Table of Contents

Introduction 
Amendments to the Zoning Ordinance 
 
Amendments to the Subdivision and Land Development Ordinance

Article I. Definitions 
Article II. Procedures for Subdivision and Land Development Approval 
Article III. Plan Requirements 
Article IV. Design Standards

Amendments to the Subdivision and Land Development Ordinance 

Article I. Definitions 

The following terms should be added to the definition section of the subdivision and land development ordinance. 

Feeder Roots—Feeder roots are the smallest roots of a tree, which are responsible for most of the absorption of nutrients into the tree; most are located within the top twelve inches of the soil. 

Municipal Arborist—Selected by the municipality a municipal arborist is responsible for ensuring that the tree protection standards are followed correctly. The municipal arborist must have a degree in arboriculture, horticulture, forestry, landscape architecture, silviculture, or plant physiology and have a knowledge of and experience in the methods of tree protection. 

Pruning—Pruning is the removal of branches from a tree using proper tools and approved cutting techniques. 

Tree Dripline—The tree dripline is the line marking the outer edges of the branches of the tree. 

Tree Protection Zone (TPZ)—The TZP is an area that is radial to the trunk of a tree in which no construction activity shall occur. The tree protection zone shall be 15 feet from the trunk of the tree to be retained, or the distance from the trunk to the dripline, whichever is greater. Where there is a group of trees or a woodlands, the tree protection zone shall be the aggregate of the protection zones for the individual trees. 

Woodlands—One-quarter acre or more of wooded land where the largest trees measure at least 6 inches diameter at breast height (dbh) or 4.5 feet from the ground. The woodland shall be measured from the dripline of the outer trees. Woodlands are also a grove of trees forming one canopy where ten or more trees measure at least 10 inches diameter at breast height (dbh). 

Article II. Procedures for Subdivision and Land Development Approval 

The following amendments shall be made to the procedures section of the ordinance. 

Any plan containing existing trees that are proposed to be protected/saved shall be submitted to and reviewed by the municipal arborist. 

Article III. Plan Requirements 

The following amendments should be included within the preliminary plan requirement section of the ordinance. 

Natural Features Map 

Should contain the following information: 

A. Floodplain areas—The portion of the land, if any, within the floodplain district of the municipality and the identification of the land with floodplain district which shall include areas subject to inundation by waters of the 100-year flood. The basis for the delineation of this district shall be the current flood insurance study for the municipality prepared by the Federal Insurance Administration. In those areas of the municipality which are not included within the aforementioned Flood Insurance Study, the floodplain district shall be defined as that area including all soils mapped by the Soil Survey of Bucks and Philadelphia Counties, Pennsylvania prepared by the Soils Conservation Service, as alluvial soils, including but not limited to Alluvial Land (Ae) Alton Gravely loam, flooded (AIA); Bowmansville silt loam (Bo); Hatboro Silt Loam (Ha); Marsh (Mh); Pope loam (Poa) and Rowland silt loam (Ro); 

B. Floodplain soil areas; 

C. Slope areas; 

1. 0 to 15 percent 

2. 15 to 25 percent 

3. 25 percent and over 

D. Location of woodland areas and the location of individual trees; 

E. Water courses; 

F. Lakes and ponds; 

G. Wetlands; 

H. Wetland margin; 

I. Rock outcroppings; 

J. The boundaries of the various soil types and identification key as indicated in the Soil Survey of Bucks and Philadelphia Counties, Pennsylvania, with a description of each soil type; 

K. The location of all trees to be saved, including their trunk and dripline locations. Driplines should be plotted accurately, to scale. When groups of trees are to be saved only the locations of the trees on the perimeter must be shown; 

L. The tree protection zone (TPZ); 

D. The location of proposed retaining walls around trees; 

E. Construction details of all retaining walls, including special soil and fill mediums where applicable. Any grade changes which would alter surface and/or subsurface water movement either to or from the tree protection zone. 

F. A preliminary regrading plan which illustrates all disturbance of the identified natural feature areas. The amount of each natural feature disturbed shall be indicated and illustrated on the resource protection map. 

Article IV. Design Standards 

The following provisions shall be added to the design standards of the ordinance. 

Tree Protection Standards 

A. General Requirements 

1. Grade changes and excavations shall not encroach upon the tree protection zone (TPZ); 

2. No toxic materials shall be stored within 100 feet of a tree protection zone, including petroleum based and/or derived products; 

3. The area within the TPZ shall not be built upon, nor shall any materials be stored there either temporarily or permanently. Vehicles and equipment shall not be parked in the TPZ; 

1. When tree stumps are located within ten feet of the tree protection zone, the stumps shall be removed by means of a stump grinder to minimize the effect on surrounding root systems; 

2. Tree roots which must be severed shall be cut by a backhoe or similar equipment aligned radially to the tree. This method reduces the lateral movement of the roots during excavation, which if done by other methods could damage the intertwined roots of adjacent trees; 

3. Within four hours of any severance of roots, all tree roots that have been exposed and/or damaged shall be trimmed cleanly and covered temporarily with moist peat moss, moist burlap, or other moist biodegradable material to keep them from drying out until permanent cover can be installed; 

4. Sediment, retention, and detention basins shall not discharge into the tree protection zone; 

5. Sediment, retention, and detention basins shall not be located within the tree protection zone. 

C. Retaining Walls 

1. When the original grade can not be retained at the tree protection zone line, a retaining wall shall be constructed outside of the tree protection zone; 

2. The retaining wall shall be designed to comply with the municipal standards for retaining walls; 

3. In addition, the following methods shall be used to ensure survival of the tree; 

a) The top of the wall shall be 4 inches above the finished grade line; 

b) The wall shall be constructed of large stones, brick, building tile, concrete blocks, or treated wood beams not less than 6 inches by 6 inches; a means for drainage through the wall shall be provided so water will not accumulate on either side of the wall; weep holes shall be required with any wall; 

c) Any severed roots as a result of excavation shall be trimmed so that their edges are smooth and are cut back to a lateral root if exposed; 

d) A layer of clean stone (sized ¾ to 1 inch) shall be placed one foot out from the wall to aid in drainage. 

D. Pruning Methods—All final cuts shall be made sufficiently close to the trunk or parent limb but without cutting into the branch collar or leaving a protruding stub, according to the National Arborist Association standards. All necessary pruning cuts must be made to prevent bark from being torn form the tree and to facilitate rapid healing. Flush cuts are unacceptable. 

E. Fertilization Methods 

1. All trees which have experienced any disturbance or have had damages to the roots or branches shall be fertilized; 

2. Trees shall be fertilized in early fall (September-October) or mid-spring (April-May). Fall applications are preferred; 

3. Fertilizer shall be broadcast over the soil surface in an area twice the size of the tree protection zoned at the rates given in 5. Below. A minimum of 1,000 square feet per tree will receive fertilization; 

4. Fertilizer grade shall have approximately 3 parts nitrogen to 1 part phosphorus and potassium (3-1-1 ratio); 

5. Fertilizer shall be applied at a rate equivalent to 1 pound nitrogen per 1,000 square feet. 
 

Example	How much 20-8-8 fertilizer needed to apply 1 pound  nitrogen over 1,000 square feet
	Need 1 lb. Nitrogen
	0.20 x = 1
	x = 1
	20
	x =5 lbs.
	5 lbs. 20-8-8 should be broadcast over a 1,000-square-foot area.

F. Trenching and Tunneling 

1. If there is no alternative but to locate a utility line through a TPZ, tunneling shall be used instead of trenching, except where in the opinion of the municipal arborist, survival of the tree would not be affected by either method. The municipal arborist shall determine the most desirable location for the utility line; 

2. Trenches shall be filled as soon as possible and tamped lightly to avoid air spaces.

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