4-1. WASTEWATER TREATMENT THRU SEWERS
The development of sewer service infrastructure has been crucial for the growth of the Housatonic Valley Region. From the land use planning point of view, sewers allow development densities to significantly exceed the otherwise natural site limitations of soil and slope.

Wastewater goes down the drain, and then to....

When municipal sewer service is available, the large land area normally required for on site wastewater disposal thru leaching fields is cancelled. This allows site development to be more dense, an appropriate change to land economics if in the proper location.

"Proper location" is a much debated question in the planning for this powerful public utility. Questions of community character are involved. Counter balancing issues include the potential negative effect of increasing stormwater runoff and vehicular traffic. HVCEO's Sewers and Growth Map directly addresses this question.

Photo courtesy of Rick Gottschalk

Planning for sewers must be carefully coordinated with the municipal plan of conservation and development. In 2008 CT DEP offered a guidance document on how to coordinate these two planning efforts. See this link to the CT DEP guidance or contact HVCEO for a hard copy.

Detailed histories on hvceo.org of sewer service development by municipality can be accessed below. These reviews assist each community in understanding its past sewer planning and its relationship to neighboring communities in sewer service matters:

1. LINK TO SEWER SERVICE ISSUES IN BETHEL
2. LINK TO SEWER SERVICE AVOIDANCE BRIDGEWATER
3. LINK TO SEWER SERVICE ISSUES IN BROOKFIELD

4. LINK TO SEWER SERVICE ISSUES IN DANBURY
5. LINK TO SEWER SERVICE ISSUES IN NEW FAIRFIELD
6. LINK TO SEWER SERVICE ISSUES IN NEW MILFORD
7. LINK TO SEWER SERVICE ISSUES IN NEWTOWN

8. LINK TO SEWER SERVICE ISSUES IN REDDING
9. LINK TO SEWER SERVICE ISSUES IN RIDGEFIELD
10. LINK TO SEWER SERVICE AVOIDANCE IN SHERMAN

Policy for the expansion of sewer service area is within the
municipal plan. The above excerpt from the 2001 Brookfield
Plan of Conservation and Development identifies existing
sewered areas in orange and future sewered areas in
yellow. Uncolored (white) areas are "not to be sewered."

With a lot of planning and inter-commission coordination, it is possible to counter unplanned affordable housing zoning overrides targeted at the vacant land in the municipal sewer service area. The Brookfield Plan of Conservation and Development of 2002 proposes a technique to achieve this goal.

According to the 2002 Brookfield Plan within the sewer service area, each parcel would be assigned a sewage allocation based on its current or anticipated water use based on: "a: the land use recommendations of this plan of conservation and development, and b: the capacity of the sewer infrastructure such as pipe sizes, flow rates, pump stations, and other considerations."

Since the statutorily authorized 8-30g zoning override is limited to zoning and the granting of sewer capacity cannot be forced by that law, a sewer capacity allocation plan tied to the plan of development preserves the integrity of planned densities. But, the technique takes a lot of work to set up.

The 2003 New Fairfield Plan of Conservation and Development makes a similar recommendation, that "each property in the service area receive a specific sewage discharge allocation that is related to the current use of property or the future development potential.."

The New Fairfield Plan also notes that "the Town of Simsbury, CT has used a limited capacity sewage disposal system (a sewer limit line with sewage allocations) for over thirty years. Simsury has found this type of system to be an important tool for supporting desired community development."

4-2. WASTEWATER TREATMENT THRU
ON SITE SUBSURFACE DISPOSAL SYSTEMS
Wastewater disposal in areas that are not served by public sewers use on site "subsurface disposal systems." They are also referred to as “septic systems."

Individual leaching fields rely upon the soil in the vicinity of the home or business to purify discharged wastewater. After migrating thru the ground, later in time the same water may then become water supply for a nearby property. Proper soil type is crucial to this much needed purification process.

There are many limitations upon this delicate process. These are caused largely by incompatible soil type. This important discussion is presented in Chapter 1, Section 1-2 entitled Fundamental Development Factors of Soil, Slope and Wetness.

Typical septic tank and leaching
field for a single family home

Approval of new subsurface disposal systems is a complex process involving design, site inspections, soil testing, and issuance of two separate permits. As a proper understanding of this process is vital for successful development and achieving the core values of this Regional Plan, a summary is provided below:

• Plans for new subsurface systems are typically prepared by engineers. They are then submitted to local health departments, that staff acting as agents of the State Commissioner of Health. Most, but not all, local health departments require that licensed professional engineers prepare these plans.

• Licensed sanitarians of local health departments evaluate the lot proposed for the septic system, which includes percolation tests, soil evaluation using deep test pits and make a determination of whether there are “areas of special concern.”

• The sanitarian also evaluates the plan to determine if it conforms to the technical standards of Section 19-13-B103b of the Connecticut Public Health Code. These standards dictate the minimum size and design standards for septic tanks and leachfields, availability of reserve areas, and other system engineering requirements.

• If the review of the engineer’s plan and the site inspection are deemed acceptable by the local health department sanitarian, a “permit to construct” is issued.

• Once the system is installed, the local sanitarian will return and inspect the site to verify the actual placement of the septic tank and leachfield on the lot and its conformance to an “as-built” plan prepared by the engineer. If the on-site installation is approved by the sanitarian, a permit to discharge is issued, allowing the system to operate.

• Local inland wetland agencies also have the authority to regulate construction of new septic systems in wetlands and regulated setback areas.

• For larger systems, including community septic systems and any discharge from a system greater than 5000 gallons per day, the Connecticut DEP must review and approve the design prior to the issuance of the local permit to discharge.

Installation of a subsurface leaching field

Unfortunately in all municipalities there are also significant issues with septic system failure and repair. The life of an septic system depends upon soil conditions and how well it is maintained. Properly designed and installed systems are expected to last 30 to 40 years. However, on site soil and hydraulic conditions will also determine the life of the system.

Homeowners are encouraged to inspect and pump out their septic tanks once every two years to maximize the life of their system.

Failure will cause sewage to back up into the dwelling or will result in the discharge of untreated sewage beyond the leachfield. When this occurs a repair is required, which needs prior approval by the local health department.

Correction of failing systems is usually self-enforcing, since most homeowners or businesses will not tolerate sewage back-ups or the appearance of raw sewage on or beyond their properties.

If a failing system is discovered by the local health department, health officials have both the authority and the obligation to issue an order to the property owner to correct the septic system.

Finally, it should be noted that local health departments (for all areas of the municipality) and water utilities (for public water supply watersheds only) have the authority to conduct “sanitary surveys” of neighborhoods to search for failing subsurface disposal systems.

For example the Danbury Water Department has one employee dedicated to routine inspections of all of the water supply watershed areas in Danbury. Once discovered by the Water Department, the Danbury Health Department will issue orders to the property owner to correct the failing septic system.

4-3. MINIMUM LOT SIZE AND SEPTIC DISPOSAL
Moving up to the broader planning view, in 1989 the Connecticut Department of Environmental Protection released a research report entitled “Report for the Blue Ribbon Commission on Housing on the Land Required to Support Residential Development in Connecticut."

The 1989 research and its minimum lot size recommendations are still supported by DEP and remain that Department's policy today.

The concern in the late eighties was that housing production was being held back by unnecessarily large lot zoning, and that wastewater treatment standards used to justify very large lot zoning were suspect. The 1989 DEP report was written specifically to clarify that situation.

Subdivision application showing proposed homes in black,
well locations in blue and individual leaching fields in dark orange.
After applying the health code's minimum setbacks between
well and wastewater disposal features, then setbacks
from property lines, the lot area has become large.

According to the still valid 1989 DEP report:

While critics have assailed current zoning densities in unsewered areas as overly restrictive, the Department disagrees. In the main we believe that the current restrictions in some of these areas are not as stringent as they should be.

The maximum density that we can support in unsewered areas is one dwelling unit for each 0.6 acres, under ideal conditions. However, the majority of base natural resource conditions mitigate towards a density of less than one dwelling per acre.

Many host conditions and potentials for new environmental damage require a density that is less than one house per two acres of “buildable”, non-wetlands soils.

The following densities or lot sizes are recommended for various natural resource conditions:

--- Minimum lot area, without public water, 1 unit/acre exclusive of wetlands; with public water, 1 unit/0.6 acre exclusive of wetlands.

--- In public water supply watershed, without public water, 1 unit/2 acres exclusive of wetlands; with public water, 1 unit/2 acres exclusive of wetlands.

--- In inland waterfront areas, without public water, 1 unit/1.5 acres exclusive of wetlands; with public water, 1 unit/1.5 acres exclusive of wetlands.”

Calculations of nitrogen loading factors under ideal, non-conservative conditions indicate that at least 0.6 acres is needed to dilute nitrogen. The figure of 0.6 acres applies only to lots that are provided with public water and provides little margin for error.

If a higher waste strength (70 mg/l) is utilized the lot size requirement jumps to 1.5 acres, just to dilute nitrogen. This still assumes that 1/3 of all rainfall infiltrates and the lot topography is regular, allowing dilution.

The topographic issue is another example where the assumptions in the DEP model are more clearly applicable to large systems, which must be spread out over extensive contour lines. The microtopography of subdivided land may be quite different from this, prompting caution in any infiltration analysis.

Whatever the quality of the system design,
it is imperative that the septic tank be cleaned
periodically in order to maintain its life expectancy.

As noted above DEP still supports the conclusions of the landmark 1989 research summarized above. The response to a February 2007 HVCEO inquiry to the DEP reaffirmed the validity of the 1989 study.

An interesting "second opinion" on this density and septic research issue has been prepared for adjacent Dutchess County, New York.

Concerning density in existing and potential water supply watersheds, a second and later DEP reference is also worth referencing. According to page 20 of the 1993 DEP report entitled Protecting Connecticut’s Water Supply Watersheds, “based on this review of the literature, it appears that a maximum density of 1 dwelling per 2 acres will provide adequate protection of water quality if pollution control measures, as presented in this Guide, are utilized.”

In response, existing and potential water supply watersheds in this Plan's Future Growth Map are recommended to remain unsewered and as low density areas, and exempt from further overrides for 8-30g affordable housing.

4-4. WASTEWATER TREATMENT
THRU COMMUNITY DISPOSAL SYSTEMS
The DEP report also indicated interest in creative subdivision development. But back in 1989 the practical details of such systems had not yet been worked out.

That situation has now changed. As documented below "community" disposal systems, with their open space, environmental and aesthetic benefits are now approvable by the Connecticut DEP.

Any such community system must be reviewed and approved by the CT DEP prior to issuance of a permit to construct and discharge. However, as noted in a 2007 White Paper on this subject prepared by the Nature Conservancy for towns in the Saugatuck Watershed, significant cautions still apply.

A technical report prepared for the 2004 Newtown Plan of Conservation and Development, entitled “Analysis of Open Space Conservation Subdivisions” provides an enlightened view of community disposal systems.

Community leaching field
serving multiple single family homes

According to the 2004 Newtown report:

When an open space conservation subdivision is proposed to use a community sewerage system, it is important for the developer to contact DEP early in the planning process to assess the technical feasibility of such a system and to understand how such a system will affect the design of the subdivision.

It may be possible to lay out an open space conservation subdivision that is served by one community leaching field or a solution may entail the development of two or more community leaching fields.

Although the concept may allow a subdivision to be developed with a substantial land area set aside for “open space,” it should be noted that leaching fields need to be maintained as grass cover, that is free of trees and shrubs, to allow for adequate evapotranspiration of moisture from the disposal system. This does not preclude the area to be created as a “conservation meadow habitat.”

The DEP will be interested in the hydraulics of the proposed system, the treatment of nitrogen and pathogens and the mixing of treated wastewater into the area’s ground water system.

In instances where soils and the ground water system are not supportive of a community sewerage system with a standard septic tank/leaching field operation, it may be possible to develop an approach that pre-treats effluents prior to discharging into a constructed leaching field.

Additionally, a subdivision may be developed with a "package treatment plant” involving a community wastewater disposal plant similar to those serving entire municipalities, but on a smaller scale. This also requires DEP approval and very strict management and maintenance requirements.

Package treatment plant

The Riverview condominium is a residential development in southern Newtown, constructed in the late 1990’s. The Riverview has forty-nine two bedroom housing units, with a combined sewage discharge of 14,700 gallons per day.

This project was reviewed and approved by DEP for a community sewerage system that includes a collection system, a community septic tank, distribution box and a community leaching field.

This green space at Newtown's Riverview
Condominium lies above its community leaching field

Prior to issuing a permit for a community sewerage system, the DEP required the Newtown Water Pollution Control Authority to signify that the Town is satisfied with the management structure, maintenance schedules and financial reserves established to manage, maintain and repair the system. Financial reserves are sized to enable the replacement of the system, if it were to fail.

Under state law, if a community sewerage system were to fail and the responsible homeowners association did not remediate the problems, the Town would become responsible for the cost of system repairs.

The Riverview homeowners association has an agreement with the Newtown Water Pollution Control Authority that governs the maintenance of the community sewerage system, as well as the reserve fund that was established to enable ongoing maintenance, repairs and system replacement, if required.

The presence of this community sewerage system in Newtown is an expression of confidence that DEP has in the long term performance of such systems.

The Riverview’s community sewerage system is located directly over the Pootatuck Aquifer and within the Town’s Aquifer Protection District, just upstream from the two United Water Connecticut wells that provide drinking water to 1,153 Newtown households.

As model residential subdivisions with community leaching systems, the 2004 Newtown report cites the new Great Oak Farm subdivision in nearby Monroe. The design of Great Oak Farm conserved 50% of the project area. The development is served by an on site community sewerage system that includes several leaching fields serving sub-drainage areas.

View of homes at nearby
Monroe, CT's Great Oak Farm Subdivision.

Another example cited by Newtown was Long Hill Farm subdivision in Guilford, containing 62 single family detached homes, that subdivision is served by a community septic system.

The design of the subdivision conserved significant amounts of open space, including woodlands and open fields, and also buffered the subdivision from view from the local town road.

4-5. WASTEWATER TREATMENT RECOMMENDATIONS
GOAL: Encourage coordination between local water pollution control authorities, which guide the geographic extent of local sewer development, and local planning commissions, as they prepare the municipal plan of conservation and development.

1. Cite as a good example of internal municipal coordination the New Milford Water Pollution Control Authority, which uses as its expansion guide the future sewer area map adopted by the New Milford Planning Commission in the municipal Plan of Conservation and Development.

2. As HVCEO and state plans recommend areas for sewer expansion and avoidance, consider this input when setting municipal sewer expansion policies in the municipal plan.

While the HVCEO Future Growth Map for sewered areas is advisory, the state plan map is a very strong influence on CT OPM and CT DEP as their approval is sought for sewer service area expansions. Coordinate local and HVCEO future sewered area policy and then seek to amend the state plan map to conform.

3. Following the Newtown example, selectively expand the use of community leaching fields to promote creative development and open space preservation.

4. Where planned density does not require sewers, subsurface septic systems are the remaining method for treating wastewater. Encourage conservative design of such septic systems and inclusion of sufficient reserve leaching area so that on site disposal functions in perpetuity, permanently avoiding the spread of sewers for remediation.

5. Encourage periodic septic tank cleaning. Regular septic tank maintenance is the single most important step to extend the life of the system.

6. Continue to support efficient and cost-effective regional treatment of septic tank residue (septage). A regional septage disposal system planned by HVCEO has been operating at the City of Danbury's Water Pollution Control Facility since 1988 and serves Bethel, Bridgewater, Brookfield, Danbury, New Fairfield, Newtown and Redding.

8. Encourage water conservation by businesses and households in order to reduce the amount of wastewater effluent to be treated. Promote the policy that water conservation extends the life of sewage treatment plants and septic systems and helps to protect water quality throughout the region.

The City of Danbury's sewer plant is the largest in the Region and
also serves six nearby towns. The title of this 1993 plant brochure
stresses the plant's regional role in environmental protection.

The contributions of consultant Jack Kozuchowski to
this section of the regional plan are gratefully acknowledged.

--- 1. INTRODUCTION --- 2. MAP OF GROWTH --- 3. WATER SUPPLIES ---
--- 4. WASTEWATER --- 5. TRANSPORTATION --- 6. GLOBAL WARMING --- 7. HOUSING ---
--- 8. ECONOMY --- 9. OPEN SPACE --- 10. MIX LAND USE --- 11. TOD --- 12. PEDESTRIAN ---