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HomeMy WebLinkAboutPreliminary Engineering Site Report – March 26, 2018 Prepared for: Prepared by: OLIVIA VENT JOHN M. ANDERSSON, P.E. ohv1@cornell.edu Consulting Environmental Engineer 1 Woodland Road Ithaca, NY 14850 Office 607-539-7096 Cell 607-229-6100 j.anderssonpe@yahoo.com March 26, 2018 PRELIMINARY SITE REVIEW Redevelopment of 1839-1849 DANBY ROAD Town of Danby Tax Parcels 502200-10.-1-42 and -49.2 DANBY TOWN HALL DANBY ROAD BALD HILL R O A D DANBY PARK ROAD DOTSTON PARK TRAIL DANBY COMMUNITY CHURC H -42 (2.1 A) -49.2 (2.4 A) NORTH 1 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association CONTENTS CONTENTS ...................................................................... 1 PROJECT DESCRIPTION and LOCATION .......................... 2 SENSITIVE ENVIRONMENTAL and HISTORIC FEATURES . 2 ZONING .......................................................................... 3 SOILS .............................................................................. 3 SEWAGE TREATMENT .................................................... 3 WATER SUPPLY ............................................................... 5 STORM WATER MANAGEMENT ..................................... 6 STATE ENVIRONMENTAL QUALITY REVIEW (SEQR) ....... 7 SUMMARY OF NEEDS FOR FURTHER INVESTIGATION ... 7 PROPERTY SKETCH ......................................................... 8 ATTACHMENTS ............................................................... 8 2 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association PROJECT DESCRIPTION and LOCATION 1839 and 1849 Danby Road; adjacent Tax Parcels 502200-10.-1-42 (2.11 acres) and -49.2 (2.43 acres) in the Town of Danby, Tompkins County. Both parcels front (total 492’) on Danby Road (NYS 96B). The town park road (Dotson Park Trail) forms the north and east boundary of #1839 and the east of #1849. Utilities: The area is served by electric and cable service. (Note: natural gas may exist but may not be available for new services.) Neither municipal sewer nor water are available so that properties are served by on-site individual sewage systems (OWTS) and private wells. Slope: The land slopes gently to the northeast from Danby Road. Current Use: #1839 is occupied by a 2-family dwelling with 6 bedrooms, plus an outbuilding. #1849 is occupied by a 4-unit apartment building with 6 bedrooms, plus two outbuildings. Projected Use: the owner is interested in redeveloping the property as a small commercial plaza with retail space and a small café or restaurant, and /or additional rental residential space. Needs for Further Investigation: • Contact the NYSEG, Spectrum cable, and Verizon to determine what level of services are available to this property. SENSITIVE ENVIRONMENTAL and HISTORIC FEATURES Most of the property is not affected by any sensitive environmental features. The NYS DEC Environmental Mapper indicates that the properties have no historic or archeological significance; are not within any Critical Environmental Area; and are not the subject of any environmental remediation. The Tompkins County Unique Natural Area (UNA-172) Danby Fir Tree Swamp is located several hundred feet east of these properties. The DEC search indicates that this property or nearby properties may be important to the threatened or endangered Northern Harrier. This probably applies mostly to the open and brushy areas off this property. A watercourse (but not an identified stream) flows through #1849, joining a tributary of Buttermilk Creek 2400’ to the northeast. This has been intercepted by the town park road and flows north along the town park road ditch to a catch basin on the NE corner of the property, where it continues to the tributary of Buttermilk Creek. No State or Federally regulated wetlands are identified on the property. Protected wetlands may exist east and north of the property. None of the property is in an Agricultural District. Needs for Further Investigation: • Request a formal response from NYS PR&HP about historical and archeological significance when a project is identified. • Investigate the presence or concern of the Northern Harrier. 3 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association ZONING The zoning on these parcels is LD, Low Density Residential. This zoning allows single/two-family homes on minimum 5 acre lots or lots with 200’ of frontage on public roads, or a cluster subdivision. Additionally, the Tompkins County Health Department (TCHD) has a minimum one- acre lot size in which a circle of 150’ diameter can fit where an OWTS is needed and municipal water is not provided. #1839 currently has a 2-family house and #1849 a 4-unit apartment. Additional uses in this zone may be allowed with special permit; re-zoning to High Density Residential, or Commercial Target Zone A, B, or C or Planned Development Zone. Smaller lot sizes may be accepted by the TCHD with engineered site plans showing compliance with separation distances between wells, OWTS and other features. Needs for Further Investigation: • Meet with Town officials to discuss types and density of development and requirement for re-zoning or special permit. SOILS The USGS Web Soil Survey identifies the following soils on the site: Type Description % of area Hydric %Slope HSG DPS HGW ErA Erie-Chippewa channery silt loam. Erie soil: typical profile: 0-38” channery silt loam; 38-72” channery loam. Somewhat poorly drained. 10-21” to restrictive feature of fragipan. Chippewa soil: typical profile: 0-72” channery silt loam. Poorly drained. 8-20” to restrictive feature of fragipan 100 No Yes 0-3 D 10-21” 8-20”’ 7-14” 0-6” HSG = Hydrologic Soil Group (A to D; A best drained and permeable; D the least) DPS = Depth of Permeable Soil HGW = Depth to Seasonal High Ground Water These soils have restrictions for development due to shallow permeable soil and shallow depth to groundwater. Hydric soils are typically wet, are an indicator of wetlands, are poor for OWTS and provide a poor base for structures or roads. Needs for Further Investigation: • Complete an on-site investigation of the soils with a backhoe to view soil profiles and perform percolation tests. SEWAGE TREATMENT No municipal collection system exists in the area so sewage must be managed by the project. All sewage must be treated before being discharged to the groundwater or a stream/watercourse. It is not likely that the NYS DEC will issue a State Pollutant Discharge Elimination System (SPDES) permit allowing discharge to the small watercourse that flows to Buttermilk Creek because a) it is not an identified stream and b) DEC’s policy is not to permit small (less than several thousand 4 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association gallons per day) discharges to surface water. Discharge to a watercourse is more involved (increased oversight, sampling, reporting) than discharge to the groundwater. Individual or clustered on-site wastewater treatment systems (OWTS) are therefore likely to be used. All OWTS need a Construction Permit from the Tompkins County Health Department, and a SPDES Permit from the NYS DEC if the design flow exceeds 1000 gpd (for any one system) or handles any waste (i.e., car wash, laundromat, brewery, manufacturing) except sanitary sewage. The ErA soil is not suitable for conventional absorption systems due to shallow permeable soils and shallow seasonal water. A septic tank followed by a raised system, possibly a raised absorption field, a mound, or a sand filter followed by downstream modified absorption trenches (DMAT) might be acceptable in the Erie soil. A pump is likely needed unless significant fill is placed around future buildings. Systems that serve parcels with different owners (such as a realty subdivision) must be operated by a Sewage Treatment District. If not owned by a municipality, the district must be formed with a Transportation Corporation and the municipality’s acknowledgment that it will be responsible for operations if problems arise. Systems designed for 1000 gpd or larger (more than 9 bedrooms) that discharge to the groundwater need to operate with a SPDES Permit and design standards are stricter than for smaller systems, resulting in taller raised systems or systems requiring larger areas. OWTS are generally designed based on 110 gallons per day per bedroom for residential use, 15- 25 gpd per person for offices or retail use, and 25-50 gpd per seat in a café/restaurant. A convenience store with a few seats and take-out coffee/snacks could have an OWTS design flow of 2000 gpd or more. Generally, the OWTS is placed downslope of buildings and wells. There must be a minimum of 100’ between any sewage absorption area and well, stream or watercourse. The separation distance increases to 200’ to a public water system well (serving 25 or more people or 5 or more connections {units}). The only area large enough to meet these restrictions is the northeast area of #1839 and the north-central area of #1849. There, between an existing well and the watercourse, a 1000 gpd OWTS might fit with a 12’ by 83’ sand filter followed by a DMAT in an area 80’ by 50’ with an equal replacement area available. Additional area could be gained by abandoning (having a well driller properly fill) the nearest well; then there may be space for a 2000 gpd OWTS, if soil conditions allow. It may be possible to redirect the watercourse so that it flows more directly into the park road ditch, thus increasing the area that is beyond 100’ from it. However, now that the watercourse has been incorporated into the road ditch, the 100’ buffer affects more area on the northeast portion of #1839. Also, if storm water must be treated on the property (see the STORM WATER MANAGEMENT section) the area available for OWTS may be greatly restricted. 5 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association There are at least two existing OWTS, one on each property to serve each building. Both systems may be reaching their life limit as they are at least 30 years old. A search of the TCHD records found no information about the OWTS serving #1839. An expansion or change-of-use of that building will likely result in the TCHD requiring a permit for a replacement OWTS (although the existing one might be allowed to remain in use for a time). A 6-bedroom OWTS, with water-saving fixtures, typically has a design flow of 660 gpd. The record of the OWTS serving #1849 shows a 1000-gallon tank followed by a 750-gallon septic tank, a 12’ by 75’ sand filter followed by a 6’ by 70’ Dispersion Trench, installed as a 900 gpd replacement system in 1988. All of this system appears to be within 100’ of the watercourse. It is likely that no change will be required if the building retains its current use, but any expansion or change-of-use will likely result in the TCHD requiring a permit for a replacement OWTS that meets the separation requirements. With water-saving fixtures, a 900 gpd OWTS can now serve up to 8 bedrooms. Estimated cost of abandoning a well is $500-2000; constructing a 1000-gpd OWTS $15-20,000 and a 2000-gpd OWTS $30-40,000, depending on the type of system and soil conditions. Needs for Further Investigation: • Identify potential uses of the property and resulting OWTS needs; discuss with TCHD. • Discuss with the TCHD whether the 100’ buffer applies to the park road ditch now that it contains the watercourse. • Consider if moving the watercourse is a practical way to increase area for OWTS. • Complete an on-site investigation of the soils with a backhoe to view soil profiles and perform percolation tests. • Discuss discharge to the watercourse with the NYS DEC if that is a preferred option. WATER SUPPLY No municipal water is available in the area; all properties have private systems. Building #1839 is served by a drilled well reported to be 60’ east of the building; Building #1849 is served by a drilled well next to the northwest corner of the building. This is reported to be 83’ deep. A third well may be present just off the NW corner of a shed just south of house 1839. No other information is available. A water system is lightly regulated if it is not a “Public Water System”. A PWS is one that serves 25 or more people, or 5 or more service connections. A PWS (despite Public in its name, a PWS may be privately owned) is required to operate with plans approved by the TCHD, continuously disinfect the water, and meet water quantity and quality parameters. Additional treatment and storage may be required. A non-PWS may have several non-interconnected well systems as long as each serves less than 5 connections (and less than 25 people) and the total connections are less than 15 (and less than 25 people total). The existing water system here, with two non-interconnected wells, one serving 2 connections and the other 4 connections, is not a PWS. The cost of upgrading or creating a PWS depends upon the quality of the untreated water, the peak and average demands of the system, and whether an existing building is available or a new 6 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association one needs to be built. The estimated cost to add disinfection to an existing system is $3-5,000. If storage and additional treatment is needed the cost could be $10,000 or more. A new drilled well could cost $5000 or more depending on the depth and amount of casing required. Needs for Further Investigation: • Discuss the possible number and types of services connected to, and the potential number of people served by, any one well or system with the TCHD. • Provide appropriate quantity (well yield tests) and quality analyses of the well water (consult with TCHD). • Determine if all existing wells will remain or if new ones need to be drilled to provide quantity or be protected from current or future OWTS. • Determine what treatment or storage requirements must be met. STORM WATER MANAGEMENT Certain construction projects require a Town approved Storm Water Pollution Prevention Plan (SWPPP) when more than 0.5 acre of soil is disturbed (uncovered by excavation, trenching, regrading, etc.). Fairly simple plans for controlling erosion and sedimentation (E&S) are required for up to 1 acre of disturbance. Unless the project consists of single family homes, if one or more acres are disturbed the project needs to be covered under the NY SPDES General Permit for Construction Activities Permit No. GP-0-15-002 with a Full SWPPP. A full SWPPP must show how the 1- 10- and 100-year storm flows will be detained and slowly released to protect downstream areas from erosion and flooding. The “first-flush” run-off from impermeable surfaces must be treated for quality prior to release. Existing drainage patterns must be maintained. Because detention ponds must also be placed at the lower elevations, they use space that might otherwise be used for the OWTS. Also, if a detention pond is designed for quality treatment and contains water year-round, any OWTS must be 100’ from it. Other practices for quality treatment may include rain gardens, grass filter strips, bio-retention filters, etc. A project on this property will be considered re-development and thus stormwater facilities may be significantly smaller than if the property was currently undeveloped. If the redevelopment results in the same or less rate or volume of run off than currently exists, no detention is required. This may be achieved if the impermeable area is not increased, and if drainage patterns remain. The current impermeable area on the two lots is approximately 23,000 square feet (0.53 acre). The impermeable area treated for quality may be as little as 25% of the impermeable area that currently exists. No costs can be estimated for storm water controls until the extent of needed controls is established. Needs for Further Investigation: • Field confirm the drainage areas and discharge points. • Determine how much soil disturbance is likely; determine what level of SWPPP is needed. • Manage the competing area needs between OWTS and storm water controls. 7 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association STATE ENVIRONMENTAL QUALITY REVIEW (SEQR) No matter what type of project evolves it will likely be subject to 6 NYCRR Part 17 State Environmental Quality Review (SEQR). An agency with approval authority must determination the environmental significance of the project during project review. Identified involved agencies may include the Town of Danby, the Tompkins County Health Department, and the NYS DEC if SPDES permits are required. Needs for Further Investigation: See the SENSITIVE ENVIRONMENTAL and HISTORIC FEATURES section SUMMARY OF NEEDS FOR FURTHER INVESTIGATION • Complete an on-site investigation of the soils with a backhoe to view soil profiles and perform percolation tests. • Field confirm the drainage areas and storm water discharge points. • Meet with Town officials to discuss types and density of development and requirements for re-zoning or special permit. • Meet with the TCHD to discuss OWTS: o identify potential uses of the property and resulting OWTS needs; o whether the 100’ buffer applies to the park road ditch now that it contains the watercourse. o if moving the watercourse is a practical way to increase area for OWTS. • Discuss a permitted discharge to the watercourse with the NYS DEC if that is a preferred option. • Determine how much soil disturbance is likely; determine what level of SWPPP is needed. • Manage the competing area needs between OWTS and storm water controls. • Meet with the TCHD to discuss water supply: o identify the possible number and types of water services connected to, and the potential number of people served by, any one well or system, to determine the level of water system regulation. o Determine and provide appropriate quantity (well yield tests) and quality analyses of the well water. o Determine if all existing wells will remain or if new ones need to be drilled to provide quantity or be protected from current or future OWTS. o Determine what drinking water treatment or storage requirements must be met. • Request a formal response from NYS PR&HP about historical and archeological significance when a project is identified. • Investigate the presence or concern of the Northern Harrier. • Contact the NYSEG, Spectrum cable, and Verizon to determine whether services are available to this property. 8 1839-1849 Danby Road Preliminary Site Review John M. Andersson, P.E. March 26, 2018 Professional Engineer license 51610-1 Registered in New York State Member American Society of Civil Engineers and American Water Works Association PROPERTY SKETCH Sketch from Tompkins County GIS showing contours, existing buildings, wells, OWTS, watercourse, etc. ATTACHMENTS 1. Short Environmental Assessment Form with NYS DEC Environmental Mapper report, partially completed by NYS DEC. WATERCOURSE HAS BEEN CUT OFF AND REDIRECTED NORTH EXISTING OWTS TOWN PARK ROAD ? WELLS (2 OR 3?) WITH 100’ BUFFER 100’ BUFFER TO WATERCOURSE EXISTING OWTS LOC UNK LOC LOC UNK POTENTIAL OWTS AREA ? W? W W GRAYED AREAS ARE POSSIBLE ADDT’L AREA FOR OWTS IF WELL & WATERCOURSE ARE MOVED POSSIBLE ADDT’L REDIRECTION OF WATERCOURSE GREEN AREAS ARE POSSIBLE AREAS FOR STORM WATER DETENTION. N