Photo by Shawn Winsor Frog in Pond Section 4. Environmental Inventory & Analysis 4. A. Geology, Soils, and Topography Lancaster is located along the eastern margin of the Central Upgrade region of Massachusetts, a region of moderate relief characterized by numerous, irregularly shaped granite hills, plains, and glacial features known as monadnocks. Throughout the region, forests are interspersed with wetlands, ponds, lakes, rivers, and streams. Where the North Nashua and South Nashua Rivers join in Lancaster at “The Meeting of the Waters”, the main stem of the Nashua flows northward at an elevation of 220’ above mean sea level. To the north and west, rolling hills reach elevations of more than 550 feet. This area is highly conducive to rapid runoff. The Wisconsin Glacier of the Pleistocene epoch, which ended approximately 12,000 years ago, was the last major advance in North America of the Laurentide ice sheet which radically changed the landscape. Two miles thick in places, it caused drumlins to be formed by riding over loose bedrock and, as it melted and by dumping boulders, stones and soils along its southerly receding face. Called glacial till, this heterogeneous material covers much of the landscape in Worcester County. Glacial outwash was formed by melt water from the receding glacier picking up glacial till, sorting it by size and water velocity, and redepositing it downstream. The region surrounding the Nashua River Valley is an example of this outwash plain. Alluvium, made up of sand, silt, or clay, was deposited upon the land by streams. Areas of glacial till generally range from gently sloping to strongly sloping. Glacial outwash has less relief. Lancaster’s bedrock is low-grade, metamorphic rock of the Nashua belt and Worcester formations. The town sits in the Nashua Valley and the Glacial Lake Nashua. Lake Nashua 4-1 extended over the drainage area of Boylston to Pepperell and is the largest of its kind east of the Connecticut Valley. Generally speaking, the most productive aquifers in our larger Nashua River basin are the sand and gravel deposits located in low-lying areas near surface water bodies. Many of the soils in Lancaster are moderately to highly permeable, so it is important that the Open Space and Recreation Plan address aquifer protection. Much of the underlying bedrock is exposed on hillsides and summits of the area and is oriented north to south. Glacial till deposits cover approximately 30% of the town. Alluvium deposits underlie most of the Nashua and its stems here in Lancaster. Alluvium is sediment deposited by flowing water. Map 4 titled “Soils and Geologic Features” is in the appendix. There are five major soils here in Lancaster: • Hinckley-Merrimac-Windsor o Very deep, nearly-level-to-steep soils (slope 35%) that are excessively drained and somewhat excessively drained; on outwash plains. • Paxton-Woodbridge-Canton o Very deep, nearly level to steep soils (slope 35%) that are well drained and moderately well drained; on uplands. Soils are suitable for farming although erosion can be a problem. • Chatfield-Hollis Series o Moderately deep and shallow, gently sloping to moderately steep soils (slope 25%) that are well drained or somewhat excessively drained; on uplands. These soils tend to be on hills and ridges with areas of rock outcrop. There is generally a shallow depth to bedrock. • Quonset Series o Very deep, excessively drained soils on stream terraces, eskers, kames, and outwash plains. A kame is a hill of sorted and layered gravel and sand, deposited in openings in stagnating or retreating glaciers. These soils formed in glacial outwash and are nearly level to steep slopes (slope 25%). They are on the level with the Hinckley series (acidic, high permeability, low nutrient) but have more gravel in the upper 40 inches. • Winooski-Limerick-Saco o Very deep, nearly level soils (slopes up to 3%) that are moderately well drained, poorly drained, and very poorly drained, on flood plains. These soils are suitable for farming although seasonable flooding and high water table can be a significant problem. This soil is a poor filter for septic tank absorption fields. Soil Diversity Lancaster has a rich soil heritage which is ours to safeguard for the use and benefit of future generations and which defines the scenic character of our town with its hilltops, ridges, flood plains, cultivated fields, and forests. As Lancaster becomes incrementally built up, we see the interconnectedness of the environment and human well being. We are as dependent upon the soil as we ever were. While private property remains as such, there is the increasing dilemma of the stewardship of the natural resources that belong to us all. 4-2 Prime farmland is one of several kinds of farmland defined by the United States Department of Agriculture (USDA) as of major importance for the nation’s long range needs of food and fiber. The supply of prime farmland is limited. Wise use by local governments must be encouraged. The recent trend is the loss of prime farmland to residential, industrial and commercial uses. Loss of prime farmland puts pressure on more marginal lands. The USDA updated its soil survey for Lancaster in 1985 (as part of Worcester County, Northeastern Part) and lists soil units that make up prime farmland. (This table can be referenced in the expanded Environmental Inventory & Analysis section 4.0 in the appendix.) Mass Audubon’s landmark “ Losing Ground” was updated in May of 2009 and evaluated data from the period 1999-2005. While land conversion to development slowed during this time, general ecosystem functioning and resiliency to change degraded significantly. The landscape during the period 1999-2005 was severely threatened by fragmentation of large forested blocks of land and by the steady conversion of prime agricultural land to development. The towns that see the greatest indirect impacts from development are the towns that have the largest intact blocks of agricultural land and of forested uplands and forested wetlands remaining in the State. According to the May 2009 “Losing Ground” edition, Lunenburg and Groton were among the top 20 towns in the Commonwealth for loss of agricultural land to development. Clinton, Lunenburg, Shirley and Bolton were developed at a faster rate than Lancaster. However, in the 2003 “ Losing Ground” edition, Lancaster had the distinction as a “sprawl hotspot”, third on the top 20 list for, “Communities ranked by acres consumed per new housing unit”. Today, Lancaster is embedded within what Mass Audubon identifies as “the sprawl danger zone”, defined as “where development pressure is increasing and significant ecological impacts have occurred yet significant regional conservation opportunities still exist.” It is the trend within the Commonwealth that towns with relatively little remaining agricultural lands do a better job of protecting them for agriculture than towns that have a large amount of agricultural lands, as does a town like Lancaster. Much of our agricultural lands are unprotected. Farmers and owners of agricultural lands need tangible financial incentives not to sell their land for development. According to Mass Audubon, towns in the “sprawl danger zone” such as Lancaster deserve the State’s attention for limited funding of conservation initiatives because they still maintain significant biodiversity but are under extraordinary development pressure. Hopefully, this will work in our town’s favor as we solicit State funds for local conservation and for land preservation initiatives. The May 2009 Losing Ground update included a map of the top twenty towns in the state experiencing loss to agricultural land to development in the period between 1999 and 2005. While Lancaster was not on this map, the surrounding towns of Groton and Lunenburg were. Soils affect the kind of vegetation that is available to wildlife for food and cover and it affects the structure of water impoundments. The biodiversity of our flora and fauna is ultimately dependent upon the biodiversity of the soil. Soils that are attractive for earth products removal can also unique and attractive for certain types of natural communities, those that depend upon droughtiness, high soil permeability, low nutrient value, and brushy and bare vegetative cover. Many species of Lepidoptera (moths and butterflies) that are systematically declining in the Commonwealth need this type of habitat and several species of threatened turtles also thrive in this sandy soil environment. Because many turtles do not reach sexual maturity until upwards of 15-17 years and live in excess of 70 years, changes to their environment making their habitat 4-3 unsuitable can have disastrous effects on adult population viability. Many declining bird species thrive in the sparse cover and brushland environment of the Pitch Pine/Scrub Oak communities that are often endemic to sandy outwash plains. The Natural Heritage & Endangered Species Program (NHESP) has designated portions in Lancaster of Wekepeke Hill (area abutting Jungle Road and extending in to Sterling, through which the Wekepeke brook flows, a coldwater fishery) and of the Pine Hill area as Priority Habitat and Estimated Habitat for Rare Species, as well as much of the South Post of Fort Devens. MassWildlife purchased land in the Pine Hill area within the last 5 years, extending the acreage of the Bolton Flats Wildlife Management Area. MassWildlife has expressed an interest in the 35 acre town owned parcel in this area that links to MassWildlife parcels and which represents an intact Pitch Pine/Scrub Oak community. As this entire block of habitat includes rare and declining natural communities and connects the Oxbow National Wildlife Refuge and the Bolton Flats WMA, literally thousands of acres, MassWildlife has a strategic plan to preserve the Pine Hill area, if possible. This excerpt from the May 6, 2009 NHESP Open Space and Recreation Plan letter says, “Lancaster is one of the towns with town wide maps showing areas forested in the 1830s, areas of possible Primary Forest, most of which were untilled woodlots and wooded pastures (areas shown on map which is in appendix section).