PUBLIC HEALTH ASSESSMENT
U.S. NAVAL SUBMARINE BASE, NEW LONDON
GROTON, NEW LONDON COUNTY, CONNECTICUT
|Combined Census Tracts|
|% Male||88.4||51.4 |
|% Age 65|
|Median rent paid,|
Source: 1990 Census of Population and Housing, Summary TapeFile 1 (Connecticut). Prepared by Bureau of the Census,Washington, D.C., 1991.
|Cancer Incidence Rates per 1000|
(Direct Age Adjusted)
|Cancer Types||1979 - 1981||1984 - 1986|
Comments on New London Submarine Base Public Health Assessment
The comments listed here were received by ATSDR in response to thepublic comment period for the New London Submarine Base PublicHealth Assessment. The list of comments does not include editorialcomments concerning word spelling, sentence syntax, etc. It alsodoes not include comments on accuracy of stated facts. If theaccuracy of a statement was questioned, the statement was verifiedor corrected. Comments which requested that additional informationbe added to the document are not addressed here. The portions ofthe comments below that are in parenthesis were paraphrased by ATSDRfor brevity or clarity.
Lead, boron, cadmium, VOCs and sodium were found at varying levelsin the residential well supplies. Some of these (cadmium and VOCs)were only detected in one well, others were found in some or all ofthe wells (lead, boron, sodium). The report indicates that severalrounds of testing were done. However, not all wells were tested forthe same parameters, and it does not appear that confirmatorytesting was done to verify all of the results from the first round(not all wells were resampled). This may be an important omission.One round of sampling is not conclusive, especially when importantdecisions about health and risk are to be based on the results. Abetter approach might be to sample the wells regularly, perhapsquarterly for a year, to obtain data on possible fluctuations in thewater quality. This would offer a more accurate picture of the waterquality and a better basis for making decisions.
Over the entire course of sampling, a total of 23 different off-baseresidential wells were sampled. During the first sampling round, 14wells were sampled. A second round of sampling included those wellsthat showed detectable contamination during the first round plus theaddition of eight unsampled wells.
Further sampling was performed by the Navy and ConnecticutDepartment of Environmental Protection. Although no two samplingrounds contained analysis from all 23 wells, confirmation samplinghas been performed on all but one of the 23 wells (OSW 11). Inaddition, the Navy is designing plans for a detailed hydrogeologicinvestigation of this well, its groundwater and surface waterinteraction.
Because confirmatory sampling indicates that sodium is the onlygroundwater contaminant, and because no groundwater plume ofcontamination has been identified, routine monitoring is notrecommended at this time. When further information becomesavailable in the Phase II Remedial Investigation, ATSDR willevaluate that information and make further recommendations toprotect the health and safety of the citizens.
The report does not include any hydrogeologic data from this area.The wells may look from the surface to be "geographically isolated",but may in fact be hydrologically connected. Additional work shouldbe done in this area to determine the hydrology and locate anypotential contamination sources.
This public health assessment does not go into the detailed studiesperformed by the Navy on the hydrology of the base. Thatinformation is in the Navy documents located in the three localrepositories: Bill Library, Ledyard, CT, Groton Public Library,Groton, CT, and New London Submarine Base Library, Groton, CT.
The Navy has planned a detailed hydrogeological investigation of theadjacent off-base areas in the Phase II Remedial Investigation.
It is concluded that the lead problem might be due to plumbing inthe residences, rather than coming from the groundwater. This ispossible, so why not sample the water immediately after the watertank, before the household plumbing, to determine if this is indeedso. If the problem is in the house, it still should be monitoredand/or addressed.
In January 1993, the Navy resampled the two wells that had elevatedlead levels. Four samples of each well were taken. Water was takenat the well head and at the tap prior to flushing, then again aftera five minute flushing at both locations. Well OSW 10 showed leadlevels to be below the detection limit of 3 ppb in all foursamplings. Further analysis by another lab showed the actual leadconcentration to be 1.7 ppb. Well OSW 23 showed lead levels rangingfrom < 3 ppb to 37 ppb. This residential well showed lead levels tobe lowest (< 3 ppb) after flushing the line for five minutes andhighest prior to flushing.
As discussed in the Recommendations section of this document, ATSDRrecommends to the resident using well OSW 23 allow their water torun for a few minutes prior to using it.
There is a statement that shellfish harvesting is prohibited in theThames River because of high fecal coliform. However, there areseveral leased shellfish beds on the east side of the Thames Riverin Ledyard just north of the Subase. Harvested shellfish aredepurated prior to sale. I would like to see shellfish from bedsnear the Subase included in the biota sampling program.
The State of Connecticut Department of Environmental Protection inconjunction with the Connecticut Department of Health Servicesmaintains active monitoring of shellfish from the Thames River. Analysis of several species of mollusks include inorganic chemical,PCBs, pesticides, VOCs as well as bacteriologicals such as fecalcoliform testing. Quarterly monitoring results show only bacterialcounts to be above health based standards.