Frequently Asked Questions
What happens if the treatment plant fails or needs maintenance for a day or so?All municipal wastewater treatment facilities must meet certain statemandated design criteria to account for these situations. Emergency power generators are required to maintain operations during power outages. DEP requires that all processes have redundant equipment, so that full treatment can be provided with any one treatment “train” out of service. (Most treatment facilities are designed with two or more parallel treatment processes, called trains, for this reason. Larger facilities might have 3, 4, or more separate, identical trains.
What about the remaining 5 other areas including the trailer parks? Does this mean several other treatment plants and leaching fields?The current approach is to look at several dispersal sites for discharge of the treated effluent, since the likelihood of any one site handling all the flow is small. The consultants, in conjunction with state and local regulators, will evaluate what the most environmentally sound, costeffective approach is to treat the wastewater and disperse the effluent. This could result in one or more treatment facilities distributing the effluent to several different sites
I was assured the treatment facilities would remove ALL the nitrogen, toxins and viruses but we would need more evidence than CDM's word. Using the school is playing with fire.Current wastewater treatment technology is designed to reduce concentrations of conventional pollutants (BOD5, Suspended Solids, Nitrogen) to levels consistent with state permitting standards. This generally results in BOD5 and Suspended Solids concentrations in the effluent of about 10 parts per million (influent is about 300 ppm), and total nitrogen of about 5 ppm (influent is about 60 ppm). Additional treatment is then available in the soils which will reduce these pollutants further.
Pathogenic bacteria and viruses are killed or inactivated by exposure to intense doses of ultraviolet light (Chlorine, once the standard disinfection method, is used less often now due to its residual effects.)
Other toxins (Pharmaceuticals and Personal Health Care products, or PPHC) as well as other toxic compounds, are dealt with using a combination of treatment, source reduction and regulation. However, the best treatment is educating the users not to discharge toxic substances down the drain in the first place.
Large treatment systems, whether using a surface water discharge or subsurface dispersal, are regulated by CT DEP, who will issue an operating permit (also called a discharge permit) for the facility which includes limits for concentrations of pollutants in the effluent. These treatment facilities are required to constantly monitor their operational parameters (much of which is now done electronically), submit operating data to DEP on a monthly basis, and are subject to inspection by DEP field inspectors.
How could the engineering studies by 2 different companies vary for Elliott from 12,000 to 200,00 gallons per day?It’s not clear where the two numbers you are referring to originate. At the present time, the data from Elliott school is still being evaluated, and no estimates for site capacity have been arrived at by the current consultant.
One way a site could have two such disparate values is the following: The lower number could be the theoretical capacity of a site with a conventional septic tank and leaching field, where the soils are being used to provide a significant part of the treatment. The higher number could be the site’s hydraulic capacity; that is, the capacity of the site to merely accept a discharge of water with no consideration or expectation of soil-based treatment. The latter would assume that all treatment was accomplished in a conventional treatment facility before discharge to the ground for dispersal.
At the Saybrook hearing, the cost of a AT (individual onsite Alternative Technology) system would be about $ 28,000 plus annual maintenance fees of anywhere between $ 1,000 and 5,000. That's a heavy load for many home owners.The estimated capital costs you identify are correct for Old Saybrook; the operational costs are estimated at between $600 and $800 annually per home. The economy of scale obtained by community systems, as being evaluated for the town of Clinton, helps to reduce the cost per user, both for capital costs and operational costs. It is not unreasonable to expect, however, that the individual costs for the cluster and community systems will be in the $15,000 - $20,000 range per home. This cost may be defrayed by grants from the DEP Clean Water Fund (a 25% grant, and a loan for the balance at 2% for 20 years), resulting in a monthly cost for the typical home of between $57 and $76. Assistance from other funding sources could reduce this further. Operational costs are likely to be in the range of $30 - $50 per month.
Again, a cost-effective analysis will be part of the alternative evaluation and selection process, to help minimize the economic impacts to the users.
Why can’t we just follow the Sewer Avoidance policy that the town adopted years ago?Sewer Avoidance refers to a strategy to avoid the need for sewers by assuring the proper design, construction, operation and maintenance of onsite system. (Today the term is Onsite Management). It is a preventative measure, not a remedial measure, and for that reason is not an appropriate strategy for developed areas where problems resulting from site constraints already exist. In other words, Sewer Avoidance won’t make the lots bigger, the groundwater deeper, or the soils better suited for wastewater treatment, and is therefore not a viable strategy in developed areas where those limiting factors already exist.
Why can’t we use water bodies other than the Hammonassett River to discharge treated effluent into? If the wastewater can be treated to nearly drinking water quality, why is it a problem?Surface water bodies which are not already receiving a discharge of treated effluent, or are otherwise impacted by pollution sources, are not allowed to begin receiving such discharges, regardless of the quality for the effluent, under the Federal Clean Water Act and the Connecticut Water Quality Standards. Since the Hammonassett both receives discharges and has historical pollution sources (old landfills, for example) alongside it, it was labeled Water Quality Class B, which allows for additional discharges as long as water quality standards are maintained in the receiving waters, and no degradation will occur due to the operation of the discharge. Other local water bodies (the Indian River, Menunketesuck River, and Long Island Sound in the vicinity of Clinton) are listed as Water Quality Class A, or SA in the case of Long Island Sound (the “S” prefix indicates a salt-water receiving water).
Feel free to send more questions if you want our take on the answers...
Dennis J. Greci, P.E.
Supervising Sanitary Engineer
Municipal Facilities Section
Bureau of Water Protection & Land Re-Use
Phone: (860) 424-3751