PUBLIC HEALTH ASSESSMENT

WELDON SPRING ORDNANCE WORKS
WELDON SPRING, ST. CHARLES COUNTY, MISSOURI

TABLES

Table 1 - WSTA Contaminant Pathway Evaluation

Table 2 - Surface Water Contaminants

Table 3 - Groundwater Well Usage at Twin Island Lake Resort

Table 4 - Past Test Results from Twin Island Lake Resort Wells

Range of Concentrations (ppb) from Six Sample Runs

Table 1.

WSTA Contaminant Pathway Evaluation

Pathway	Contamination Location	Exposure	Receptor Population\Population Size	Current Path
Groundwater	WSTA, conservation areas (springs) and offsite wells	drinking water, dermal contact	conservation area visitors\unknown	yes*
			past private wells (Twin Island Lakes Resort)\none	no
Soil	WSTA and conservation areas	access restricted	site workers and infrequent trespassers\unknown	possible **
Biota	possibly on and offsite	consumption of game and fish	onsite trespassers, hunters and anglers offsite\unknown	possible ***

*    Incidental ingestion is not sufficient to result in adverse health effect
**    Contact with contaminated soil is restricted by institutional controls.
***    Adverse health effects unlikely due to low levels of contaminants in fish and infrequent consumption

Table 2.

Surface Water Contaminants

Water Body	Contaminant(s)	Concentrations
Lake 10	1,3,5 TNB	0.08 ppb
	o-nitrotoluene	0.06 ppb
Lake 23	1,3,5 TNB	0.11 ppb
	m-nitrotoluene	0.07 ppb
	p-nitrotoluene	0.06 ppb
Lake 32	o-nitrotoluene	0.06 ppb
Lake 35	p-nitrotoluene	0.07 ppb
	1,3,5 TNB	0.1 ppb
Lake 36	1,3,5 TNB	0.08 ppb
Hampton Lake	m-nitrotoluene	0.27 ppb
	o-nitrotoluene	0.12 ppb

From:(1) Contaminant detections do not exceed CVs.
TNB CV = 0.5 ppb
No CV for m-, n-, o-, p-nitrotoluene, for comparison 2,4-DNT CV = 20.0 ppb, 2,4,6-TNT CV = 1.0 ppb

NOTE: Nitroaromatic contaminants not detected in former lagoons.

Table 3.

Former Groundwater Well Usage at Twin Island Lake Resort From:(4)

ID Number	Depth	Description and Use
#1	111 Ft.	Potable water to campsites. Connected to #61.
#2	220 ft	Potable water to sites. Not used "very often" water is rusty. Connected to #4.
#3	90 ft.	Potable water to sites and resort office.
#4	235 ft.	Potable water to sites. Connected to #2.
#61	?	Potable water to owner's house and sites. Connected to #1.
Swim Lake Well	630 ft.	Water for swimming lake only.
Goldfish PondWell	12 ft.	Water to goldfish pond used only for children's catch and releasefishing.

Table 4: Past Test Results from Twin Island Lake Resort Wells Range of Concentrations (ppb) from Six Sample Runs (1989) From: (4)

Table 4.

Past Test Results from Twin Island Lake Resort Wells Range of Concentrations (ppb) from Six Sample Runs (1989) From: (4)

Well ID#	#1	#3	#4	#61* *Owner's private well	Goldfish Pond
Chemicals
2,4,6-TNT	0.2 - 0.32	0.03 - 0.6	<0.03 - <0.25	0.04 - <0.25	0.03 - 0.04
*CV - 1.0/CREG C
2,4-DNT	0.03 - 0.05	<0.02 - 0.07	<0.02	<0.02	<0.02
CV - 20.0/EMEG child
2,6-DNT	0.03 - 0.17	0.08 - 0.19	<0.01	<0.01	0.05 - 0.07
CV - 400.0/CLHA
1,3,5-TNB	0.14 - 1.16	0.1 - 1.8	<0.03	<0.03 - 1.0	<0.03
CV - 0.5/RMEG child
1,3-DNB	<0.09	<0.09 - 0.2	<0.09	<0.09	<0.09
CV -1.0/LTHA and CREG D

* CV - ATSDR Comparison Value

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