TxDOT Item 506 Temporary Erosion, Sedimentation, and Environmental Controls: Bid Code Spec, Pricing and Post-Installation Requirements
Item 506, Temporary Erosion, Sedimentation, and Environmental Controls, covers rock filter dams, sediment control fence, biodegradable erosion logs, construction exits, and other BMPs, each with its own install and remove pay item. This covers the 15 bid codes that show up most often across recent TxDOT lettings, what separates one from the next, what's carried inside the price either way, and the one obligation on this item that can shut down your entire project.
TxDOT Item 506 Bid Code Variants: What Determines Pricing
Item 506 isn't one product line, it's a bundle of unrelated devices that all happen to serve erosion and sediment control. The spec lists what's included: "rock filter dams, temporary pipe slope drains, temporary paved flumes, construction exits, earthwork for erosion control, pipe, construction perimeter fence, sandbags, temporary sediment control fence, biodegradable erosion control logs, vertical tracking, temporary or permanent seeding, and other measures."
Three things determine what you're actually pricing:
- Which device. Rock filter dams, sediment control fence, biodegradable erosion logs, and construction exits are the four device families in this set of 15 codes. Each has its own materials section, its own construction method, and its own price level. A rock filter dam install averages $45 in this data. A sediment fence install averages $4. Same Item number, nothing else in common.
- Install or remove. Every device family here has a separate install code and a separate remove code, and remove is consistently the smaller number, not a small discount, a fraction. Across all four families in this data, removal prices at 25 to 33 percent of installation. More on that below, it's the single clearest pattern in the pricing.
- Size, on the biodegradable logs specifically. The logs come in diameters, 8, 12, and 18 inch, "as shown on the plans or as directed." Worth knowing 8 and 12 inch price the same in this data, $6 either way, and the jump only shows up at 18 inch, $9. Don't assume a straight line from diameter to price.
TxDOT Item 506 Pricing: Key Takeaways
- Removal prices at roughly a third of installation, consistently. Confirmed across rock filter dams, construction exits, sediment fence, and biodegradable logs. Don't price a removal item off your install rate without adjusting.
- The real obligation on this item isn't a device, it's monitoring. Daily inspection, 7-calendar-day correction windows, and a stop-work consequence that hits the whole project, not just the erosion control scope.
- Most Item 506 work is subsidiary or bundled, PSL erosion control, litter removal, minor adjustments, and finish grading are folded into other items or not paid at all.
- A CRPE has to be named in writing at the preconstruction conference, with a specific set of daily responsibilities. This isn't optional paperwork, it's a named-person compliance role.
Cost Factors for TxDOT Item 506 Temporary Erosion, Sedimentation, and Environmental Controls
Cost Factors That Vary by Bid Code
Work through these one code at a time. They're what makes 506-7002 a different number than 506-7011.
- Which device you're pricing. Rock filter dams need aggregate sized by type, 3 to 6 inch for Types 1, 2, and 4, 4 to 8 inch for Type 3, plus wire mesh specs on Types 2 through 4. Sediment control fence needs a specific fabric (DMS-6230) and net reinforcement. Biodegradable logs need a biodegradable or recyclable core and a matched containment mesh, temporary installs get recyclable mesh, permanent ones get biodegradable or photodegradable. Different material list, different price, every time.
- Install versus remove. The clearest driver on this item. Installation carries the material cost, the construction labor, and getting it right the first time. Removal is disposal and site cleanup. The ratio holds close to 30 percent across every device family with both codes present in this data.
- Rock filter dam type and height. Types 1 and 2 need at least 18 inches of height, Type 3 needs at least 36. Type 4 is a different construction method entirely, sack gabions, laced and filled with stone rather than built up from loose aggregate. That's a labor difference, not just a materials one.
- Construction exit duration. Long-term exits need a foundation course and a minimum width, 14 feet one-way, 20 feet two-way. Short-term exits can go down with just crushed aggregate, plywood, or wafer board. Long-term is the bigger build.
- Quantity risk depends on the device's measurement basis, not one rule for the whole item. Rock filter dams can be measured by the foot or the cubic yard, your choice affects how a quantity dispute gets resolved. Everything else on this list is measured by the foot. Know which basis your specific code uses before you price it.
Cost Factors That Apply to Every TxDOT Item 506 Bid Code
These don't separate one device from another. They sit under all of them.
- A named Contractor Responsible Person Environmental, not a role, a person.
"Provide and designate in writing at the preconstruction conference a CRPE and alternate CRPE who have overall responsibility for managing environmental compliance."
That person implements SWP3 practices, oversees monitoring, and has to be reachable by phone 24 hours a day for environmental emergencies. This is a staffing cost that sits on top of whatever device you're pricing, and it doesn't scale down for a small erosion control scope. - Daily monitoring, every day there's a BMP in place. Not periodic, not weekly, daily, for as long as any control measure is in the ground or soil disturbing activity is happening. Time suspensions and non-work days are the only exceptions, and only if there's been no rain.
- Stabilization has a 14-day clock.
"Initiate stabilization for disturbed areas no more than 14 days after the construction activities in that portion of the site have temporarily or permanently ceased."
- Materials removed are considered consumed by the project, meaning you don't get to reclaim and resell aggregate or fabric that's already been installed and removed, with one exception, stockpiled material stays yours until new installations or replacements are no longer needed.
TxDOT Item 506 Payment Terms: Subsidiary Work vs. Separately Paid Items
This is where a bid built on the device prices alone comes up short. The spec opens Section 6 with a bundle of things that never get their own line item.
Subsidiary, meaning it's already inside your device unit price, before a single device gets mentioned:
"The following will not be paid for directly, but will be subsidiary to pertinent Items: erosion control measures for Contractor project-specific locations (PSLs) inside and outside the right of way... removal of litter, unless a separate pay item is shown on the plans; repair to devices and features damaged by Contractor operations; added measures and maintenance needed due to negligence, carelessness, lack of maintenance, and failure to install permanent controls; removal and reinstallation of devices and features needed for the convenience of the Contractor; finish grading and dressing upon removal of the device; and minor adjustments."
That's seven separate categories of work folded into your device price before you even get to the per-device payment clauses. PSL erosion control specifically is easy to miss, it covers your own haul roads, field offices, and material sources, not just the project right of way.
Also subsidiary within specific devices: removal of temporary pipe slope drains is subsidiary to the installation item, not paid separately. Vertical tracking is never paid or measured directly, always subsidiary. Riprap or concrete used as an energy dissipater gets paid under Item 432 instead, not this one.
Where maintenance work actually gets paid. Routine correction work is subsidiary, but cleaning and restoring control measures after they've done their job, removing accumulated sediment, re-grading, dewatering, runs through a Contractor Force Account item on invoice, not a fixed unit price. That's a real payment path, worth knowing it exists rather than assuming everything past initial install is free labor.
Replacement work is a real, paid event, when the Engineer directs it. Rock filter dams replaced on direction get paid at both the Remove and the Install unit price. Same structure for sediment fence and construction exits. Contractor-driven replacement for your own convenience doesn't get this treatment, that's the subsidiary bucket above.
TxDOT Item 506 Post-Installation Requirements: Monitoring and the Stop-Work Consequence
Item 666's post-installation risk is a measured number, retroreflectivity, checked once, restripe if it fails. Item 506's is different in kind, an ongoing monitoring obligation that runs for the entire time a BMP sits in the ground, with a consequence that isn't limited to the erosion control scope.
The Department inspects, then hands it back to you on a clock.
"Make corrections as soon as possible before the next anticipated rain event or within 7 calendar days after being able to enter the worksite for each control measure. The only acceptable reason for not accomplishing the corrections within the timeframe specified is when site conditions are considered 'too wet to work.'"
Miss that window and it isn't just the erosion control work that stops.
"When corrections are not made within the established timeframe, all work will cease on the project and time charges will continue while the control measures are brought into compliance."
Read that again: all work, project-wide, while time charges keep running. This is not a per-device restripe, it's a full project stop-work with a running clock against you.
Commencing work doesn't clear the liability either.
"Commencing work does not release the Contractor of the liability for noncompliance with the SWP3, the plans, or TPDES CGP TXR150000."
Final acceptance has its own threshold, and it's a vegetation number, not a device count. Projects need 70 percent vegetative cover density relative to existing adjacent undisturbed area before acceptance, with an arid-area exception. That's a biological outcome you're accepting liability for, not just a construction task.
Documentation runs the whole time, not just at closeout. Daily monitoring reports, control measure condition, inspection date, corrective actions and who's responsible for them, and when they were completed. Records available within 24 hours of a request. A Construction Stage Gate Checklist gets completed periodically by the CRPE together with an Engineer's representative.
Pricing Considerations for Monitoring and Compliance
- The CRPE role itself is a cost, whether it's a dedicated hire or a existing staff member's added responsibility. Daily monitoring for the project's full duration, not just while devices are being installed.
- A stop-work contingency, sized to what a project-wide shutdown costs per day, not what a single device restripe costs. This is a different order of magnitude than Item 666's exposure.
- Force account rates for maintenance work, since cleaning and restoring control measures after a rain event runs through invoiced force account, not your bid unit price, worth having a rate ready rather than negotiating it mid-project.
- Documentation labor, someone has to produce and file daily reports for as long as any BMP is active, which on a long project is most of the schedule.
TxDOT Item 506 Bid Item Pricing Data
Average unit price across TxDOT lettings over the last 24 months. Each code links to its full pricing page, where you can see the spread by competitor, by district, and by quantity band.
Pricing Analysis: Key Cost Comparisons Across TxDOT Item 506
The useful comparisons are between codes that are identical except for one thing. Whatever gap shows up is what the market charges for that one difference.
Removal prices at roughly a third of installation, and it holds across every device family with both codes present.
Four independent device families, four ratios within a 10-point band of each other. That's not coincidence, that's the market pricing removal labor and disposal consistently relative to a full install, regardless of what the device actually is.
Biodegradable log pricing doesn't scale smoothly with diameter. 8 inch and 12 inch install at the same $6. 18 inch jumps to $9, a 50 percent step, not a proportional one. If you're pricing an 18 inch log off your 12 inch rate, you're underpriced.
Executing TxDOT Item 506: Avoiding Rework and Ensuring Payment
For whoever's running the job. Same spec, stated as things to do.
Rework Triggers Under TxDOT Item 506
- Corrections not completed within 7 calendar days of site access, or before the next rain event, triggers project-wide work stoppage with time charges still running
- Damage to devices caused by Contractor operations, repaired at your cost, not paid separately
- Added measures or maintenance needed due to negligence, carelessness, or failure to install permanent controls, not paid for directly
- Discharges or spills that violate Edwards Aquifer Rules, water quality standards, or federal and state law
- Vegetative cover short of the 70 percent density threshold at the point you're expecting acceptance
Field Compliance Requirements for TxDOT Item 506
- CRPE and alternate CRPE designated in writing at the preconstruction conference, both attending
- CRPE reachable by phone 24 hours a day for environmental emergencies
- Daily site monitoring for as long as any BMP is in place or soil disturbing activity is underway, rain-event exception on non-work days only
- Spill kit kept onsite, chemical and hydrocarbon spills addressed immediately
- Training completed under Section 7.7.4.4 before any applicable employee works on the project, documented and signed by the CRPE
Pay Application Requirements for TxDOT Item 506
- Daily monitoring reports on file, covering control measure condition, inspection date, corrective actions, who's responsible, and completion date
- Records available within 24 hours of a request, not "eventually," a hard turnaround
- Training records maintained, employee name, course name, and completion date, signed by the CRPE
- Construction Stage Gate Checklist completed periodically, jointly by the CRPE and an Engineer's representative
- Know which payment path applies: routine correction is subsidiary, but cleaning and restoring control measures after they've functioned runs through Force Account on invoice, a different documentation trail entirely
Built for people pricing and executing TxDOT erosion control work
Frequently asked questions about TxDOT Item 506
What is TxDOT Item 506, Temporary Erosion, Sedimentation, and Environmental Controls?
It's the TxDOT spec covering the Best Management Practices used to control erosion and sedimentation during construction, rock filter dams, sediment control fence, biodegradable erosion logs, construction exits, and several other devices, along with the SWP3 monitoring and compliance obligations that apply to all of them.
Why does removal price so much lower than installation on this item?
Removal is disposal and site cleanup, without the material cost or the construction labor of getting the device built correctly the first time. Across the device families with both codes present in this data, removal consistently prices at 25 to 33 percent of installation.
What happens if I miss a correction deadline on an erosion control device?
The spec gives you 7 calendar days from site access, or before the next anticipated rain event, whichever is sooner. Miss it, and all work on the project ceases, not just the erosion control scope, with time charges continuing until compliance is restored.
Who is the CRPE, and is it a real staffing requirement?
The Contractor Responsible Person Environmental, a specific individual designated in writing at the preconstruction conference, with overall responsibility for environmental compliance, daily monitoring, and 24-hour emergency availability. It's a named role with real obligations, not a title assigned on paper.
Is surface cleanup or maintenance work on erosion control devices paid separately?
Routine correction is subsidiary, inside your device price. Cleaning and restoring control measures after they've accumulated sediment, meaning the maintenance work itself, is paid through a Contractor Force Account item from invoice, a different payment path than your bid unit price.
Do biodegradable erosion control log prices scale with diameter?
Not smoothly. In this data, 8 inch and 12 inch install at the same price, and the jump only shows up at 18 inch. Don't assume a linear relationship between size and cost.
What vegetative cover is required before a project can be accepted?
70 percent density relative to existing adjacent undisturbed areas, with an exception for arid areas as defined in the TPDES Construction General Permit. The Engineer may accept work before that threshold is reached at their discretion.
Is materials salvage possible on this item?
Generally no. Materials removed are considered consumed by the project. The one exception is stockpiled material, which you retain ownership of until new installations or replacements are no longer needed.
Is this pricing data free to use?
Yes. Every bid item pricing page linked above is free, no account needed.