N.Y.C. Admin. Code § BC 3304: Section BC 3304: Soil and Foundation Work

3304.1 Scope.

The provisions of this section shall apply to all soil and foundation work, including but not limited to drilling or excavations made for the purposes of taking earth, sand, gravel, rock, or other material, as well as to soil and foundation work related to accessory uses such as garages, pools, and decks, and also to the underpinning or bracing of buildings or structures, in order to safeguard the public and property from such work. In addition to the requirements of this section, the applicable sections of Chapter 18 shall also apply to soil and foundation work.

Exceptions: This section shall not apply to:

1. Soil or foundation work not related to the underpinning or bracing of an existing building or structure, and which is performed in connection with utility or infrastructure work occurring within a public right of way, including but not limited to the construction, alteration, maintenance, repair, or demolition of bridges, streets, sidewalks, highways, railroads, subways, water tunnels, or utility lines.

2. Soil or foundation work on cemetery grounds for burials.

3. Soil or foundation work performed within an industrial or commercial quarry, plant, or yard and not related to the construction or demolition of a building or structure on the property of such quarry, plant, or yard.

3304.1.1 Measurements.

The depth of all soil and foundation work shall be measured from the level of the adjacent ground surface to the lowest point of the soil and foundation work. The height of all soil and foundation work shall be measured from the level of the adjacent ground surface to the highest point of the soil and foundation work. Where soil and foundation work occurs within a basement or cellar, the soil and foundation work shall be measured from the level of the adjacent slab.

3304.1.2 Safety of the public and property.

Soil and foundation work shall be performed and, as necessary, supported, in a manner to prevent injury to the public, damage to property, or collapse, subsidence, or uncontrolled loss of earth or rock.

3304.2 Permit.

A permit shall be obtained prior to the commencement of soil or foundation work when required by Chapter 1 of Title 28 of the Administrative Code.

3304.3 Notification.

Prior to the commencement of soil or foundation work, notification shall be provided as follows.

3304.3.1 Notification of the department.

No soil or foundation work within the property line shall commence unless the permit holder, or where there is no permit holder the person causing the soil or foundation work to be made, notifies the department, via phone or electronically, at least 24 hours, but no more than 48 hours prior to the commencement of such work. The notification shall state the date that such soil or foundation work is to commence and include a "Call before you dig" confirmation number verifying compliance with the notification requirements of Section 3304.3.7. Should the notification date fall on a weekend or official holiday, the permit holder, or where there is no permit holder the person causing the soil or foundation work to be made, shall notify the department on the last business day before the commencement date.

In the event that the soil or foundation work does not begin on the date provided in the notification to the department, the permit holder, or where there is no permit holder the person causing the soil or foundation work to be made, shall notify the department of its cancellation not more than 24 hours prior to but no later than the date for which the soil or foundation work was scheduled. Should the cancellation date fall on a weekend or an official holiday, the permit holder, or where there is no permit holder the person causing the soil or foundation work to be made, shall notify the department on the next business day after the intended commencement date. The permit holder, or where there is no permit holder the person causing the soil or foundation work to be made, shall notify the department of a new intended commencement date pursuant to the provisions above.

Exceptions: Notification to the department is not required for the following:

1. Hand excavation work that extends less than 5 feet (1524 mm) in depth and is 2 feet (610 mm) or more from an existing footing or foundation. This exception shall not apply to any hand excavation work performed anywhere in existing or demolished basements or cellars that adjoin existing foundations.

2. Excavations for a geotechnical investigation that do not exceed 10 feet (3048 mm) in length, width, or diameter, and that are conducted under the supervision of a registered design professional.

3. Emergency work performed by the Department of Housing Preservation and Development (HPD) or other agency as directed by the commissioner or work on unsafe buildings performed by HPD or other agency pursuant to a precept.

4. Soil or foundation work related to gardening or landscaping work, provided no excavation occurs to a depth of 5 feet (1524 mm) or greater; and either:

4.1 The excavation occurs more than 5 feet (1524 mm) from all footings and foundations; or

4.2 Where the excavation occurs within 5 feet (1524 mm) or less from a footing or foundation, such excavation does not occur below the level of the footing or foundation.

5. Soil or foundation work related to the pouring of a slab or pavement, provided no excavation to a depth greater than 2 feet (610 mm) occurs in conjunction with such work.

6. Where notification is required by Section 3306.3, separate notification for the removal of a foundation is not required.

3304.3.2 Notification of adjoining property owners.

When an excavation to a depth of 5 feet to 10 feet (1524 mm to 3048 mm) is to be made within 10 feet (3048 mm) of an adjacent footing or foundation, or when any excavation over 10 feet (3048 mm) is to be made anywhere on a site, the person causing the excavation to be made shall provide written notice to the owners of the adjoining property not less than 10 days prior to the scheduled starting date of the excavation. The written notice shall provide a description of the work to be performed, the timeframe and schedule, the contact information of the person causing the excavation to be made, and the contact information of the department.

Exception: Notification is not required where the excavation is set back from the edge of the adjacent footing or foundation or adjoining property by a ratio of 2 horizontal to 1 vertical, as measured from the deepest point of the excavation.

3304.3.3 Notification to the Department of Environmental Protection.

Whenever soil or foundation work, for any purpose, is proposed to a depth greater than 50 feet (15 240 mm) in the borough of the Bronx or on or north of 135th Street in the borough of Manhattan, or greater than 100 feet (30 480 mm) in the borough of Brooklyn, Queens, or Staten Island or south of 135th Street in the borough of Manhattan, the owner of the premises, engineer, architect or contractor shall notify the New York City Department of Environmental Protection prior to commencement of such activity in accordance with Section 24-367 of the Administrative Code and any rules promulgated thereunder. The issuance of any permit or approval by the department shall not relieve the applicant, owner, engineer, architect or contractor of the obligation to comply with any notification or permitting requirements of the New York City Department of Environmental Protection. Whether or not a permit is required from the department for work, including but not limited to drilling for borings or geothermal wells, the owner of the premises, engineer, architect or contractor shall still comply with the notification and permitting requirements of the New York City Department of Environmental Protection.

3304.3.4 Excavations requiring permit from the New York State Department of Environmental Conservation.

Whenever soil or foundation work is planned deeper than 500 feet (152 m) below grade, a permit may be required from the New York State Department of Environmental Conservation. The issuance of any permit or approval by the department shall not relieve the applicant of the obligation to comply with any approval or permitting requirements of the New York State Department of Environmental Conservation. Whenever any drilling for borings or geothermal wells is planned, the owner of the premises or the contractor shall notify the New York State Department of Environmental Conservation prior to commencement of such activity to determine if a permit is necessary.

3304.3.5 Notification and approval of the New York City Transit Authority, the Metropolitan Transportation Authority, and the Port Authority of New York and New Jersey.

Whenever an excavation of any depth is proposed within 200 feet (60 960 mm) of any facility, infrastructure, or property under the jurisdiction of the New York City Transit Authority, the Metropolitan Transportation Authority, or the Port Authority of New York and New Jersey, including but not limited to rail and subway lines, stations, station entrance and access points, bridges, tunnels, bus depots, access roads, fan plants, pump rooms, substations, shops and yards, duct lines, and easements, an approval shall be obtained from such authority having jurisdiction. The owner of the premises or the contractor shall notify the authority having jurisdiction prior to commencement of any such activity. The issuance of any permit or approval by the department shall not relieve the applicant of the obligation to comply with any approval requirements of the New York City Transit Authority, the Metropolitan Transportation Authority, or the Port Authority of New York and New Jersey.

3304.3.6 Notification and permit requirements of the New York City Fire Department.

Soil or foundation work that is to be done with the use of explosives shall also be subject to the notification and permit requirements set forth in the New York City Fire Code.

3304.3.7 Call before you dig notification.

"Call before you dig" notification shall be provided in accordance with the requirements of 16 NYCRR Part 753. The notification must address all street frontages associated with the soil and foundation work.

3304.4 Protection of sides of excavations.

The sides of excavations shall be protected in accordance with the requirements of Sections 3304.4.1 through 3304.4.6.

3304.4.1 Support of excavation construction documents.

Means of supporting excavations, including related or resulting embankments, rock faces, and soil slopes, shall be indicated on construction documents. Such means of supporting excavations shall be installed and maintained in accordance with the construction documents. The construction documents shall be prepared by a registered design professional who has demonstrated knowledge or experience in the design of retaining structures or bracing systems for the support of excavation. Where the excavation exceeds 20 feet (6096 mm) in depth, the registered design professional shall be a New York State licensed professional engineer.

Exceptions: Construction documents indicating the means of supporting the excavation are not required if:

1. The excavation meets the conditions specified in Items 1.1 through 1.4:

1.1. Is less than 5 feet (1524 mm) in depth;

1.2. Occurs above the level of the water table;

1.3. Occurs more than 5 feet (1524 mm) from all streets, sidewalks, tunnels, railroad tracks, public right of ways, and retaining walls; and

1.4. Occurs either:

1.4.1. More than 5 feet (1524 mm) from all footings and foundations; or

1.4.2. When within 5 feet (1524 mm) or less from a footing or foundation, does not extend below the level of the footing or foundation.

2. The excavation meets the conditions specified in Items 2.1 through 2.3:

2.1. Occurs more than 5 feet (1524 mm) from all footings, foundations, streets, sidewalks, tunnels, railroad tracks, public right of ways, and retaining walls;

2.2. Does not exceed 20 feet (6096 mm) in depth; and

2.3. Either:

2.3.1. The slope of the excavation does not exceed 1.5 horizontal to 1 vertical (34 degrees measured from the horizontal), with no benching allowed; or

2.3.2. A registered design professional determines the soil type, and the excavation is properly sloped or benched for the soil type in accordance with the requirements of Section 3304.4.2. Determination of the soil type shall be based upon a site specific evaluation, and documentation of the determination, signed and sealed by the registered design professional, shall be kept at the site.

3. A trench box is utilized in accordance with the manufacturer's specifications, provided a physical copy of the manufacturer specifications are available onsite.

4. It is a trench that complies with Table 3304.4.1, including all notes to the table.

5. The excavation is performed in conjunction with the installation or removal of an exterior in-ground pool, provided such pool is an accessory to a one-or two-family home, is limited to 400 square feet (121.92 m

2

) in area, and further provided that the distance from the edge of the pool to any building, structure, or lot line is greater than the depth of the deepest portion of the pool.

6. Where demolition drawings are required by Section 3306.5, separate support of excavation construction documents for the removal of the foundation are not required, provided the details required for a support of excavation drawing are instead shown on the demolition drawings.

Table 3304.4.1 Minimum Sizes of Timber Bracing and Timber Sheet Piling for Trenches Not Exceeding 10 Feet (3048 mm) in Depth and 15 Feet (4572 mm) in Width

Depth of trench

Width of trench

Nominal size of cross bracing at 6 feet (1829 mm) horizontal spacing

Shoring

Up to 10 ft (3048 mm)

Up to 9 ft (2743 mm)

6 in x 8 in (152 mm x 203 mm)

Sheet Piling, 2 in x 6 in (51 mm x 152 mm), spaced tight, and Wales, 12 in x 12 in (305 mm x 305 mm), with 5 ft (1524 mm) maximum vertical spacing

Up to 15 ft (4572 mm)

8 in x 8 in (203 mm x 203 mm)

Notes to Table 3304.4.1:

1. All timber or equivalent substitute to have bending strength of 850 psi or above.

2. The depth of the trench shall be considered the depth from top of grade, not top of shoring structure should a portion of the support of excavation be by benching or sloping methods.

3. Table shall not be utilized if any of the following are met:

a. Trench exceeds the specified dimensions.

b. Stored material or structures are present within a distance equal to the depth of the trench.

c. Equipment surcharge loading exceeds 20,000 lb (9071.85 kg).

d. Surcharge load exceeds 2 ft (610 mm).

e. Cross bracing is subject to any vertical load that meets or exceeds a load equivalent to a 240-lb (109 kg) gravity load distributed over a 12 in (305 mm) section of the center of the bracing member.

3304.4.1.1 Content of support of excavation construction documents.

Support of excavation construction documents shall, at a minimum:

1. Be specific to the site;

2. Be fully dimensioned;

3. Account for the entire scope of work;

4. Indicate all items required by Section 107.8;

5. Indicate soil or rock type and bearing capacity;

6. Indicate the water table elevation;

7. Indicate if dewatering is needed, and if a dewatering plan is required by Section 3303.14.5, note that a dewatering plan is required and the depth at which the dewatering plan must be put into effect. Further, where a dewatering plan is required by Section 3303.14.5, note the depth at which work must stop if a dewatering plan has not been provided; such depth must be equal to or shallower than the depth specified for the dewatering plan to be put into effect;

8. Indicate the support of excavation, including but not limited to sloping, benching, sheeting, shoring, and bracing;

9. For an excavation in rock, any supplemental support of the rock face;

10. Indicate all structures, utilities, infrastructure, and subsurface structures impacted by the soil or foundation work;

11. Indicate the design load imposed for temporary construction installations, material, and equipment, including but limited to sidewalk sheds, scaffolds, runback structures, cranes, excavators, and stored or piled material, and note that all temporary construction installations or equipment that will impose a load on the support of excavation in excess of the design load imposed must be reviewed for acceptability by the designer of the support of excavation;

12. Indicate the sequence of the excavation operation and the installation and removal of the support of excavation, including all relevant phasing, and including the depth at which support of excavation must be installed;

13. Account for the provisions of Section 3304.4.5;

14. Reference the monitoring plan, where a monitoring plan is required;

15. Specify required inspections and inspection intervals for the support of excavation, including special inspections; and

16. Where slurry is utilized to support the excavation, the information required by Section 3304.12 shall also be indicated.

3304.4.1.2 Geotechnical analysis and relevant reports.

The support of excavation construction documents shall be developed based upon site specific testing and analysis performed by a registered design professional who has demonstrated knowledge or experience in geotechnical evaluation. The support of excavation construction documents must incorporate all the conditions and findings identified in the geotechnical report required by Section 1803.6, the evaluation analysis required by Section 1817, and the preconstruction survey required by Section 3309.4.3.

3304.4.2 Limitation on sloping and benching.

Where sloping or benching is utilized to support an excavation, the slope or bench step shall be appropriate for conditions at the site, including but not limited to soil type, environmental conditions, and surcharge loads. In no case shall the maximum slope or bench step for an excavation that is 5 feet (1524 mm) or greater in depth exceed the values specified in Table 3304.4.2. For layered soil conditions, the most restrictive value among the soil types present at the excavation location shall be utilized unless otherwise specified by the registered design professional and indicated on the construction documents required by Section 3304.4.1.

Exception: The limitations of Table 3304.4.2 shall not apply to excavations made in Class 1a, 1b, or 1c rock, as classified by Chapter 18, provided the geotechnical report required by Section 1803.6 substantiates the safety of the proposed slope, cut, or bench step, and further provided that the resulting slope, cut, or bench step, as well as any supplemental support of the rock face, is indicated on the construction documents required by Section 3304.4.1.

Table 3304.4.2 Maximum Allowable Slopes and Steps

Soil Type

Maximum Allowable Slopes (Horizontal: Vertical)

Maximum Allowable Bench Step

Type A soil

1:1 (45º)

5 feet (1524 mm)

Type B soil

1:1 (45º)

4 feet (1219 mm)

Type C soil

1 1/2:1 (34º)

Not allowed

3304.4.3 Fence.

Every site with an excavation shall be enclosed with a fence that meets the requirements of Section 3307.7.

3304.4.4 Guardrail system.

All open edges of an excavation that are 6 feet (1829 mm) or greater in depth shall be protected by a guardrail system meeting the requirements of Sections 3308.7.1 through 3308.7.5, or by a solid enclosure at least 3 feet 6 inches (1067 mm) high. For the purpose of a guardrail system installed in accordance with this section to protect the open edge of an excavation, the term "floor" in Sections 3308.7.1 through 3308.7.5 shall mean "ground."

Exceptions:

1. A toeboard is not required where the sheeting, shoring, bracing, or any other support of excavation extends at least 3 1/2 inches (89 mm) above the top of the excavation.

2. A guardrail system or a solid enclosure is not required where access to the adjoining area is precluded.

3. A guardrail system or a solid enclosure is not required where side slopes are three horizontal by one vertical (33-percent slope) or flatter.

4. In lieu of a guardrail system, wells, pits, excavation shafts, or similar excavations may be protected by an adequate cover capable of supporting, without failure, at least twice the weight of persons, equipment, and materials that may be imposed on the cover at any one time, or where located in roadways and vehicular aisles, at least twice the maximum axle load of the largest vehicle expected to cross over the cover. The cover shall be secured when installed so as to prevent accidental displacement by the wind, equipment, or persons, and shall be color coded or marked with the word "HOLE" or "COVER" to provide warning of the hazard.

5. The edges of ramps shall be protected in accordance with Section 3315.

3304.4.4.1 Openings.

To provide necessary openings for intermittent operations, one or more sections of the guardrail system or solid enclosure may be hinged or supported in sockets. When supported in sockets, rails shall be so constructed that they cannot be jolted out. A button or hook may be used to hold the guardrail system or solid enclosure in a fixed position. As an alternative to hinged or socketed sections, substantial chains or ropes may be used to guard such openings in such guardrail system or solid enclosure. Where so used, the chains or ropes shall meet the tautness and height requirements as the rails of a standard guardrail system.

3304.4.5 Placing of soil or foundation work equipment and excavated material.

Excavated material and superimposed loads, including but not limited to equipment and trucks used for soil or foundation work, shall not be placed closer to the edge of the excavation than a distance equal to one and one-half times the depth of such excavation unless the sides of the excavation have been sloped or sheet piled (or sheeted) and shored to withstand the lateral force imposed by such superimposed loads, or the registered design professional has determined the side of the excavation can adequately support the load imposed, with such support or determination shown on construction documents required by Section 3304.4.1. In the case of open excavations with side slopes, the edge of excavation shall be taken as the top of the slope.

3304.4.6 Installation of protection.

Required protection for the sides of the excavation shall be installed as the excavation advances. The placement of permanent structures or fill in areas requiring support of excavation shall not begin until the support of excavation has been completed for such areas.

3304.5 Inspections.

Soil and foundation work shall be inspected in accordance with the requirements of Sections 3304.5.1 and 3304.5.2.

3304.5.1 Rainstorms.

All sides or slopes of excavations or embankments shall be inspected after rainstorms, or any other hazard-increasing event, and safe conditions shall be restored.

3304.5.2 Special inspections.

Special inspections shall be performed in accordance with Chapter 17.

3304.6 Retaining walls.

The requirements of Article 305 of Title 28 of the Administrative Code, as well as Sections 1806 and 3309 of the building code shall apply as applicable.

3304.7 Access.

Every excavation shall be provided with at least one safe means of ingress and egress that is kept available at all times. For a trench that has a depth of 4 feet (1219 mm) or greater, and with a width of 15 feet (4572 mm) or less, as measured between the soil, forms, or structure at the bottom of the trench, one or more stairways, ladders, ramps, or other safe means of ingress and egress shall be located in the trench so as to require no more than 25 feet (7620 mm) of lateral travel.

3304.8 Drainage.

The requirements of Section 3303.14 shall apply.

3304.9 Utilities.

The requirements of Section 3303.2 shall apply.

3304.10 Dewatering.

The requirements of Section 3303.14 shall apply.

3304.11 Underpinning requirements.

The requirements of Section 1814 and Section 3309 shall apply.

3304.12 Slurry.

Where slurry is utilized to support an excavation, trench, or drilled or bored hole, slurry mix proportions and installation procedures shall be provided by a registered design professional on signed and sealed design and installation procedures. The installation procedures shall account for all imposed loads, including those from the earth, adjacent structures, and adjacent equipment. Where construction documents are required for the support of excavation by Section 3304.4.1, slurry mix proportions, slurry installation procedures, and slurry parameters necessary for stability, including but not limited to viscosity, unit weight, fluid loss, sand content, and pH, shall be indicated on such construction documents. The use of slurry to support excavations shall be subject to special inspection in accordance with Chapter 17.