals include pesticides, herbicides, fungicides,

plant growth hormones, fertilizers and compounds that may be used as carriers (such as

mineral oil). (Data from Department of Pesticide Regulations database of registered

pesticide use)



Analysis: Using the literature review in Toxnet and EXToxnet, Regional Board staff

reviewed and summarized the general toxicity and environmental fate of each chemical,

although some were missing critical information. Each constituent was rated as either:

Low, medium, high concern or as “???” if there was insufficient information. The rating

applies only to concern for toxicity in dredge material reuse. This rating does not apply

to impacts to water quality or air quality that may occur from application of the chemical.

They basic questions are:

Does it sorb to sediments?

Is it persistent?

Is it toxic?

The rating roughly describes the compounds as follows:

High: Sorbs to sediments, is persistent and is generally toxic.

Medium: Sorbs to sediments at least moderately, may be moderately persistent, may be

selectively toxic (e.g. herbicides)

Low: Does not sorb to sediments, not very persistent in soil, or low general toxicity.

????: Insufficient information

1998 Top 20 Agricultural chemicals used in 5 Delta Counties



5 County Constituent Contra Sac Co Solano San Yolo Delta Rating

rank Costa Joaquin Sum

35 2,4-D, Dimethylamine salt 9,118 18,921 36,367 64,406 Low

51 Acephate 17,857 17,857 Low

42 AlkyArylPoly/oxyethylene/glycol 41,287 41,287 Low

58 Bifenthrin 9,499 9,499 High

56 Bromadiolone 9,802 9,802 ???

36 Calcium hydroxide 60,872 60,872 Low

30 Captan 77,418 77,418 Low

57 Carbaryl 9,748 9,748 Low

39 Chloropicrin 52,953 52,953 Low

22 Chlorothalinol 11,309 47,390 53,144 111,843 Low

13 Chlorpyrifos 23,492 24,625 30,589 75,702 28,766 183,174 Medium

61 Citric acid 7,610 7,610 Low

5 Copper chloride hydroxide 22,862 47,761 410,401 130,932 611,956 Low

64 Copper hydroxide Low

41 Copper oxychloride sulfate 45,871 45,871 Low

8 Copper sulfate 21,303 34,313 148,820 24,050 228,486 Medium

14 Cryolite 26,443 117,555 23,480 167,478 ???

65 Cycocel ???

62 Cyfluthrin 6,697 6,697 High

66 Cyhalothrin High

49 Diazinon 23,442 23,442 Low

21 Dichloropropene 117,390 117,390 Low

7 Disodium Octaborate Tetrahydrate 275,001 275,001 ???

12 Diuron 33,931 23,575 99,457 30,356 187,319 Medium

20 E,E-8,10-Dodecadien-1-ol 119,760 119,760 Low

Appendix D, Delta Dredge Strategy D-8







6 Glyphosate 25,168 92,708 63,005 244,950 122,427 548,258 Medium

43 Imidacloprid 35,266 35,266 High

40 Iprodione 46,236 46,236 Low

34 Laurel Alcohol 67,237 67,237 Low

16 Lime Sulfur 41,827 100,407 142,234 Low

11 Mancozeb 33,055 8,865 101,126 48,173 191,219 Low

26 Maneb 87,897 87,897 Low

4 Metam Sodium 44,459 194,910 36,632 358,121 634,122 Low

3 Methyl bromide 20,370 54,176 722,436 54,790 851,772 Low

19 Metolachlor 84,295 37,733 122,028 Low

10 Mineral Oil 51,406 150,031 201,437 Low

32 Molinate 25,057 43,427 68,484 Low

31 Norflurazon 69,525 69,525 Low

27 Oryzalin 21,590 64,489 86,079 Low

17 Paraquat dichloride 19,652 17,847 69,830 22,697 130,026 High

44 Pebulate 9,718 24,940 34,658 Low

67 Permethrin Medium

9 Petroleum Distillates 28,200 185,793 213,993

60 Petroleum hydrocarbons 8,470 8,470

2 Petroleum Oil, Unclassified 728,218 67,988 816,615 103,551 1,716,372

52 Phorate 16,804 16,804 Low

37 Phosmet 18,856 39,637 58,493 Low

48 Piperonyl butoxide 29,512 29,512 Low

23 Poly-1-para-menthene 14,771 58,717 35,570 109,058 ???

38 Potash soap 58,042 58,042 Low

33 Propanil 36,196 31,199 67,395 Low

15 Propargite 12,961 132,533 145,494 ???

50 Propetamphos 23,172 23,172 High

25 Propylene oxide 63,347 26,151 89,498 Low

54 Pyrethrins 10,488 10,488 ???

Appendix D, Delta Dredge Strategy D-9







24 Simazine 98,678 98,678 Low

28 Sodium Tetrathiocarbonate 80,765 80,765 Low

45 Sulfometuron methyl 34,400 34,400 Low

1 Sulfur 58,378 2,513,706 842,213 9,269,039 1,556,793 14,240,129 ???

55 Tetrahydro-5,5-dimethyl-2(1H)pyrimidinone 10,033 10,033 Low

46 Thiobencarb 32,153 32,153 Low

63 Thiophanate-methyl 5,856 5,856 High

53 Triclopyr, botoxyethyl ester 15,097 15,097 Low

47 Triflumizole 31,743 31,743 Low

18 Trifluralin 12,501 58,068 53,529 124,098 Low

59 Triforine 9,403 9,403 Low

29 Ziram 78,984 78,984 Medium

Pesticide Environmental Fates / Toxicity

Acephate (Low):

1. Use/source: Organophosphorus Insecticide

2. Soil: Acephate has very high mobility and will readily leach in the soil. If

released to the soil, acephate will degrade by microbial degradation and aqueous

hydrolysis. The rate of hydrolysis increases with increasing pH. The average soil

half-life is about 3 days. A laboratory study of rice paddy soil found a half-life of

3-4 days in aerobic conditions and 13-14 days in anaerobic condition.

3. Water: If released to the water, acephate will degrade by microbial degradation

and aqueous hydrolysis. The rate of hydrolysis increases with increasing pH.

Aquatic volatilization, bioconcentration, direct photolysis and absorption to

sediment are not expected to be important environmental fate processes.

4. Atmosphere: Acephate can exist in both the vapor and particulate phases of the

atmosphere. Vapor-phase phorate is degraded in the atmosphere by reactions

with photochemically produced hydroxyl radicals, with an estimated half-life of 6

hours. Physical removal from the atmosphere may occur through wet or dry

deposition.

5. Toxicity: Acephate is a potent cholinesterase enzyme inhibitor. Acephate is a

possible human carcinogen. The toxic effect may include abdominal cramps,

nausea, vomiting, eye changes, hypotension or hypertension due to asphyxia, and

muscular twitching of the eyelids, tongue, face and neck, possible progressing to

convulsions. Central nervous symptoms include restlessness, anxiety, tremor,

confusion and coma. Death usually occurs from the depression of the respiratory

or cardiovascular system.



Bifenthrin (High):

1. Use/source: Synthetic Pyrethroid Insecticide

2. Soil: Bifenthrin is immobile in soils with large amounts of organic matter, clay or

silt. It has low mobility in sandy soils or soils that are low in organic matter. It

has an estimated half-life in soil ranging from 7 days to 8 months, depending on

the soil type and the amount of air in the soil. Plants do not absorb Bifenthrin and

it does not translocate in the plant. The compound is photostable.

3. Water: Bifenthrin is relatively insoluble in water, stable to hydrolysis and has

minimal volatility.

4. Atmospheric:

5. Toxicity: Synthetic pyrethroids are neuropoisons acting on the axons in the

peripheral and central nervous systems by interacting with cation channels in

mammals and/or insects. A single dose produces toxic signs in mammals, such as

tremors, hyperexcitability, choreoathetosis and paralysis. At near lethal doses it

causes transient changes in the nervous system, such as axonal swelling and/or

breaks and myelin degradation in sciatic nerves.

Appendix D, Delta Dredge Strategy D-11









Bromadiolone (???):



1. Use/source: Anticoagulant Rodenticide (typically used in pellet form indoors or

near structures. Not broadcast or sprayed.)

2. Soil:

3. Water:

4. Atmosphere:

5. Toxicity: Interferes with the production of prothrombin in the liver and hence the

clotting time of the blood is prolonged. The usual mode of death is

gastrointestinal hemorrhage. The EPA classifies bromadiolone as a being on the

List B. This means that this rodenticide is of great concern. The half-life in the

body varies with the amount of toxin. For a dose of 0.8 mg/kg it took 25.7 hours

and 57.5 hours for 3.0 mg/kg. Kidney was slightly higher than those observed in

plasma.



Calcium Hydroxide (Low):

1. Use/source: Soil amendment

2. Soil: Calcium hydroxide is neutralized by absorption of atmospheric carbon

dioxide.

3. Water: May cause toxicity due to pH changes.

4. Atmosphere:

5. Toxicity: Acute poisoning of ingested calcium hydroxide includes vomiting,

diarrhea, severe abdominal pain, and rapid fall in blood pressure. Calcium

hydroxide may cause severe burns to the eyes. This compound shows no

bioaccumulation or food chain concentration toxicity potential.



Captan (Low):

1. Uses/Sources: Fungicide used on fruits and vegetables

2. Soil: Volatilization is probably the most significant loss pathway for Captan in

soil, although degradation by hydrolysis may also be significant in moist soils.

Captan is “not expected to leach extensively” based on a Koc value of 196. The

half-life for Captan in moist soil is estimated at 1-12 days.

3. Water: Captan will have a moderate tendency to sorb to suspended solids and

sediments. The primary degradation route will be hydrolysis, with an expected

half-life of hours. Volatilization may be significant in rivers and streams.

Bioconcentration in aquatic life is low to medium.

4. Air: Captan may exist in the vapor phase or adsorbed to particulate matter in the

atmosphere. Vapor phase Captan will be degraded rapidly by reacting with

hydroxyl radicals, with an estimated vapor phase half-life of 1 hour.

5. Toxicity: Dermal exposure may cause skin irritation. Acute oral exposure of

large amounts of Captan may cause vomiting and diarrhea.

Appendix D, Delta Dredge Strategy D-12





Carbaryl (Low):

1. Use/source: Insecticide/Pesticide

2. Soil: With a Koc of 261, carbaryl has moderate mobility in soils. Volatilization

from moist and dry soils is not expected. Carbaryl is expected to slowly

photolyse on surface soils. Degradation by hydrolysis is slow in acidic soils and

rapid in neutral and alkaline soils (Hydrolysis half-life at pH 7= 10.8 days, half-

life at pH 8= 1.8 days). Biodegradation is expected to be a significant pathway

for carbaryl in the soil. Field tests of acclimated soils showed 80% degradation of

carbaryl within 4 weeks.

3. Water: Carbaryl is not expected to absorb to sediment and suspended solids in the

water. Volatilization, from water surfaces, is not expected. The potential for

bioconcentration is low. Photolysis half-lives calculated from sunlight intensity

data and experimentally determined a range from 52 to 264 hours for a summer

day at latitude 40 degrees North.

4. Atmosphere: Carbaryl is expected to exist in both the vapor and particulate

phases in the ambient atmosphere. The half-life for the reaction of carbaryl with

photochemically produced hydroxyl radicals is 15 hours.

5. Toxicity: Carbaryl particularly affects the central nervous system. Symptoms of

carbaryl poisoning include vomiting, excessive salivation, and weakness, blurring

vision, loss of muscle contraction, convulsions, and coma. Death is primarily

caused by respiratory arrest.



Chloropicrin (Low):

1. Uses/Sources: Soil sterilant, fumigant for grain and cereal storage, fungicide, by-

product of water and wastewater treatment.

2. Soil: When introduced to the soil, chloropicrin will rapidly volatilize or leach. It

is not expected to stay sorbed to the soil.

3. Water: Although chloropicrin in the water column is highly soluble, it is expected

to rapidly volatilize. The expected half-life varies from 4 hours to 5 days,

depending on conditions. Photolysis may occur in surface waters, with an

expected half-life of 3 days. Chloropicrin will not sorb to sediments or

bioconcentrate.

4. Air: If released to the atmosphere, chloropicrin will degrade largely by

photolysis, with an expected half-life of 20 days. Degradation by reacting with

hydroxyl radicals is substantially slower with an expected half-life of 123 days.

Since chloropicrin is highly soluble, it may partition into atmospheric water and

be washed out by rain.

5. Toxicity: Chloropicrin is extremely irritating to the skin, eyes, mucous

membranes and respiratory tract. Exposure from ingestion can cause nausea,

vomiting, colic and diarrhea. Exposure from inhalation can cause lacrimation,

anemia, weak & irregular heart, asthmatic attacks, pulmonary edema, coma,

hepatic necrosis.

Appendix D, Delta Dredge Strategy D-13





Chlorothalinol (Low):

1. Uses/Sources: fungicide, wood preservative, paint additive

2. Soil: Sorbs to soil (Koc = 1,800) but may have some mobility and leaching.

Biodegrades with an expected half-life of 30 days. Biodegradation products are

chlorinated phthalonitriles.

3. Water: Chlorothalinol is expected to biodegrade water with a half-life of 0.2 to 8

days. Significant adsorption to sediment is also likely. The calculated BCF is

820, indicating that bioconcentration in aquatic organisms may occur.

Chlorothalinol is not expected to volatilize.

4. Atmosphere: Chlorothalinol may exist in the atmosphere in both vapor phase and

particulate phase. Vapor phase degradation may occur by both photolysis and

reaction with hydroxyl radicals, however the hydroxyl radical reaction is quite

slow (half-life of 7 years). Particulate phase chlorothalinol is generally removed

from the atmosphere by wet or dry deposition.

5. Toxicity: Dermal exposure resulted in acute dermatitis in some farm workers.

LD50 in rats is greater than 10 g/kg of body weight. Not classifiable as a

carcinogen.



Chlorpyrifos (Dursban) (Medium):

1. Type: Organophosphate Insecticide

2. Soil: Chlorpyrifos has very low to no mobility in soil and is not expected to

leach. Volatilization is not expected to occur in dry soils but may be an important

fate for moist soils (half-life of 46 to 163 hours). The half-life of chlorpyrifos

depends on soil type and ranges from 81 days for sandy soil to 1.6 to 25 days for

soils with higher clay content.

3. Water: The main fate of chlorpyrifos in the water column is partitioning into

other environmental media by adsorption, volatilization and bioconcentration.

Degradation by hydrolysis may occur to a minor extent with a hydrolysis half-life

of 24 days. Volatilization half-life is estimated at 16 days in a river environment.

BCF values measured in fish are high, ranging from 100-4,667.

4. Atmosphere: Chlorpyrifos exists in both vapor phase and particulate phase in the

atmosphere. The vapor phase will rapidly degrade (half-life of 4 hours) by a

reacting with hydroxyl radicals. The particulate phase will be removed by wet or

dry deposition. The half-life of thin film deposition of chlorpyrifos is 52 hours.

5. Toxicity: Chronic exposure can result in inhibition of cholinesterase, with

symptoms that include headache, weakness, memory decline, confusion, and

nervous system disorders. Acute poisonings result in respiratory or

gastrointestinal distress, depending on route of exposure, numerous symptoms of

the central nervous system, immediate or delayed paralysis, and possibly

respiratory and cardiac failure leading to death. Oral LD50 in rats = 145 mg/kg.

6. Uses: Chlorpyrifos is commonly used on crops such as cotton, oranges, almonds,

alfalfa, walnuts, broccoli, sugar beets, cauliflower, apples, and nursery crops.

Appendix D, Delta Dredge Strategy D-14





Citric Acid (Low):

1. Use/source: Citric acid is used as ingredient in food preservatives, pesticides and

as a food additive.

2. Soil:

3. Water:

4. Atmosphere:

5. Toxicity: Frequent or excessive intake of citric acid may cause erosion of teeth

enamel and local irritation. Inhalation of dust irritates nose and throat. Contact

with the eyes causes irritation.



Copper Chloride Hydroxide (Low)

1. Uses/Sources: Fungicide

2. Soil: Alkaline conditions facilitate precipitation of copper compounds, while

acidic conditions can cause increased solubility.

3. Water:

4. Air:

5. Toxicity: Ingestion of copper chloride hydroxide is rarely severe due to its

tendency to cause vomiting. If vomiting does not occur, adsorption of copper

compounds into the body can cause systemic poisoning that has the following

symptoms: capillary damage, kidney and liver damage, central nervous system

excitation followed by depression, jaundice, renal tube injury and possible death

due to renal failure. Copper is highly toxic to aquatic organisms. Chronic

poisoning of sheep has occurred when sheep graze in orchards sprayed with

copper compounds, with deaths occurring with food intake concentrations as low

as 9 ppm.



Copper (II) Hydroxide (Low):

1. Use/source: Fungicide

2. Soil: Alkaline conditions in the soil favor precipitation of copper. Acid

conditions promote solubility of copper, increasing the concern of ionic copper,

and thereby change the microorganisms, depending on tolerance for various levels

of copper in solution.

3. Water: Alkaline conditions in the surface water favor precipitation of copper.

Acid conditions promote solubility of copper, increasing the concern of ionic

copper, and thereby change aquatic populations, depending on tolerance for

various levels of copper in solution.

4. Atmosphere:

5. Toxicity: In general the soluble ionized salts of copper are much more toxic than

the insoluble or slightly dissociated compounds. Toxic effects of copper include

widespread capillary damage, kidney and liver injury, and central nervous

excitation followed by depression. Jaundice and pain over the liver have been

reported in acute human poisonings. Hemolytic anemias are also described in

acute poisonings. Circulatory shock and intravascular hemolysis, single or

together, may lead to renal tubular injury and death in renal failure. On the skin,

copper salts also act as irritants producing itching eczema; and on the eye,

conjunctivitis, or even ulceration and turbidity of the cornea.

Appendix D, Delta Dredge Strategy D-15







Copper oxychloride sulfate (Low):

1. Use/source: Fungicide, Bactericide

2. Soil: The efficacy of copper can be improved by adding oil to spray mixture of

chemicals.

3. Water: Copper ion is relatively insoluble and less phytotoxic compared to copper

sulfate.

4. Atmosphere:

5. Toxicity: Target organs are the respiratory tract, the skin, the liver and kidneys.

Symptoms include irritations of the eyes, nose and throat, central nervous system

degeneration, immune system damage, tremors, stomach cramps and death.



Copper (II) Sulfate, Pentahydrate (Medium)

1. Type: Pesticide (esp. algae, tadpole shrimp), Fungicide

2. Soil: Copper sulfate is strongly adsorbed by clay and humus. Copper may also

precipitate as insoluble forms of hydroxides, phosphates or carbonates. Copper is

mobile under acidic conditions. Factors that affect copper solubility include: pH,

oxidation-reduction potential, and amount of organic matter.

3. Water: Generally sorbs to sediment or precipitates, depending on pH, hardness

and presence of other constituents. Adsorbed by algae, but excess copper is not

adsorbed by plants.

4. Atmosphere:

5. Toxicity: Highly toxic to aquatic life but relatively low toxicity to humans. If

ingested, may cause vomiting, diarrhea, gastrointestinal ulceration and jaundice.

Acute poisoning may cause renal failure.

6. Uses: Copper sulfate is commonly used on crops such as rice, wild rice, oranges,

cherries, walnuts, almonds, olives, prunes, nursery crops, and is used to control

algae in aquatic areas.



Cryolite (Aluminum Sodium Fluoride) (??)

1. Uses/Sources: insecticide, naturally occurring ore

2. Soil: Aluminum may leach from Aluminum Sodium Fluoride, depending on soil

type and pH.

3. Water: Generally adsorbs to sediment, but adsorption rate is dependent on pH,

particle size and amount of aluminum in particle.

4. Atmosphere:?

5. Toxicity: Chronic sublethal exposures can result in fluorosis, brittle bones, and

anemia. Lethal dose in humans is estimated at 70 to 140 mg/kg body weights. 7-

ppm allowable food residue



Cycocel (???)

1. Uses/Sources: plant growth regulator

2. Soil: Cycocel exists as a cation in the soil and sorbs strongly to ionic sites on the

soil, particularly clays and organic matter. The primary fate is biodegradation.

Half-life is not reported.

Appendix D, Delta Dredge Strategy D-16





3. Water: Due to its positive charge, cycocel is expected to adsorb to sediments and

suspended matter in the water column. Biodegradation may occur and may be

accelerated in nutrient rich waters. Half-life is not reported. Volatilization or

bioconcentration is not expected to occur.

4. Atmosphere: Cycocel can exist in both the vapor phase and particulate phase in

the atmosphere. Vapor phase cycocel may be degraded by reacting with hydroxyl

radicals, with a half-life of 12 days. Particulate phase cycocel may be removed by

wet or dry deposition.

5. Toxicity: Dermal exposure results in contact dermatitis. Exposure by ingestion

can result in tremors, seizures, pulmonary edema, and cardiac fibrillation leading

to death. Lethal doses are generally due to respiratory failure due to

neuromuscular blockage. Oral LD50 for rats is 330-750 mg/kg. Oral LD50 for

mallards is 265 mg/kg.





Cyfluthrin (High):

1. Type: Pyrethroid Insecticide

2. Soil: Cyfluthrin has Koc of 33,800 and has no mobility in the soil. Volatilization

is not expected in moist or dry soils. Biodegradation is an important fate process

for this compound, but the half-life in soil was not reported. Products of

degradation are 3-(2,2-dichlorovinyl) 2,2-dimethylcyclopropancarboxcylic acid

and 4-fluoro-3-phenoxybenzoic acid. Photodegradation may be significant on soil

surfaces.

3. Water: Cyfluthrin is expected to absorb to suspended solids and sediment in

water. It is not expected to volatize from water surfaces. Photolysis is expected

for this compound, with an experimental half-life of 16 hours in solution.

Cyfluthrin is likely to bioconcentrate, since it is structurally similar to

cypermethrin (BCF 400).

4. Atmosphere: Cyfluthrin is expected to exist primarily in the particulate phase in

the atmosphere. Particulate phase cyfluthrin may be physically removed from the

atmosphere by wet and dry deposition.

5. Toxicity: Cyfluthrin is extremely toxic to fish and aquatic organisms, but has low

toxicity to upland game and waterfowl. The LC50 for Rainbow trout is

89ng/L/96hr. Cyfluthrin is a neuropoison that acts on the axons in the peripheral

and central nervous systems, interacting with sodium channels. A single dose

produces toxic signs in mammals, such as tremors, hyperexcitability,

choreoathetosis (sinuous writhing) and paralysis. At near lethal doses it causes

transient changes in the nervous system, such as axonal swelling and/or breaks

and myelin degradation in sciatic nerves. Oral LD50 in rats 500 to 1200 mg/kg.

6. Uses: Cyfluthrin is commonly used on crops such as: corn, alfalfa, carrots, hops,

peppers, radishes, sugarcane, sunflowers, and tomatoes.

Appendix D, Delta Dredge Strategy D-17





Cyhalothrin (High):

1. Type: Pyrethroid Insecticide.

2. Soil: With a measured Koc value of 106,000 to 476,000, leaching of this

compound is not expected to occur. The half-life in the soil is estimated at 4-12

weeks.

3. Water: With a calculated BCF of 16,000, bioconcentration is expected to be

significant. With the high Koc value, Cyhalthrin will also strongly adsorb to

sediment and suspended matter. Cyhalothrin will volatilize slowly in the water

with a calculated half-life 52.7 days in a model river and 400 days in a model

lake.

4. Atmosphere: Cyhalothrin will exist in the vapor and particulate phases in the

atmosphere. Photochemically produced hydroxyl radicals with an estimated half-

life of 7.6 hours. It will also degrade with ozone with a half-life of 7 days.

5. Toxicity: Synthetic pyrethroids are neuropoisons acting on the axons in the

peripheral and central nervous systems by interacting with cation channels in

mammals and/or insects. “A single dose produces toxic signs in mammals, such

as tremors, hyperexcitability, choreoathetosis and paralysis. At near lethal doses

it causes transient changes in the nervous system, such as axonal swelling and/or

breaks and myelin degradation in sciatic nerves.”(Toxnet) Sub-lethal exposures

to cyhalothrin result in suppression of the immune system. Cyhalothrin has been

shown to be toxic to honeybees, fish and aquatic invertebrates.

6. Uses: Cyhalothrin is commonly used on crops such as: apples, pears, and

oranges.



Diazinon (Low)

1. Uses/Sources: Organophosphate pesticide

2. Soil: With Koc values from 40-432, diazinon is likely to leach from the soil.

Degradation by hydrolysis is reported to be slow, but it may still be a significant

pathway in some soils. Microbial degradation is expected to be the major

pathway with a reported half-life ranging from 1 to 5 weeks. Photolysis may also

be important on soil surfaces.

3. Water: Hydrolysis is an important degradation pathway for diazinon in water,

with a reported half-life of 185 days at pH 7.4. Adsorption to sediments may also

occur to a limited extent. Volatilization may be significant in flowing rivers, with

an estimated half-life of 46 days in a river of 1-meter depth. Diazinon is not

expected to bioconcentrate.

4. Air: Diazinon in the vapor phase degrades rapidly by reacting with hydroxyl

radicals (expected half-life of 4.8 hours). Degradation by photolysis may also be

significant.

5. Toxicity: Diazinon inhibits the acetylcholinesterase function at synaptic nerve

junctions. Symptoms of light exposure in humans include salivation, headache,

blurred vision, vomiting and contact dermatitis. Higher levels of toxicity in

mammals include symptoms of defecation, urination, weakness, abdominal pain,

and muscle twitching. Serious toxicity symptoms include convulsions,

respiratory failure, and cardiac arrhythmia possibly leading to death. Diazinon is

Appendix D, Delta Dredge Strategy D-18





highly toxic to fish and aquatic life at low concentrations. Oral LD50 in rats is

300-400 mg/kg. Acute oral LD50 in adult Northern bobwhites is 10 mg/kg.



Dichloropropene (Low):

1. Uses/Sources: Soil fumigant

2. Soil: If dichloropropene is released into the soil, it will volatilize into the

atmosphere over a period of a couple weeks. Dichloropropene may also leach

into groundwater. Dichloropropene may biodegrade or degrade by hydrolysis in

moist soils, but reaction rates are not known.

3. Water: Most dichloropropene released into the water will volatilize.

Bioconcentration in fish is not significant.

4. Air: Dichloropropene degrades fairly rapidly in the atmosphere by reacting with

hydroxyl radicals. The half-life ranges from 14 hours to 6 days, depending on the

isomer.

5. Toxicity: Dermal exposure results in severe irritation and inflammation of skin

and underlying tissues. Symptoms from inhalation exposure include gasping,

coughing, chest pain, extreme respiratory distress leading, headache, and

lacrimation, possibly leading to coma. Exposure by ingestion can lead to

gastrointestinal distress, pulmonary congestion and edema, central nervous system

depression, damage to liver, kidneys and heart. Subchronic acute exposures have

led to symptoms that persist for months to years.



2,4-D, Dimethylamine (Low)

1. Uses/Sources: broadleaf herbicide

2. Soil: The expected half-life in soil is 4-23 days, depending on temperature.

Leaching of 2,4-D has been shown in some field studies.

3. Water: In the water column, 2,4-D, dimethylamine is primarily removed by

microbial degradation with measure half-life of 0.5 to 11 days. Volatilization,

adsorption and bioconcentration are not significant.

4. Air: 2,4-D, dimethylamine may exist as an aerosol or in the vapor phase.

Aerosols will be subject to gravitational settling. The vapor phase may be

degraded by reacting with hydroxyl radicals, with an expected half-life of 24

hours.

5. Toxicity: Can be adsorbed dermally, orally or by inhalation. Acute eye and skin

irritation results from dermal and inhalation exposure. If ingested the following

symptoms may occur: vomiting, congestion, pulmonary emphysema, CNS

depression, muscle twitching, fever, perivascular hemorrhages, degeneration of

ganglion cells, convulsions, coma, and death. 2,4-D, dimethylamine is classified

as a possible human carcinogen based on some findings of increased incidence in

soft-tissue sarcomas in exposed populations. LC50 largemouth bass 350 mg/l.



Disodium octaborate tetrahydrate (???):

1. Uses/source: Disodium octaborate tetrahydrate is a soluble borate salt that is used

as a wood preservative, fungicide, and protection against wood boring insets.

2. Soil: Depending on soil type, borax can persist for 1 or more years. Finer

textured soils retain the boron longer than do coarse, sandy soils. Boron sorption

Appendix D, Delta Dredge Strategy D-19





by clay minerals, iron and aluminium oxides is pH dependent, with maximum

sorption in the range 7-9. The more acidic and wet the environment the less the

borax will stay combined with the soil. Leaching is a problem under high rainfall

conditions.

3. Water: Disodium octaborate tetrahydrate is highly soluble in water.

4. Atmosphere:

5. Toxicity: Toxic and accumulates in plants. Symptoms of acute borax respiratory

irritation include dry mouth, nose, or throat, dry cough, nose bleeds, shortness of

breath and chest tightness. Also symptoms form ingesting borax include nausea,

vomiting, diarrhea, headaches, tremors and convulsions with central nervous

system depression. Death is due to vascular collapse in the early stages or to CNS

depression in the later stages. The highest concentrations of borax are reached

during excretion; the kidneys are more seriously damaged than other organs.



Diuron (Medium)

1. Type: Pre-Emergent Herbicide

2. Soil: Diuron is strongly adsorbed to soil, and has not been found to leach beyond

the upper 10 cm, regardless of soil type or amount of water applied.

Volatilization is not expected to occur. Biodegradation occurs slowly, with a

half-life of approximately 330 days, although it varies depending on initial

concentration, soil type and temperature. Phytotoxic effects may persist for more

than one season. The major byproduct of degradation was 3(3,4-dichlorophenyl)-

1,1-dimethylurea.

3. Water: In clear surface water, photolysis may contribute to degradation of

Diuron, but the main fate is likely to be adsorption to sediments. Organic rich

sediments with moderate temperatures showed 90% degradation in 8 months.

Diuron shows only minor bioconcentration amounts in aquatic life.

4. Atmosphere: Due to its low vapor pressure, Diuron is not likely to be found in

volatile form.

5. Toxicity: The oral LD50 in rats is reported as 437 mg/kg. Diruon may irritate

eyes, nose, throat and skin.

6. Uses: Diuron may be used for weed control in crops such as: asparagus, alfalfa,

corn, peas, apples, artichokes, citrus fruits, grapes, olives, potatoes, and

sugarcane.



(E, E)-8,10-dodecadien-ol (Low):



1. Uses/source: Codling moth pheromone

2. Soil:

3. Water:

4. Atmosphere:

5. Toxicity: This compound is used to disrupt mating by disrupting the male moth’s

mate-finding abilities.

Appendix D, Delta Dredge Strategy D-20







Glyphosate (Medium)

1. Type: Non-Selective Herbicide

2. Soil: Glyphosate stays strongly adsorbed to soil and is unlikely to leach.

Average soil half-life is 45 to 60 days, although field residues (6-18% of original

concentration) have often been found a year after spraying. Glyphosate

undergoes biodegradation under aerobic and anaerobic conditions. The half-life

varies from 3 to 130 days, depending on the soil conditions.

3. Water: The half-life in water is only a few days due to the strong tendency to

sorb to sediments. After spraying glyphosate levels in the sediment rise and then

level off to low levels after a few months.

4. Air: Glyphosate is removed from the air by gravitational settling onto soil or

water.

5. Toxicity: Routes of exposure include ingestion, dermal contact and inhalation.

Generally low human toxicity, although fatalities have occurred from ingestion of

large amounts of Roundup. Toxicity: oral LD50 in rats= 1568 mg/kg

6. Uses: Glyphosphate is used for weed control in crops such as: almonds, cotton,

oranges, grapes, tomatoes, walnuts, lemons, nursery crops, and uncultivated

agriculture areas.



Hydramethylnon (Low): (Tetrahydor-5, 5-dimethyl-2 (1H) pyrimidinone):

1. Use/source: Slow-acting insecticide for ants (big headed, fire, harvester), and

cockroaches.

2. Soil: Wit a measured Koc of 430, hydramethylnon is expected to have moderate

mobility in the soil. Volatilization for dry soils is not anticipated, but

volatilization for moist soils may be important. The half-life of Hydramethylnon

is sandy loam soil is 7 to 28 days. This chemical is not expected to undergo

hydrolysis in the environment due to the lack of hydrolysable functional groups.

3. Water: Hydramethylnon is not likely to absorb to suspended solids and sediment

in the water. Photolysis in aqueous media at various pH values result in 80 to 94

percent transformation within 10 hours. This chemical may volatilize from water.

The estimated volatilization half-life for a model river and model lake is 37 days

and 278 days, respectively. With a calculated BCF of 36, bioconcentration of

this chemical is expected to be moderate.

4. Atmosphere: Hydramethylnon exists primarily in the particulate phase in the

atmosphere. Particulate-phase hydramethylnon may be physically removed from

the air by wet and dry deposition. Any vapor-phase hydramethylnon is degraded

in the atmosphere by reaction with hydroxyl radicals (half-life of 2.7 hours) or by

photolysis (half-life of 1 hour).

5. Toxicity: ???



Imidacloprid (High):

1. Type: Insecticide (selective for sucking insects)

2. Soil: The half-life of Imidacloprid in the soil is 48-190 days, with faster

degradation in soils with plant cover than in fallow soils. Imidacloprid is

moderately soluble and has moderate binding affinity to organic materials in soils.

Appendix D, Delta Dredge Strategy D-21





There is potential for the compound to leach in porous, gravely or cobbly soils,

depending on irrigation practices.

3. Water: The half-life in water is much greater than 31 days at pH 5,7 and 9.

4. Atmosphere:

5. Toxicity: Imidacloprid causes a blockage in a type of neuronal pathway

(nicotinergic) that is more abundant in insects than in warm-blooded animals.

This blockage leads to the accumulation of acetylcholine resulting in the insect’s

paralysis, and eventually death. Imidacloprid is mildly mutagenic. Studies of the

reproductive effects in animals resulted in decreased pup body weight and skeletal

abnormalities. Imidacloprid is considered to be of minimal carcinogenic risk.

This compound is quickly and almost completely absorbed form the

gastrointestinal tract and eliminated via urine and feces. Imidacloprid is highly

toxic to bees and aquatic invertebrates. It is toxic to upland birds and moderately

toxic to fish. Imidacloprid can be toxic to plants. The oral LD50 in bob-white

quail is 152 mg/kg. The LC50 for rainbow trout is 211 mg/l and for Daphnia, 85

mg/l.

6. Uses: Imidacloprid is a selective insecticide used to control sucking insects in

crops such as: cotton, lettuce, grapes, broccoli, cantaloupe, cauliflower, cabbage,

and nursery crops.



Iprodione (Low)

1. Uses/Sources: Fungicide

2. Soil: Iprodione has an estimated Koc of 700 and so is not expected to leach. In

the soil, iprodione degrades by microbial degradation and hydrolysis. The USDA

reports and estimated half-life of 14 days in soil, but it can vary from 2 days in

acclimated soils to 35 days in non-acclimated soils.

3. Water: In water, iprodione would be expected to adsorb to sediments based on

the high Koc values. Iprodione on the moist sediment and remaining in the water

column could biodegrade or degrade by hydrolysis. The hydrolysis half-life

varies with temperature and pH but is estimated at 1.1 days at 25oC and pH 7.

4. Air: In the air, vapor phase iprodione will degrade rapidly by reacting with

hydroxyl radicals, with an expected half-life of 8 hours. Iprodione in aerosols or

particulate phase may be removed by wet or dry deposition.

5. Toxicity: Low toxicity to mammals and waterfowl, but may be more toxic to

aquatic life. Neither phytotoxic nor toxic to bees. Oral LD50 for rats is 3500

mg/kg. The LC50 for rainbow trout is 6.7 mg/l/96 hours. Chronic sublethal

exposures in rats resulted in decreased prostrate weight in males and decreased

uterus weight in females.



Mancozeb (Low)

1. Uses/Sources: Fungicide (carbamate)

2. Soil: Mancozeb has low mobility in soils and is not expected to significantly

leach or volatilize. Biodegradation and hydrolysis are the most important

degradation mechanisms in soil. Biodegradation half-life estimates range from 2

days to 40 days, depending on oxygen availability, soil moisture and soil type.

Appendix D, Delta Dredge Strategy D-22





3. Water: Mancozeb is expected to adsorb to sediments or particulate matter in the

water column. Hydrolysis may be an important degradation mechanism with a

hydrolysis half-life of 2.3 days at pH 7.

4. Atmosphere: Mancozeb is expected to exist only in the particulate phase in the

atmosphere and may be removed by wet or dry deposition.

5. Toxicity: May cause skin irritation or dermatitis. Chronic exposure has shown

evidence of chromosomal damage. A degradation product, ethylene thiourea, is a

known mutagen, teratogen and carcinogen.



Maneb (low)

1. Uses/Sources: broad-spectrum fungicide

2. Soil: Koc values indicate that Maneb may be moderately mobile but field studies

have shown it to be large immobile with no residues found below a 5-inch depth.

Maneb is not expected to volatilize from the soil. Maneb degrades both

abiotically and biotically with field-derived half-lives ranging from 6 to 36 days.

3. Water: Maneb degrades rapidly in water by multiple mechanisms with and

expected half-life of less than 1 day, although it varies based on aeration and pH.

Volatilization is not considered important from the water column. Sorption to

sediment may be significant.

4. Atmosphere: Maneb exists only in the particulate phase in the atmosphere, where

it would be removed by wet or dry deposition.

5. Toxicity: Maneb is generally considered harmless except for mild irritation of

skin, eyes or upper respiratory tract. However, one acute exposure reported

symptoms of renal failure and ECG abnormalities.



Metam Sodium (Sodium Methyldithiocarbamate) (Low)

1. Uses/sources: Soil fumigant

Although metam sodium is a relatively non-toxic eye and skin irritant, its major

decomposition product methyl isothiocyanate is highly toxic.

2. Soil: Metam sodium rapidly degrades within 1-5 hours into a volatile form of

methyl isothiocyanate. The vapor form of MITC is highly toxic (methyl mustard

gas).

3. Water: Metam sodium oxidizes into MITC with a half-life of 12-15 hours.

Neither metam sodium nor MITC sorbs to soil. MITC is highly toxic to aquatic

life.

4. Air: The fate of metam sodium released to air is surface deposition to soil or

water. MITC vapors degrade by photolysis in the air.

5. Toxicity: Metam sodium degradation product is highly toxic by inhalation,

ingestion or dermal exposure.



Methyl Bromide: (Low)

1. Use/sources: Soil fumigant, auto exhaust

2. Soil: If applied to soil, the primary route of loss is volatilization, although some

leaching may occur. Methyl bromide does not sorb to soil. This compound may

biodegrade or decompose by hydrolysis to methanol and bromide ions.

Appendix D, Delta Dredge Strategy D-23





3. Water: The primary fate of methyl bromide is volatilization, although some

degradation by hydrolysis may occur (half-life 20-26 days).

4. Air: Major route of exposure for methyl bromide is concentrations in the air.

Photochemical degradation occurs in the atmosphere with half-life range from

0.29 years to 1.6 years, depending on the temperature and concentration of

hydroxyl radicals.

5. Toxicity:



Metolachlor (Low)

1. Uses/Sources: Herbicide

2. Soil: Metolachlor biodegrades in soil with an expected half-life of 56 days.

Metolachlor adsorbs weakly to soil so the potential for leaching is high. On soil

surfaces, some metalochlor may be degraded by photolysis. Volatilization may

also occur depending on temperature and wind speed. Based on soil

characteristics and climate conditions, the half-life of metolachlor in soil may

range from 11 days to 180 days.

3. Water: In water, metolachlor may degrade by hydrolysis, photolysis and

biodegradation. Sorption, volatilization and bioconcentration are not important

fates for metolachlor in the water column. The hydrolysis half-life of metolachlor

in water is 210 days. However, metolachlor degradation in ground water is

considerably slower with measured half-lives ranging from 548 to 1074 days.

4. Atmosphere: Metolachlor degrades rapidly in the air due to a reaction with

hydroxyl radicals. The expected half-life is 1.8 hours.

5. Toxicity: Dermal exposure can result in skin and eye irritation, and corneal

opacity. Acute exposure via ingestion has the following symptoms: abdominal

cramps, anemia, hypothermia, collapse, convulsions, diarrhea, vomiting, GI tract

irritation, liver damage, CNS depression, and cardiovascular failure. NOAEL

13.7 mg/kg. Oral LD50 in rats = 2,780 mg/kg.





Molinate (Low)

1. Uses/Sources: Herbicide (commonly used on rice)

2. Soil: If Molinate is applied to flooded soil, volatilization rapidly occurs resulting

in a half-life ranging from 1 to 6 days. If the soil is not flooded, microbial

degradation and volatilization are both major pathways, resulting in a chemical

half-life of 14 to 35 days. Anaerobic conditions retard the rate of microbial

degradation. Koc values range from 80-89, and molinate has been found to leach

in some cases.

3. Water: Due to the low Koc values, adsorption is minor. Volatilization may be a

major fate of molinate in the water, especially in the warm, shallow waters of

flooded rice fields. Molinate can also degrade in water through biodegradation

and photooxidation. The half-life of molinate in water from rice fields ranged

from 0.6 to 6.6 days.

4. Atmosphere: Molinate may exist in vapor phase or as an aerosol. Aerosols may

be removed from the air by wet or dry deposition. The vapor phase will rapidly

Appendix D, Delta Dredge Strategy D-24





degrade by reacting with hydroxyl radicals, with an expected half-life of 12.7

hours.

5. Toxicity: Routes of exposure include dermal contact, inhalation of aerosols and

dust, and ingestion of contaminated water. Acute symptoms from ingestion

include nausea, diarrhea, abdominal pain, and fever. Dermal exposure may cause

irritation to skin and eyes. Inhalation exposure may lead to systemic poisoning.

Concentrations of molinate as low as 29 ppb can cause blood coagulation and

anemia in fish, leading to death. Oral LD50 in rats = 450 mg/kg body weight.



Norflurazon (Low)

1. Uses/Sources: Herbicide

2. Soil: With an estimated Koc value of 698, Norflurazon is considered to be largely

immobile in soil. The main route of degradation is microbial degradation with an

estimated half-life between 30 and 92 days. Volatilization and photolysis may be

important at the soil surface.

3. Water: Norflurazon would somewhat adsorb to suspended solids and sediments,

but is not expected to volatilize. Biodegradation would also be a major

mechanism in water. Bioconcentration would not be significant.

4. Air: Norflurazon can exist in both the vapor phase and particulate phase in the

atmosphere. Vapor phase degradation occurs rapidly by reacting with hydroxyl

radicals with and estimated half-life of 5 hours. Particulate phase norflurazon

may be removed by wet or dry deposition.

5. Toxicity: No teratogenic, mutagenic or reproductive effects were found in long-

term studies on rats. Oral LD50 for rats: >8000 mg/kg.



Omite (Propargite) (???)

1. Uses/Sources: Insecticide to control mites (acaricide)

2. Soil: Omite sorbs strongly to soil and is considered slightly mobile to immobile

based on Koc values of 2300 and 7800. No studies have been done to determine

degradation rates in natural soil, although omite in composted cotton waste had a

degradation half-life of about 30 days under both aerobic and anaerobic

conditions.

3. Water: Omite in the water column would volatilize or sorb to sediments. No

degradation mechanisms in water are known. Omite could potentially

bioconcentrate, based on calculations.

4. Atmosphere: Omite would exist in the vapor phase in the air, but would rapidly

degrade (half-life of 4.9 hours) by reacting with hydroxyl radicals.

5. Toxicity: Agricultural workers have reported dermatitis and eye irritation from

exposure to omite residues.



Oryzalin (Low)

1. Uses/Sources: Pre-emergent herbicide

2. Soil: Koc values from 75 to 150 indicate that oryzalin may potentially leach, but

field studies have shown it to be largely immobile. Laboratory studies have

shown the soil half-life to range from 1 to 4 months under aerobic conditions and

Appendix D, Delta Dredge Strategy D-25





10 days under anaerobic conditions. Field studies indicate that oryzalin has a

half-life of 15 to 40 days.

3. Water: Oryzalin may degrade in water via similar mechanisms as soil

degradation, but the half-life is not known. Based on theoretical calculations,

adsorption, volatilization and bioconcentration are not considered important.

4. Atmosphere: Oryzalin can exist in both the vapor phase and particulate phase in

the atmosphere. Vapor phase degradation occurs rapidly by reacting with

hydroxyl radicals with and estimated half-life of 3.7 hours. Particulate phase

oryzalin may be removed by wet or dry deposition.

5. Toxicity: Listed as a possible human carcinogen based on limited evidence in

animal studies. Oryzalin can be irritating to skin, eyes and mucous membranes.



Paraquat (High)

1. Type: Herbicide

2. Soil: Paraquat is immobile in soil with Koc values of 15,000 to 1,000,000.

Although there is evidence that microbes degrade Paraquat, often it is bound so

tightly to clay and humic particles that it is not bioavailable. However, the

paraquat may eventually be displaced from its binding sites by the presence of

other ions (K+, Ca2+, or Na+) One-field study showed the half-life of Paraquat in a

field soil to be 6.6 years. Biodegradation depends on soil type, especially clay

and organic matter content.

3. Water: If released to water, paraquat will be completely removed from the water

in 8-12 days due to adsorption to suspended solids and sediment. Paraquat is not

expected to bioconcentrate in aquatic organisms.

4. Atmosphere: Paraquat is expected to exist in the particulate phase in the

atmosphere, where it will be removed by wet or dry deposition.

5. Toxicity: Possible human carcinogen. Acute exposure from ingestion causes

liver and kidney damage, respiratory distress and development of progressive

pulmonary fibrosis leading to death. If splashed into the eyes, paraquat can cause

corneal scarring. Sublethal dermal exposure can cause irritation of the skin and

mucous membranes. The lethal dose for humans is 35 mg/kg of body weight.

6. Uses: More than half the use of paraquat dichloride in California is on cotton

crops, but it has also been used on crops such as almonds, grapes, alfalfa, peaches,

walnuts, nectarines, tomatoes, and plums.



Pebulate (Low)

1. Uses/Sources: Herbicide

2. Soil: With Koc values ranging from 427 to 719, pebulate has low to moderate

mobility in soil. Field studies have shown that the herbicide is not likely to leach

beyond the top 10 cm of soil. The major route of removal of Pebulate from soil is

microbial degradation. The expected half-life of pebulate applied to the surface

of dry soil is 14 days.

3. Water: When pebulate is released to water, volatilization may be a major

pathway of removal although it may not be rapid. Pebulate is resistant to

degradation by chemical hydrolysis. It is not expected to significantly sorb to

sediments or bioconcentrate.

Appendix D, Delta Dredge Strategy D-26





4. Air: Pebulate will exist primarily in the vapor phase and will degrade rapidly by

reacting with hydroxyl radicals. The expected half-life is 13.5 hours.

Degradation by photolysis may also occur.

5. Toxicity: Pebulate may be irritating to the eyes. Pebulate caused decreased

productivity of plankton community at 1 ppm. Oral LD50 for rats is 921-1120

mg/kg. LC50 for Mosquito fish is 10 ppm/96 hours.



Permethrin (Medium):

1. Type: Pyrethroid Insecticide

2. Soil: With a Koc of 63,000, permethrin will strongly adsorb to the soil and not

leach. In aerobic soil, the estimated half-life of this compound is less than 30

days. Under anaerobic conditions, degradation half-life has been measured at 32

to 64 days, depending on the isomer present. Photolysis may occur on the surface

of the soil, with an estimated half-life in sunlight of 5-17 days at pH 9.

Hydrolysis in alkaline moist soils may contribute to the removal of permethrin

from soil.

3. Water: Permethrin will adsorb from the water column to sediment and suspended

solids. With a bioconcentration factor of 480 in minnows and 1,900 in oysters

indicates that bioconcentration may be an important factor. Biodegradation and

photolysis in near-surface waters exposed to sunlight may be important processes

in water. Volatilization is not important for this compound.

4. Atmosphere: This compound will primarily exist in the particulate-phase of the

atmosphere. The half-lives for photochemically produced hydroxyl radicals have

been estimated to be 9.9 hours. The photodegredation half-lives are 5-17 days.

5. Toxicity: “Synthetic pyrethroids are neuropoisons acting on the axons in the

peripheral and central nervous systems by interacting with cation channels in

mammals and/or insects. A single dose produces toxic signs in mammals, such as

tremors, hyperexcitability, choreoathetosis and paralysis. At near lethal doses it

causes transient changes in the nervous system, such as axonal swelling and/or

breaks and myelin degradation in sciatic nerves.”(Toxnet) Permethrin has no

carcinogenic, reproductive, mutagenic or teratogenic effects. The oral LD50 in

rats is 430 mg/kg to 1.3 g/kg. Permethrin is highly toxic to fish, with an LC50 for

rainbow trout equal to 5.4 ug/l.

6. Uses: More than half the permethrin use is on lettuce crops, but it has also been

used for insect control in crops such as alfalfa, almonds, celery, spinach,

mushrooms, pistachios, peaches and walnuts.



Phorate: (Low)

1. Use/source: Organophosphorous Insecticide

2. Soil: With a Koc of 3200, phorate is expected to have low mobility in soil,

although it has potential to leach through soil and contaminate groundwater in

sandy soils with shallow aquifers. Phorate may also be removed from the soil by

volatilization, photolysis, oxidation and hydrolysis. Volatilization of phorate may

occur from moist soil surfaces, but is not likely on dry soil surfaces. A photolysis

half-life of 1.8 days in soil at 25oC was measured for phorate. Phorate is rapidly

oxidized to sulfoxide and sulfone, which are more persistent than phorate.

Appendix D, Delta Dredge Strategy D-27





3. Water: Phorate is expected to absorb to suspended solids and sediment in water.

It may volatilize from water surfaces, but the presence of sediment in the water

column has been shown to inhibit volatilization. Estimated phorate half-life is 14

days in a model river and 100 days in a model lake. A hydrolysis half-life of 4

days at 25 oC was calculated at neutral pH. With a calculated BCF of 560,

bioconcentration in aquatic organisms is estimated to be high.

4. Atmosphere: Phorate is expected to exist solely as a vapor in the atmosphere.

Vapor-phase phorate is degraded in the atmosphere by reactions with hydroxyl

radicals with a half-life of 1.5 hours.

5. Toxicity: Like other organophosphorus insecticides, Phorate acts on the

acetylcholinesterase function at nerve junctions. Acute exposures can result in

CNS disorders including confusion, tremors, and cardiac arrythmia, The

accumulation of acetylcholine in CNS is believed to be responsible for mental

disorders and epilepsy, endocrine, cardiovascular, respiratory and gastrointestinal

disorders.



Phosmet (Low):

1. Uses/Sources: organophosphorous insecticide (cholinesterase inhibitor)

2. Soil: Phosmet has a Koc of 820 and is not expected to leach, although it has been

found in leachates near a pesticide manufacturing plant. The main route of

degradation in moist soil is by hydrolysis, with a hydrolysis half-life listed as 19

days. Other laboratory experiments have reported soil half-life of 51 to 60 days.

Volatilization is not expected to be important.

3. Water: Hydrolysis is also the major degradation pathway in for phosmet in water.

Reported half-lives range from 4 hours to 7 days between pH 6 and 8. Due to the

Koc, sorption to sediment may be an important fate. Volatilization and

bioconcentration are not significant for phosmet.

4. Air: Phosmet can exist in both the vapor phase and particulate phase in the

atmosphere. Vapor phase degradation occurs rapidly by reacting with hydroxyl

radicals with and estimated half-life of 2.6 hours. Particulate phase phosmet may

be removed by wet or dry deposition.

5. Toxicity: Dermal exposure may result in skin and eye irritation. Symptoms after

oral, dermal or inhalation exposure include: nausea, vomiting, excessive

salivation, headache, chest pain, loss of muscle coordination, random jerky

movements, confusion, coma and death due to respiratory failure. Oral LD 50 in

rats: 113 mg/kg. LC50 Chinook salmon: 180 ppb.



Piperonyl Butoxide (Low)

1. Uses/Sources: Used as a synergist for pyrethrins, rotenone and related

insecticides

2. Soil: With a theoretical Koc of 70, piperonyl butoxide is expected to be highly

mobile in soil, and therefore is expected to leach. Although compounds similar to

piperonly butoxide are biodegradable, no information is available on its

biodegradation or half-life in soil.

3. Water: Piperonly butoxide is not expected to adsorb to sediments or volatilize

from the water column. It may possibly be removed to some extent by

Appendix D, Delta Dredge Strategy D-28





photodegradation, but the half-life in water is unknown. Other degradation

pathways are unknown. Piperonyl butoxide is estimated to be moderately

bioconcentrating in aquatic organisms.

4. Air: In the air, vapor phase piperonyl butoxide will rapidly degrade (estimated

half-life of 3.4 hours) by reacting with hydroxyl radicals.

5. Toxicity: No known effects from exposure to piperonyl butoxide, except that

large doses have caused vomiting and diarrhea. The probable oral lethal dose in

humans is 5-15 g/kg (between 1 pint and 1 quart). Oral LD50 in rats is 7500

mg/kg.



Polyethylene Glycol (AlkylArylPoly/Oxyethylene glycol) (???)

1. Uses/Sources:

2. Soil:

3. Water:

4. Air:

5. Toxicity: Polyethylene glycol is listed with the following characteristics: not

significantly irritating to skin, eyes or mucous membranes, low vapor pressure so

no hazard from inhalation, exceptionally low oral toxicity.



Potash (Low):

1. Uses/source: Fertilizer

2. Soil:

3. Water:

4. Atmosphere:

5. Toxicity:



Propanil (Low)

1. Uses/Sources: Post emergent herbicide (commonly used in rice)

2. Soil: Koc values from 149 to 220 indicate that propanil may potentially leach, but

field studies have shown it to be largely immobile. Propanil degrades mainly by

microbial degradation, although photolysis may also occur on soil surfaces.

Laboratory studies have shown the soil half-life to range from 1 to 3 days under

warm moist conditions.

3. Water: Propanil degrades in water by microbial degradation and photolysis. The

expected half-life in water is 17 to 154 hours for biodegradation and 4 hours for

photolysis. The major degradation product is 3,4-dichloroaniline. Based on

theoretical calculations, adsorption, volatilization and bioconcentration are not

considered important.

4. Air: Propanil can exist in both the vapor phase and particulate phase in the

atmosphere. Vapor phase degradation occurs rapidly by reacting with hydroxyl

radicals with and estimated half-life of 24 hours. Particulate phase propanil may

be removed by wet or dry deposition.

5. Toxicity: Dermal exposure may result in skin and eye irritation and chloracne.

Symptoms after oral exposure include: burning sensation, gagging, coughing,

nausea, vomiting, headache, dizziness, confusion, and CNS depression.

Appendix D, Delta Dredge Strategy D-29





Propetamphos (High):

1. Type: Organophosphate Insecticide

2. Soil: No information is available on the fate of Propetamphos in the soil.

3. Water: The estimated half-life is 47 days in water at neutral pH and 25oC.

However, the compound may be significantly more persistent in cooler

temperatures, with an estimated half-life of five years at 30oC.

4. Atmosphere:

5. Toxicity: Propetamphos is a cholinesterase inhibitor that acts on the central

nervous system. This compound has not been found to have carcinogenic,

teratogenic or reproductive effects in lab animals. This compound is moderately

toxic to wild birds and highly toxic to fish. The oral LD50 in rats is 79 to 115

mg/kg.

6. Uses: Propetamphos is a household and public health insecticide used to control

cockroaches, fleas, ants, ticks, moths, flies, and mosquitoes on contact. It is also

used to control skin parasites in livestock.



1,2 Propylene Oxide (Low)

1. Uses/Sources: fumigant used in food packaging and storage

2. Soil: Propylene oxide is expected to leach in soils, based on estimated Koc below

30. It may volatilize rapidly from dry soils, and moderately from moist soils.

Degradation by hydrolysis may also be an important fate.

3. Water: In fresh water, propylene oxide will degrade by hydrolysis with a half-life

of 6 to 11 days. Degradation rates are enhanced by the presence of the chloride

ion so that the half-life in seawater is only 1.5 to 5 days. Volatilization may also

be important with a reported half-life of 10 hours in one river. Theoretical BCF

and Koc values indicate that neither bioconcentration nor sorptions to sediments

are important fates.

4. Atmosphere: Proplylene oxide exists in the vapor phase in the atmosphere where

it degrades slowly by reacting with hydroxyl radicals. The estimated half-life in

the atmosphere is 30 days.

5. Toxicity: Dermal exposure can result in irritation and necrosis of skin. Exposure

to vapors can cause irritation to eyes, upper respiratory tract and lungs. Corneal

burns have been caused by prolonged exposure to propylene oxide vapor. Other

symptoms include depression of the CNS, nausea, vomiting, and incoordination.

Propylene oxide is listed as a possible human carcinogen. There is inadequate

data in humans, but propylene oxide has been shown to cause cancerous tumors in

animals.



Pyrethrin II (???):

1. Use/source: Natural Insecticide

2. Soil: Pyrethrin II may be susceptible to photolyse on the soil surface and

hydrolysis in basic soil. This chemical rapidly oxidizes in the air, which is

important for aerobic soils. This chemical was found to undergo biodegradation

in the soil. Pyrethrin II may absorb strongly to suspended solids and sediment in

water and soil. Since pyrethin II is strongly absorbed onto soil, leaching may not

be important.

Appendix D, Delta Dredge Strategy D-30





3. Water: Pyrethrin II is unstable in light and therefore photolyse in the surface

water and hydrolyse in water to nontoxic products. The bioconcentration factor

for this chemical is 320 but since it rapidly degrades in the water and is

metabolized in fish, it is not likely a problem. This chemical is nonvolatile in

water.

4. Atmosphere: PyrethrinII is rapidly oxidized in the air. The half-lives for the

vapor-phase reaction of pyrethrin II with ozone and photochemically produced

hydroxyl radicals have been estimated to be 0.5 hour and 1.3 hour.

5. Toxicity: Pyrethrin II is a contact poison that rapidly penetrates into the nervous

system. In animals, large oral, inhaled, or topical doses of this chemical have

produced CNS excitation, incoordination, tremors, seizures and death. This

chemical also affects the immune system, by suppressing it.



Simazine (Low)

1. Uses/Sources: triazine herbicide

2. Soil: The major fate of simazine in the soil is microbial degradation, with a half-

life ranging from 27 to 102 days, depending on temperature and moisture.

Hydrolysis may also occur, with a reported half-life of 37 days at 20 degrees C,

and considerably longer at lower temperatures. Volatilization is not expected to

occur. Estimated Koc values ranged from 78 to about 3,600, indicating that

leaching may be possible.

3. Water: Simazine may somewhat adsorb to sediments and suspended solids.

Simazine is not expected to volatilize. Hydrolysis, photolysis and biodegradation

may all contribute to the removal of simazine from the water column. The

estimated half-life depends on temperature, pH, presence of organic matter, and

turbidity. One river sample demonstrated a simazine half-life of 16 days.

4. Atmosphere: Simazine may exist in both the vapor phase and the particulate

phase. Vapor phase simazine degrades rapidly by reacting with hydroxyl radicals

with and estimated half-life of 22 hours. Particulate phase simazine is removed

by wet and dry deposition.

5. Toxicity: Dermal exposure has caused acute dermatitis. No known oral ingestion

by man to determine oral toxicity. There is some limited evidence that triazine

herbicides such as simazine may be related to increased incidence of ovarian

cancer.



Sodium tetrathiocarbonate (Low):

1. Uses/source: Soil Fumigant, Nematocide

2. Soil: When sodium tetrathiocarbonate is applied to the soil, it rapidly

decomposes. forming carbon disulfide, which is an effective soil fumigant. The

gas dissipates quickly and degrades by oxidation creating sulfates and carbonates

as products.

3. Water:

4. Atmosphere: The decomposition product, carbon disulfide, exists in the vapor

phase but is rapidly degraded by oxidation resulting in sulfates and carbonates.

5. Toxicity:

Appendix D, Delta Dredge Strategy D-31





Sulfometuron methyl (Low):

1. Uses/source: Herbicide used on non-cropland

2. Soil: The compound is more strongly absorbed to acidic soils and to soils with a

high organic content than to alkaline soils with low organic content. The half-life

is approximately 1 month in soil, but may persist longer in cool, low moisture or

alkaline soils. Sulfomturon methyl degrades quickly in sunlight with an estimated

half-life of 1 to 3 days. There is some evidence that sulfometuron may also

inhibit soil bacteria and fungi.

3. Water: This compound is practically insoluble in water, however some

granulated formations may remain suspended in the water column. The potential

for bioaccumulation in fish is low.

4. Atmosphere: This compound does not evaporate easily.

5. Toxicity: Sulfometuron methyl is readily absorbed through leaves and roots,

halting plant growth by inhibiting cell division in growing tips, roots, and shoots.

This compound is slightly toxic to fish (LC50 for trout is <12.5 ppm) and aquatic

invertebrates, mammals and birds. No carcinogenic, mutagenic or developmental

effects were observed.



Sulfur: (?)

1. Uses/sources: Fungicide

2. Soil: Solid sulfur is insoluble in soil and not likely to leach into the groundwater.

3. Water:

4. Air:

5. Toxicity: Inhalation & exposure to dust may irritate respiratory tract, eyes and

skin.



Thiobencarb (Low)

1. Uses/Sources: herbicide (rice)

2. Soil: With measured Koc values ranging from 300-5,000, thiobencarb is expected

to have low mobility in the soil. Microbial degradation is the major removal

mechanism, although photodegradation may occur on soil surfaces. The half-life

of thiobencarb in soil is reported as 2-3 weeks under aerobic conditions and 6 to 8

months under anaerobic conditions. Microbial degradation may occur more

rapidly in soils that have been acclimated to thiobencarb.

3. Water: Adsorption to sediments may be an important removal mechanism for

thiobencarb in the water column. Thiobencarb may degrade by microbial

degradation or photooxidation. Laboratory studies have measured the half-life of

thiobencarb in the water to be 6 to 42 days. Volatilization is insignificant.

4. Air: Thiobencarb exists mainly in the vapor phase in the atmosphere. The

primary route of degradation is reaction with hydroxyl radicals, with an expected

half-life of 17 hours.

5. Toxicity: Thiobencarb may cause eye and skin irritation. Oral LD50 in rats is

920-1903 mg/kg. The LC50 in Rainbow trout is 1.2 ppm/9 hours at 12oC.

Appendix D, Delta Dredge Strategy D-32





Thiophanate-methyl (High):

1. Type: General-Use Fungicide

2. Soil: Thiophanate-methyl degrades rapidly in soil and has little effect on soil

bacteria. Thiophanate-methyl and its main breakdown products bind to soil

particles and are not very mobile in the soil. Faster degradation takes place in

alkaline and silty loam soils and has a half-life of about 7 days. The main

breakdown product of thiophanate-methyl in the soil is the active fungicide

methyl-2-benzimidazole carbamate (MBC). This compound has a half-life of

6-12 months in the soil and 3 to 6 months on turf or other vegetation. It is

incompatible with other pesticides alkaline in reaction or copper compounds.

3. Water: Very low solubility in water as a pure compound. The potential for

leaching is low since thiophanate-methyl and MBC are absorbed to soil particles.

Thiophanate-methyl has a half-life of 5 days at a pH of 5-10 if exposed to

sunlight. The breakdown product, MBC, has a half-life of 19 days at neutral pH.

In some aquatic organisms (including trout, carp, and invertebrates) thiophanate-

methyl is slightly to moderately toxic, but it is highly toxic to catfish. It doesn’t

seem to bioaccumulate in fish but one study showed that the half-life in trout is

about two weeks. It may be a hazard to endangered species if it is applied to areas

where they live.

4. Atmosphere: Thiophanate-methyl does not volatilize easily.

5. Toxicity: Thiophanate-methyl is absorbed by the fungus cells and interferes with

the functioning of microtubules, which are a part of the DNA-synthesizing and

chromosome moving process taking place during cell division. Treated cells

cannot divide so growth is therefore inhibited. This compound, in laboratory

studies has been shown to cause liver tumors in mice, minor skeletal

abnormalities and fewer fetuses in rabbits, decreased spermatogenesis in rats, and

a higher mutagenic potential in mouse bone marrow cells. Thiophanate methyl is

not toxic to plants but has been seen to cause abnormalities in developing

embryonic shoots and pollen mother cells, in some studies. This compound is

toxic to earthworms. May be a hazard to endangered species if it is applied to

areas where they live.

6. Uses: Thiophanate-methyl is used to control fungal diseases in the field, on turf,

on ornamentals and nursery plants, and in greenhouses.



Triclopyr (Low):

1. Use/source: Herbicide

2. Soil: Triclopyr is degraded by soil microorganisms but has a moderate

persistence in the soil. The half-life in soil ranges from 30 to 90 days, depending

on soil type and conditions. Soil with cold or arid conditions may result in a

significantly longer half-life. Triclopyr is not strongly absorbed to soil particles

and has the potential to leach.

3. Water: Triclopyr mainly degrades by photolysis, with an estimated half-life of

2.8 to 14.1 hours, depending on season and depth of the water. Hydrolysis is not

an important degradation mechanism at pH found in natural waters.

4. Atmosphere:

Appendix D, Delta Dredge Strategy D-33





5. Toxicity: Triclopyr does not appear to cause reproductive, teratogenic, mutagenic

or carcinogenic effects. Organs affected by exposure to triclopyr include the

kidneys and liver. Triclopyr is rapidly eliminated via the urine as the unchanged

parent compound. The half-lives for elimination of triclopyr in mammals are 14

hours in dogs and 24 hours in monkeys. For humans a half-life of 5 hours was

determined. This compound is non-toxic to birds and fish. The potential for

bioconcentration is low. The oral LD50 in rats is 630 mg/kg.



Triflumizole (Low):

1. Uses/source: Fungicide

2. Soil: Triflumizole has low potential for leaching. In the soil, this compound is

degraded rapidly by microbes, with an estimated half-life of 18 days in sandy

loam. One of the intermediates of degradation, 4-chloro-2-trifluoromethylaniline,

can be volatilized.

3. Water: Triflumizole is stable at near neutral pH, but may degrade slowly by

hydrolysis in mild acidic or basic conditions. The hydrolysis half-life at pH 7 is

64 days, but reduces to 3.9 days at pH 9.

4. Atmosphere:

5. Toxicity: The liver is the main target of triflumizole, followed by the ovary and

kidney. No carcinogenic or mutagenic effects were seen. This compound is non-

toxic to honeybees and birds but moderately to highly toxic to fish. The oral

LD50 in rats in 2.05 g/kg.



Trifluralin (Low)

1. Uses/Sources: pre-emergence herbicide

2. Soil: Trifluralin will not leach when released to soil, but is expected to volatilize

from both moist and dry soils. Trifluralin may also biodegrade under both aerobic

and anaerobic conditions, forming 3,4,5-benzotriamine. Degradation is faster in

anaerobic soils. The persistence of trifluralin in the soil is estimated at 6 months

or less.

3. Water: The sorption coefficient of 30,550 indicates that trifluralin will sorb

strongly to sediments. Rapid volatilization is also expected. If there is any left in

the water, it may under go biodegradation. Bioconcentration in fish is possible

and has been detected (BCF 1,700-5,400).

4. Atmosphere: Trifluralin degrades rapidly when exposed to sunlight, with an

estimated half-life of 25 to 60 minutes.

5. Toxicity: Inadequate evidence to classify carcinogenicity. No fatalities from 16

acute poisoning episodes. Oral LD50 in rats: 500 mg/kg.



Triforine: (Low)

1. Uses/source: Fungicide

2. Soil: The half-life for triforine in soil is estimated at 3 weeks.

3. Water: No information is currently available.

4. Atmosphere:

5. Toxicity: Triforine has low oral and dermal toxicity and moderate inhalation

toxicity. The acute oral LD50 for triforine in rats is greater than 16,000-mg/kg-

Appendix D, Delta Dredge Strategy D-34





body weight. Triforine is considered non-toxic to birds and low hazard to

honeybees, fish and aquatic invertebrates. Triforine is not considered a mutagen,

teratogen or a carcinogen.



Ziram (Medium)

1. Type: Fungicide

2. Soil: Ziram adsorbs moderately to the soil or sediment. No data could be found

on its persistence. Ziram is toxic to bacteria, biodegradation may be rather slow

or occurs only at very low concentrations.

3. Water: Ziram may adsorb to sediments. No data could be found on degradation

pathways or persistence in the soil. It is not expected to bioaccumulation

significantly.

4. Air: In the environment, ziram would exist primarily as an aerosol or dust that is

subject to gravitational settling. Although it is reported to degrade by UV light,

no photolysis rates could be found.

5. Toxicity: Dermal or inhalation exposure to dust can cause eye, skin and upper

respiratory irritation and difficulty breathing. The thyroid is the target organ for

this compound. Acute oral exposures include symptoms of abdominal pain,

neural and visual disturbances, brain edema and hemorrhage, liver and kidney

damage, and death. Chronic sublethal exposures in animals have caused

decreased body weight, immunological changes, sterility, and soft tissue

sarcomas. Oral LD50 in mice: 17 mg/kg, LC50 in Tilapia metanopleura: 5-10

mg/l.

6. Uses: Ziram in applied to fruit and nut trees to protect against fungal diseases.

Over 75% of the Ziram applied in California was applied to almond trees. Other

crops include peaches, nectarines and pears.







i

EPA Superfund Record of Decision (ROD) Abstracts

http://www.epa.gov/superfund/sites/rodsites/carcnty.htm

ii

Stockton Naval Communication Station Draft Final Surface Water and Sediment Site Investigation

Sampling and Analysis Plan Addendum