Industrial Wastewater Requirements for Concrete Batch Plants Yanisa Angulo and Ilia Balcom Industrial Wastewater Program DEP Southwest District
SWD IW Jurisdiction Citrus, Desoto, Hardee, Hernando, Hillsborough, Manatee, Pasco, Pinellas, Polk, Sarasota, Sumter, and west Marion County
Why do we care about Concrete Batch Plants (CBPs)? Primary concern is contaminated storm water and interior truck mixer drum wash- out water.
Why do we care about Storm Water? • In general, storm water can contain high levels of contaminants. *sediments, nutrients, heavy metals, pathogens, toxins, oxygen demand • For CBP pollutants of concern are: pH, suspended solids (TSS), petroleum hydrocarbons (TRPH) and specific conductance.
Two “Types” of Wastewater (Contaminated Storm Water & Process Wastewater) • Type I Wastewater Includes: *Contact storm water (Exposure areas) *Runoff from aggregate piles (process) *Washdown water not including interior mixer drum washout (process)
Type I Wastewater • Washdown water *Water sprayed for dust control (process) *Does not include equipment washing or truck undercarriage washing (process) *Includes washing of exterior of mixer trucks and mixer truck chutes, or other washing operations (slump racks, etc.)
Type II Wastewater • Wastewater generated from the washout of the interior of a concrete truck mixer drum and any water that comes into contact with this wastewater. • Excludes reclaimed Type II wastewater used to spray aggregate piles.
Permit CoverageRule 62-621.300(3)(a), F.A.C. • Permit coverage is under Chapter 62-621.300(3)(a), F.A.C., effective May 1997. • http://www.dep.state.fl.us/water/wastewater/iw/docs/62-621.300_3a.pdf • Need to meet the permit criteria. Coverage is for 5 years. • An application of renewal of coverage is required to be submitted 180 days prior expiration of the current permit coverage.
Two Types of CBP Systems • Existing: In operation before May 1996 Includes Unpermitted Existing Systems • Unpermitted existing systems were covered under the voluntary consent order that required to obtain permit coverage after construction of system was completed. • New: In operation after May 1996 • Currently there are 137 permitted CBPs in the SWD
The difference in requirements between New and Existing CBP • New - Basically the storm water treatment requirements for wet detention/retention systems are more stringent. • New - Must account for non contact storm water. Non-contact storm water includes those areas on the site that do not have exposure to industrial pollutants (roof runoff, parking areas, etc).
Requirements of a Permit Application • Notice of Intent to Use Generic Permit for Discharges from Concrete Batch Plants, DEP Form 62-621.300(3)(b) • $500 Application Fee • Engineering Report signed and sealed by a Professional Engineer registered in Florida • http://www.dep.state.fl.us/water/wastewater/forms.htm
What Does CBP GP Require? • Retain Type II wastewater and runoff from Type II area up to 25-year/24-hour storm. • Control/Treat Type I Wastewater and Storm water with Wet Detention or Dry Retention Ponds. • Implementation of Wastewater and Storm water Management Practices (WSMP).
Engineering Report Includes • Description of Type I, Type II, and non-contact stormwater management systems and how they operate. • Description of how solids are handled, used or disposed of. • Description of close-loop vehicle/equipment wash facility, if applicable. • Site plan indicating existing and proposed wastewater and stormwater management systems, drainage basins, direction of flow, and discharge points, receiving waters, pervious and impervious areas.
Engineering Report Includes (Cont.) • Design Criteria: • Calculation of designed daily Type I and Type II flow, • stormwater runoff calculations, • Design stormwater an sources of data • Stage/storage calculations • Percolation rate determination
Type II System Design Requirements – (New and Existing Facilities) • Impermeable containment • Contain produced Type II wastewater plus direct rainfall into and storm water runoff from Type II area, resulting from 25-yr, 24-hr storm events • No direct discharge from the Type II system to groundwater or surface waters • Runoff from ribboning area should be directed to the type II System • Overflow from the Type II system shall discharge to a Type I system or an emergency holding pond only as a result of rainfall in excess of the 25-yr, 24-hr storm event.
Type I System Design Requirements – (Existing Facilities) • Wet detention • Sediment trap(s), mostly constructed of concrete • Offline wet detention to treat first ½ inch of runoff from Type I area plus produced Type I wastewater • Drawdown (control) device: orifice, v- or square-notch weir • Overflow device: standpipe or weir • One-half of the treatment volume is recovered within the first 48-60 hours following a rain event
Type I System Design Requirements (Cont.) • Dry Retention • The retention system must retain produced Type I wastewater plus one of the following: • runoff from 10-year, 24-hr storm • runoff from the first 1-inch of rainfall • the first ½ inch of runoff • Demonstrate recovery of system storage capacity within 72 hrs following any runoff producing event through percolation to ground water and evaporation
Type I System Design Requirements (New Facilities) • Wet detention-Off line wet detention • Sediment trap(s) • Offline wet detention to treat first ½ inch of runoff from Type I area • One-half of the treatment volume is recovered within the first 48-60 hours following a rain event • Drawdown(control)device: orifice, v-or square-notch weir • Overflow device: standpipe or weir
Type I System Design Requirements– New Facilities (Cont.) • Final Wet Detention • One-half of the treatment volume is recovered within the first 48-60 hours following a rain event • Detain and treat the discharge from the off-line system and runoff from the type I area and non-contact storm water area of the site • Drawdown (control) device: orifice, v-or square-notch weir • Overflow device: standpipe of weir
Type I System Design Requirements – New Facilities (Cont.) • Dry Retention • The retention system must retain run off from the Type I area of the site, including all produced Type I wastewater and runoff from non-contact area resulting from 10-year, 24-hr storm • Demonstrate recovery through percolation to ground water and evaporation
Type I System Design Review – New Facilities (Cont.) • Pre vs. Post-development • Post-development rate of discharge of storm water runoff must not exceed pre-development rate of discharge for • A 25-yr, 24-hr storm event or • A 100-yr, 24-hr storm event for a closed drainage basin
Wastewater and Storm Water Management Plan (WSMP) • WSMP identifies storm water pollution prevention and Best Management Practices (BMPs). • Pollution prevention includes things like clean up of petroleum/hydraulic fluid spills and other spills. Use of low volume wash waters for wash down and reuse (there have been some innovative designs).
Wastewater and Storm Water Management Plan (WSMP) – Cont. • Pollution prevention is required to prevent the discharge of contaminants from storm water related events. • BMPs include on-site procedures and practices implemented to ensure long term operation and maintenance for storm water and Type II systems.
Wastewater and Storm Water Management Plan (WSMP) – Cont. • BMPs include practices for beneficial reuse of Type I and Type II solids and wastewater. • BMPs include proper procedures for solids disposal. • The WSMP specifies how often Type I and Type II systems must be inspected, and inspections shall be documented on the WSMP. • BMPs should address ribboning practices, including rain events
Sweeping Requirement • Facilities shall prevent or minimize the discharge of spilled cement, aggregate (including sand or gravel), kiln dust, fly ash, settled dust and other significant materials in stormwater from paved portions of the site that are exposed to stormwater. Measures used to minimize the presence of these materials may include regular sweeping, or other equivalent measures.The plan element shall indicate the frequency of sweeping or other measures. The frequency shall be determined based upon consideration of the amount of industrial activity occurring in the area and frequency of precipitation, but shall not be less than once per week when cement, aggregate, kiln dust or fly ash are being handled or otherwise processed in the area.
Compliance Evaluation Inspections • Inspections conducted on an annual basis. • Inspectors evaluate compliance with permit requirements, including record keeping and operation and maintenance. • DEP is required to conduct unannounced inspections. • Inspections can also be initiated by a complaint.
Compliance issues for Existing/New Permitted Systems • General • Failure to apply for renewal of permit coverage as required (180 days prior expiration). • Failure to submit abandonment plant prior to closure of a facility and inactivation of a permit • Failure to construct the treatment systems in accordance with the permit requirements or as designed.
Compliance issues for Existing/New Permitted Systems (cont.) • Record Keeping Issues: • Failure to have a copy of the permit on-site. • Failure to have a copy of the “as-builts” (engineering drawings) on-site. • Failure to develop a Wastewater and Storm Water Management Plan (WSMP) as required. Or, if developed, WSMP was not on-site, or not updated. • Failure to implement WSMP.
Compliance issues for Existing/New Permitted Systems (cont.) • Recordkeeping Issues (Cont.) • Failure to conduct inspections required by the WSMP. If conducted, failure to properly document them (complete checklists). • Lack of training of on-site personnel regarding WSMPs and CBP permit requirements. • Failure to submit completion of construction and record drawing notification forms.
Compliance issues for Existing/New Permitted Systems (cont.) • Type II system Issues: • Improper handling of truck wash water and other wash waters. • Improper dewatering of Type II solids. • Spills as a result of cleaning sediment pits. • Spills as a result of cleaning Type II systems. • Unauthorized overflows (discharges) from the Type II system caused by lack of maintenance. • Co-mingling of Type II and Type I wastewater
Compliance issues for Existing/New Permitted Systems (cont.) • Type I System Issues: • Failure to clean sediment pits. • Failure to clean out solids from storm water ponds. • Clogging of outlet structures in the storm water ponds. • Failure to address erosion control in storm water ponds. • Excessive vegetation that affects the pond’s performance and hinders inspection of berms. • Unpermitted discharges due to loss of capacity or breached berms.
Compliance issues for Existing/New Permitted Systems (cont.) • Although a CBP operating under the Generic Permit is not required to sample, the facility must meet applicable ground and surface water quality standards. If for some reason there isn’t reasonable assurance that the facility can meet standards, samples may be required to ensure that BMPs, WSMPs, and systems were adequately designed. Main pollutants of concern include: pH, turbidity, TSS (suspended solids), TRPH (petroleum hydrocarbons), and specific conductance.
Potential Penalties associated with violations of the Generic Permit • The Department has the statutory authority to impose fines for up to $10,000 per day. • Under the Environmental Litigation Reform Act, the following amounts apply to specific violations: • Unpermitted Discharge: $2,000 if no violations of water quality standards, $5,000 if violations of water quality standards. • Failure to install, maintain or operate a pollution control device: $4,000. • Failure to submit required notification: $1,000. • Failure to prepare, maintain, submit or use required reports or other documentation $500 . • These amounts could be higher if the violation occurs more than one time (multi-day) or if there is a history of non-compliance.