Underground Utility Estimating & Takeoff Services
Underground utility takeoff services for US civil contractors bidding water, sanitary sewer and storm drainage packages. Review pipe lengths, structures, trench quantities, bedding, backfill and restoration against your issued drawings. Request quantities for your own rates or a separately quoted priced estimate.
- Storm Drainage: RCP, HDPE, PVC pipes, catch basins, headwalls
- Sanitary Sewer: SDR-26/35 gravity mains, precast manholes, laterals
- Water Systems: C900 PVC / Ductile Iron, valves, hydrants, services
- Trench Stratification: 0-6', 6-10', 10-14', and 14'+ depth brackets
- Bedding & Backfill: Crushed stone bedding tons & select fill CY
Get a utility takeoff matched to your tender
Send your utility plans, profiles and bid schedule. Confirm the systems, depth brackets and output format you need in one written scope.
Agree what you receive
- Pipe runs grouped by system, size and material, with structures and fittings identified from the supplied documents.
- Trench excavation, bedding, backfill and restoration measured separately where installation details are available.
- An agreed quantity schedule and drawing references. Labor, equipment and material pricing are included only when requested and quoted.
Send the documents for a quote
Utility layouts and profiles, structure schedules, trench and bedding details, specifications, addenda, project location and bid deadline.
Tell us whether you need quantities for your own rates or a priced estimate. Incomplete drawings, alternates and later revisions are identified in the proposal.
An underground site utility takeoff is the comprehensive quantification of all subterranean infrastructure systems governed by CSI MasterFormat Division 33. This includes wet piping systems (sanitary sewer gravity lines, water distribution mains, and storm drainage networks) and dry conduits (electrical power and telecommunications duct banks). An engineering-grade takeoff segments piping by diameter, pipe class, and bid depth brackets (0-6', 6-10', 10-14', 14'+), while calculating structure heights (rim to lowest invert), bedding aggregates (ASTM C33 sand or #57 stone), and trench backfill volumes.
The Critical Importance of Trench Depth Stratification
Installing a 24-inch storm pipe at a 4-foot invert depth is a fundamentally different operational and financial task than installing that same 24-inch pipe at 13 feet. Depth affects excavation geometry, production and temporary works, but does not alone determine the protective system. OSHA requires cave-in protection except for the specified stable-rock or shallow-excavation exceptions; even an excavation less than 5 feet deep needs protection when a competent person identifies a potential cave-in hazard. Soil classification, loading, water and the selected protection system must be considered.
When estimators fail to stratify utility piping by depth, contractor bids are exposed to severe risk. Our takeoffs segment every foot of pipe into recognized production depth tiers:
Standard Open Cut
Rapid machine cycle times, minimum trench width, minimal shoring requirements depending on soil cohesion classification.
Shored Trenching
Project-specific trench protection, increased trench width to accommodate spreader bars, double-handling of spoil.
Stacked Boxes & Dewatering
Stacked heavy steel boxes, crane or 80k-lb excavator placement, active dewatering pumps, and high-volume stone backfill.
Comprehensive Division 33 Systems Quantified
Our utility estimating team provides complete itemization across all wet and dry site infrastructure disciplines:
1. Water Distribution Utilities (CSI 33 10 00)
Potable water mains, fire protection loops, and irrigation supply lines. Quantified by material (AWWA C900 PVC DR-18/DR-14, Class 52/350 Ductile Iron Pipe), size (2" through 24"), MJ gate valves with valve boxes, tapping sleeves, fire hydrant assemblies with auxiliary gate valves, air release valves, megalug mechanical joint restraints, thrust blocks (CY), pressure testing (LF), and bacteriological chlorination flushing.
2. Sanitary Sewer Utilities (CSI 33 30 00)
Gravity sewer collectors, outfalls, and force mains. Quantified by material (ASTM D3034 SDR-35 / SDR-26 PVC, C900 PVC for shallow cover/crossings), 48", 60", and 72" precast concrete manholes with eccentric cones, flat tops, drop connections, doghouse manholes over live lines, sanitary service laterals with two-way cleanouts, air testing (LF), and mandrel deflection testing.
3. Storm Drainage Networks (CSI 33 40 00)
Conveyance piping (Reinforced Concrete Pipe Class III/IV/V, AASHTO M294 Dual-Wall HDPE, Polypropylene pipe), precast curb inlets (DOT Type A/C/E), grated drop inlets, yard drains, concrete junction boxes, precast headwalls, flared end sections (FES) with toe walls, and dumped riprap aprons (SY and tons) over geotextile filter fabric.
4. Dry Utility Encasement & Conduits (CSI 33 70 00 / 33 80 00)
Primary and secondary electrical power duct banks, telecommunications fiber optic conduits, gas main trenching, concrete encasement encasement (CY), spacer chairs, pull boxes, transformer pads, and light pole foundation trenching.
Trench Geometry & Bedding Formula Calculation
Accurately estimating trench dirt and stone requires calculating pipe displacement and bedding dimensions. Here is the mathematical framework our takeoffs follow:
Trench Dimensioning Formulas:
Trench Width (W) = Outside Pipe Diameter (Bc) + 2 × Working Clearance (typically 12" to 16" per side)Trench Excavation Cut (CY) = [Width (ft) × Average Trench Depth (ft) × Length (ft)] ÷ 27Bedding & Haunching Zone Stone (CY) = [Width (ft) × (Bedding Depth + Pipe Outside Diameter + Cover Above Crown) × Length (ft) ÷ 27] - Pipe Displacement (CY)Bedding Stone (Tons) = Bedding Volume (CY) × Compaction Density (typically 1.35 to 1.45 Tons/CY)
• Gross trench volume = (47/12 × 8.5 × 600) / 27 = 739.81 CY.
• Pipe displacement = π × (23/24)² × 600 / 27 = 64.12 CY.
• Pipe-zone aggregate = [(47/12) × (0.5 + 23/12 + 1) × 600 / 27] − 64.12 = 233.26 CY.
• At an illustrative 1.4 short tons/CY, aggregate = 326.56 short tons before ordering allowances. Confirm the actual material density and installation geometry.
QA/QC Conflict Detection & Invert Auditing
Utility estimating errors lead directly to catastrophic back-charges on bid day. Our senior utility takeoff specialists execute a 4-point verification check before publishing final quantities:
- Vertical Clearance Audit: We cross-reference sanitary sewer and water line profiles at every point of intersection. Municipal standards mandate a minimum of 18 inches vertical separation between water mains and sewer pipes. Any clearance under 18" is flagged for concrete encasement or ductile iron sleeve requirements.
- Invert Slope & Self-Cleansing Velocity Check: We verify the designer's slope across all gravity pipe runs to verify minimum flow velocities (typically 2.0 ft/sec for sanitary sewer and 2.5 ft/sec for storm drainage). Inverts showing zero slope or backward grades are caught and highlighted for RFI clarification.
- Structure Rim-to-Invert Calculation: Every precast structure is checked against finished grading contours to ensure rim elevations match proposed asphalt or curb grade, preventing buried lids or protruding casting hazards.
- Pavement Subgrade vs Native Spoil Segregation: We calculate trench backfill within pavement sections separately from unpaved landscape areas. Pavement trenches require imported crushed aggregate or flowable fill, whereas unpaved runs permit recompacted native spoil.
What Is Included in Division 33 Deliverables
- Itemized Pipe Schedules: Tabulated by utility system (Storm, Sanitary, Water, Conduit), material specification (RCP Class III/IV/V, HDPE Smooth Interior, SDR-35 PVC, C900 PVC, Class 350 DIP), and nominal diameter.
- Depth Stratification Breakdown: Pipe linear footage segregated by 0-6', 6-10', 10-14', and 14'+ depth brackets to align with equipment production rates and OSHA safety shoring costs.
- Precast Structure Schedules: Itemized counts and depths of 48", 60", and 72" sanitary manholes, doghouse manholes, storm curb inlets, drop inlets, junction boxes, and flared end sections (FES).
- Trench Volumes & Materials: Quantities for trench cut cubic yards, asphalt sawcutting linear footage, tons of #57 stone bedding, and compacted backfill volumes.
- Valves, Hydrants & Appurtenances: Resilient wedge gate valves, butterfly valves, fire hydrant assemblies with auxiliary valves, air release valves, thrust blocks, and water services with curb stops.
- Color-Coded Marked-Up Vector Plans: High-resolution vector PDF plans depicting utility runs with distinct colors, structure callout IDs, and stationing for easy field reference and bid reviews.
Underground Utility Takeoff Specifications & Quality Control Matrix
| Takeoff Parameter | Standard Service Specification |
|---|---|
| Measurement Units | Linear Feet (LF by size/class/depth), Each (EA structures/valves/fittings), Tons (TN bedding stone), Bank/Compacted CY (trench spoil/backfill). |
| Drawings Reviewed | Civil Utility Plans (C300), Utility Profiles (C310–C330), Municipal Standard Details (C500), and Geotechnical Boring Logs. |
| Specification Alignment | CSI MasterFormat Division 33 10 00 (Water Utilities), 33 30 00 (Sanitary Sewerage), and 33 40 00 (Storm Drainage). |
| Revisions & Addenda | Addenda tracking: invert slope updates, pipe class revisions, and structure depth delta adjustments with line-item revision callouts. |
| QA/QC Review Protocol | Senior utility estimator audit verifying minimum 18" vertical crossing clearances between water and sewer mains, rim-to-invert depth math, and the stated trench-protection assumptions. |
| Standard Exclusions | Interior plumbing past 5 feet from building envelope, municipal utility meter tap purchase fees, and hazardous pipe abatement (unless requested). |
Five Common Utility Bidding Mistakes We Help You Avoid
Technical Utility Knowledge Base & Contractor Tools
Deepen your utility bid accuracy with our specialized calculations and engineering guides:
Frequently Asked Questions: Underground Utility Takeoffs
How are utility trenches stratified by depth in your takeoffs?
Pipe lengths are grouped into stated bid depth brackets so production and temporary works can be priced. These are estimating categories, not OSHA classifications. Determine protection from site conditions and the applicable requirements, and confirm excavation depth to the trench bottom rather than treating pipe invert depth as excavation depth.
What bedding and backfill materials are calculated for underground pipelines?
We calculate ASTM C33 concrete sand or #57 crushed stone pipe bedding (typically 4 to 6 inches beneath the invert), initial backfill to 12 inches above the pipe crown, and final trench backfill categorized into unpaved native backfill vs pavement section compacted structural fill.
How do you detect utility crossing conflicts between water and sewer mains?
During plan analysis, our estimators review civil profile sheets to verify Ten-State Standards and local municipal codes requiring a minimum of 18 inches of vertical clearance between water mains and sanitary sewer lines. Any vertical or horizontal crossing conflicts are flagged in our takeoff notes for RFI submission prior to bid closing.
What pipe materials and specifications are covered?
We quantify all commercial utility materials including Reinforced Concrete Pipe (RCP Class III/IV/V), High-Density Polyethylene (AASHTO M294 Dual-Wall HDPE), Polypropylene (PP), Polyvinyl Chloride (SDR-35, SDR-26, and AWWA C900/C905 PVC), and Ductile Iron Pipe (AWWA C151 Class 52/350 DIP).
Are utility structure depths and drops calculated individually?
Yes. Every precast manhole, catch basin, curb inlet, and junction box is logged with its unique casting rim elevation, all incoming/outgoing invert elevations, structure height (rim minus lowest invert), and internal drop connection height to ensure exact precast barrel pricing.
Need Your Underground Utilities Quantified Fast?
Upload your civil utility plans (C-300 sheets) and profile drawings. We’ll deliver an itemized takeoff schedule tailored directly to your bid proposal.
Published quantities and scope boundaries
Pipe lengths and structure counts retain their source units. A pipe length is not a trench volume; profiles and installation details are needed for the trench scope.
| Source description | Base quantity | Unit |
|---|---|---|
| 8" DIP Sanitary | 225.69 | LF |
| 8" PVC Fire Main | 1067.4000000000001 | LF |
| Fire Hydrant Assembly | 7 | EA |
Confirm before pricing
Confirm pipe material and outside diameter, plan/profile lengths, invert and trench-bottom depths, bedding envelope, trench protection basis, restoration and testing.
Allowances are separate from net quantities. Missing details, field conditions, temporary works and revisions need explicit treatment in the proposal.
Inspect both excerpts and the drawing preview → · Request a project-specific quote →