HEALTH CONSULTATION
Review of Groundwater Data
SIGMON'S SEPTIC TANK SERVICE FACILITY
(a/k/a SIGMON'S SEPTIC TANK SERVICE)
STATESVILLE, IREDELL COUNTY, NORTH CAROLINA
| CHEMICAL SUBSTANCE | CHEMICAL CONCENTRATIONS (ppb) | WATER COMPARISON VALUES (ppb) | FURTHER PUBLIC HEALTH EVALUATION REQUIRED | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Acute EMEGs | Intermediate EMEGs (14 < ___ < 365 days) | Chronic ( > 365 days) | EPA MCL | ||||||||||||
| Detected Concentrations | |||||||||||||||
| Non-carcinogenic | Carcinogenic | ||||||||||||||
| Range | Mean | Median | Adult | Child | Adult | Child | Adult | Child | |||||||
| INORGANIC MOITIES | |||||||||||||||
| Nitrates | 100 -- 23,350 | 8,164 | 8,600 | 60,000 | RMEG | 20,000 | RMEG | 10,000 | YES | ||||||
| Sulfates1 | 6,000 | 6,000 | 6,000 | 250,000 | NO | ||||||||||
| METALS | |||||||||||||||
| Aluminum | 200 -- 1,700 | 950 | 950 | 70,000 | 20,000 | 37,000 | RBC | 16,000 | RBC | NO | |||||
| Barium | 16 -- 400 | 164 | 90 | 2,000 | RMEG | 700 | RMEG | 2,000 | NO | ||||||
| Calcium | 21,000 -- 95,000 | 58,000 | 58,000 | NA | |||||||||||
| Cobalt | 1.2 -- 2.6 | 2.1 | 2.4 | 730 | RBC | 310 | RBC | NO | |||||||
| Copper2 | 14 -- 60 | 37.6 | 38 | 1,500 | RBC | 630 | RBC | 1,300 | NO | ||||||
| Iron1 | 14 -- 5,500 | 1,736 | 195 | 22,000 | RBC | 9,400 | RBC | 300 | YES | ||||||
| Lead2 | 2 -- 28 | 8.9 | 4.5 | 15 | YES | ||||||||||
| Magnesium | 1,600 -- 12,000 | 6,983 | 7,250 | NA | |||||||||||
| Manganese1 | 4.2 -- 830 | 153.1 | 78 | 2,000 | RMEG | 500 | RMEG | 50 | YES | ||||||
| Mercury5 | 1 -- 7 | 2.8 | 1.6 | 70 | 20 | 10 | RMEG | 3 | RMEG | 2 | YES | ||||
| Nickel | 2.3 -- 4.2 | 3.25 | 3.25 | 700 | RMEG | 200 | RMEG | NO | |||||||
| Potassium | 1,300 -- 7,000 | 2,990 | 2,150 | 2000 | 500 | NA | |||||||||
| Sodium3 | 5,300 -- 15,000 | 10,150 | 10,150 | 20,000 | NO | ||||||||||
| Zinc1 | 28 -- 2,500 | 541 | 155 | 10,000 | 3,000 | 10,000 | EMEG | 3,000 | EMEG | 5,000 | NO | ||||
| ORGANIC COMPOUNDS | |||||||||||||||
| Acetone | 5 -- 233 | 71.9 | 47.5 | 70,000 | 20,000 | 10,000 | RMEG | 3,000 | RMEG | NO | |||||
| Benzene | 0.4 | 0.4 | 0.4 | 11 | RBC | 4 | RBC | 0.6 | CREG | 5 | NO | ||||
| Bromodichloromethane4 | 3 | 3.0 | 3.0 | 1,000 | 400 | 700 | EMEG | 200 | EMEG | 0.6 | CREG | 80 | YES | ||
| Chlorobenzene | 0.4 | 0.4 | 0.4 | 10,000 | 4,000 | 700 | RMEG | 200 | RMEG | 100 | NO | ||||
| Chloroform4 | 0.6 -- 39 | 13.46* | 0.78* | 10,000 | 3,000 | 4,000 | 1,000 | 400 | EMEG | 100 | EMEG | 6 | CREG | 80 | YES |
| Dibromochloromethane4 | 1 | 1 | 1 | 1,000 | 400 | 1,000 | EMEG | 300 | EMEG | 0.4 | CREG | 80 | YES | ||
| 1,2-Dichlorobenzene | 0.3 -- 48 | 24* | 24* | 3,000 | RMEG | 900 | RMEG | 600 | NO | ||||||
| 1,4-Dichlorobenzene | 0.27 -- 44 | 3.91* | 0.77* | 10,000 | 4,000 | 75 | LTHA | 0.47 | RBC | 75 | YES | ||||
| 1,1-Dichloroethane | 0.4 -- 1.5 | 0.7* | 0.6* | 800 | RBC | 300 | RBC | NO | |||||||
| 1,2-Dichloroethane | 0.53 | 0.53 | 0.53 | 7,000 | 2,000 | 10 | RBC | 3.6 | RBC | 0.4 | CREG | 5 | YES | ||
| cis-1,2-Dichloroethene | 0.43 -- 3.5 | 1.3* | 0.8* | 40,000 | 10,000 | 10,000 | 3,000 | 61 | RBC | 22 | RBC | 70 | NO | ||
| Methylene Chloride | 2 | 2 | 2 | 7,000 | 2,000 | 2,000 | EMEG | 600 | EMEG | 5 | CREG | 5 | NO | ||
| Tetrachloroethene (PCE) | 0.29 -- 0.53 | 0.41* | 0.41* | 2,000 | 500 | 400 | RMEG | 100 | RMEG | 1.1 | RBC | 5 | NO | ||
| Trichloroethene (TCE) | 0.27 -- 0.89 | 0.5* | 0.35* | 7,000 | 2,000 | 37 | RBC | 13 | RBC | 1.6 | RBC | 5 | NO | ||
| Xylenes | 0.5 -- 5.1 | 2.2* | 1.6* | 7,000 | 2,000 | 10,000 | LTHA | 4,500 | RBC | 10,000 | NO | ||||
| Notes: | A chemical is selected for further public health evaluation if the maximum detected chemical level exceeds at least one of its comparison values. Shading indicates the comparison values that are exceeded. | ||||||||||||||
| CREG | = | Cancer Risk Evaluation Guide | |||||||||||||
| EMEG | = | Environmental Media Evaluation Guide | |||||||||||||
| LTHA | = | Drinking Water Lifetime Health Advisory | |||||||||||||
| MCL | = | Maximum Contaminant Level | |||||||||||||
| RBC | = | Risk Based Concentration (Note, RBC values derived from equations documented in following reference: EPA Region III Risk-Based Concentration Table. United States Environmental Protection Agency, Region III, 841 Chestnut Street, Philadelphia, PA, 19107. Available on EPA Region III’s Internet website, http://www.epa.gov/reg3hwmd/risk/ , Background Information - [PDF]) | |||||||||||||
| RMEG | = | Reference Dose Media Evaluation Guide | |||||||||||||
| NA | = | None Available | |||||||||||||
| ppb | = | parts per billion | |||||||||||||
| *Average and Median concentrations may be different than displayed in table since some detections were below the quantitation limit for the analyzed chemical (i.e., no value given in inspection/sampling report). | |||||||||||||||
| 1Listed value in "EPA MCL" column is a Secondary Maximum Contaminant Level (SMCL) for drinking water as set by EPA. SMCLs are unenforceable federal guidelines regarding taste, odor, color, and other non-aesthetic effects of drinking water. EPA recommends them to States as reasonable goals, but federal law does not require water supply systems to comply with them. States may, however, adopt their own enforceable regulations governing these concerns. | |||||||||||||||
| 2Listed value in "EPA MCL" column is a Maximum Contaminant Level Action (MCLA) for drinking water as set by EPA under Superfund. If the relevant action level is exceeded, a regulatory response is triggered. | |||||||||||||||
| 3Listed value in "EPA MCL" column is a Drinking Water Equivalent Level (DWEL). The drinking water standard is based on EPA's oral RfD and represent corresponding concentrations of a substance in drinking water that are estimated to have negligible deleterious effects in humans at an intake rate of 2 L/day, assuming that drinking water is the sole source of exposure; however, the listed standard for Sodium is only to be used as a guideline, similar to the Secondary Maximum Contaminant Levels. | |||||||||||||||
| 4Listed value in "EPA MCL" column is a proposed MCL under the 1994 proposed rule for disinfection by products rule; the current MCL for most trihalomethanes is 100 ppb under the 1996 Drinking Water Advisory Report. | |||||||||||||||
| 5Listed comparison values for inorganic mercury, except for EPA's MCL, are based on studies of animals administered high doses of mercuric chloride [ATSDR 1999a, NTP 1993, Druet et al. 1978, Bernaudin et al. 1981, Andres 1984]. | |||||||||||||||
Figure 1. Groundwater Sampling Locations for 1997 Preliminary Assessment / Site Inspection
Figure 2. Groundwater Sampling Locations for 1999 Expanded Site Inspection
Figure 3. On-site Monitoring Well Locations in Retrospect to the Former Lagoons
