Coats’ Soil Profile: Why Piedmont Clay Changes Everything
Harnett County sits in North Carolina’s Piedmont region, where the dominant soil type is the Cecil-Pacolet series—a red-orange clay that defines site preparation and septic system design throughout Coats, Angier, and Dunn. This moderately draining clay originated from weathered granite and gneiss bedrock, creating challenging conditions for both construction equipment and wastewater absorption.
- Excavation Challenges: Piedmont clay hardens like concrete when dry but becomes slick and unstable when wet, requiring experienced operators who know how to work the soil during different seasons.
- Drainage Implications: The clay’s moderate percolation rate (45-90 minutes per inch) means septic drainfields must be properly sized and strategically located to prevent hydraulic overload during Harnett County’s wet springs.
- Compaction Concerns: Heavy equipment can severely compact this clay during site grading, reducing its ability to absorb effluent and potentially causing long-term system failures if not managed correctly during construction.
- Erosion Control: Freshly exposed Piedmont clay erodes rapidly during rain events, requiring proper grading techniques and erosion control measures to protect both the property and neighboring areas.
Common Septic & Site Preparation Issues in Coats
Hydraulic Overload: When Clay Can’t Keep Up
Hydraulic overload occurs when more wastewater enters the drainfield than the surrounding soil can absorb, a particular concern in Harnett County’s clay soils during the wet season (November through March). Symptoms include standing water over the drainfield, slow drains throughout the house, and sewage odors in the yard. In the rural areas around Coats and Dunn, where properties often have larger households or host extended family gatherings, the combination of high water usage and slow-percolating clay can overwhelm undersized systems installed decades ago when county regulations were less stringent.
Poor Site Grading: Water Pooling Where It Shouldn’t
Improper site grading is one of the most common—and most preventable—causes of septic system failure in new construction. When contractors without septic expertise handle site preparation, they often create drainage patterns that direct surface water toward the drainfield area, saturating the soil and preventing proper effluent absorption. This is especially problematic in Harnett County’s rolling terrain, where even slight grade errors can channel runoff from driveways, roofs, and neighboring properties directly into your septic absorption area. B & L Construction & Septic Service designs site grades that protect the drainfield by directing surface water away from the system while maintaining proper driveway and yard drainage.
Tree Root Intrusion: The Silent System Killer
In the established neighborhoods of Angier and Coats, mature hardwoods and pines create beautiful landscapes—but their extensive root systems pose a constant threat to septic laterals and distribution lines. Roots seek out the nutrient-rich environment inside septic pipes, eventually infiltrating through joints and cracks to form dense mats that completely block effluent flow. The Piedmont clay’s tendency to crack during dry summers creates entry points for roots, accelerating this process. Properties with large oaks, sweetgums, or poplars within 50 feet of the drainfield face particularly high risk and often require mechanical root removal every 3-5 years to maintain system function.
Aging Systems in Rural Areas: Time and Technology
Many homes in rural Dunn, Erwin, and Lillington were built in the 1970s and 1980s with septic systems that, while legal at the time, no longer meet current Harnett County standards. These older systems often feature undersized tanks (750 gallons instead of today’s required 1,000-gallon minimum), lack effluent filters (the “kidney” that prevents solids from entering the drainfield), and use outdated clay tile laterals that crack and collapse over time. When these systems finally fail—typically after 30-40 years—complete replacement is usually required, as modern regulations prohibit simple repairs to non-compliant systems.
Complete Septic & Site Preparation Solutions for Harnett County
Our directory connects property owners in Coats and throughout Harnett County with B & L Construction & Septic Service, a contractor uniquely equipped to handle both the construction and septic aspects of property development and maintenance. This integrated approach eliminates the coordination challenges and potential conflicts that arise when hiring separate companies for site work and septic installation.
- New Septic System Installation: Complete design, permitting, and installation services for new homes and replacement systems. B & L handles soil evaluation coordination with the health department, system sizing based on bedroom count and lot characteristics, and excavation using GPS-guided equipment for precise placement. Systems are installed to current Harnett County standards with proper-sized tanks (1,000-1,500 gallons), effluent filters, and appropriately designed drainfields for Piedmont clay absorption rates.
- Land Clearing & Site Grading: Professional clearing of raw land using excavators and dump trucks, with strategic removal of trees and vegetation that could threaten future septic systems while preserving desirable shade trees and natural buffers. Site grading is designed with septic system location in mind, ensuring proper surface water drainage away from the absorption area while creating functional yards and building pads. This is the B & L difference—site preparation that protects your septic investment from day one.
- Septic Tank Pumping & Maintenance: Regular pump-outs for existing systems throughout Coats, Angier, and Dunn, with thorough removal of both liquid effluent and settled sludge layer. Service includes inspection of inlet/outlet baffles, cleaning of effluent filters, and identification of potential problems before they become emergencies. For Harnett County’s clay soils, pumping every 3-4 years is recommended for standard households, with more frequent service for properties with garbage disposals or larger families.
- Driveway Construction: Excavation, grading, and installation of gravel or paved driveways designed to handle the area’s clay soils and drainage challenges. Proper driveway construction includes adequate base material, crown for water runoff, and careful placement to avoid compacting soil over septic lines or drainfields. B & L’s construction expertise ensures driveways that last while protecting underground septic components.
- Septic System Repairs: Expert troubleshooting and repair of failing components, from replacing cracked distribution boxes to repairing damaged laterals. When repairs exceed 50% of system value—triggering Harnett County’s replacement requirement—B & L can handle the complete new installation using the same equipment and crew, minimizing disruption to your property.
- Emergency Response: Available for urgent septic failures, sewage backups, and situations requiring immediate pump-out or repair. The combination of construction equipment and septic expertise means B & L can quickly address complex emergencies that might require excavation, line repair, or temporary system modifications.
Call B & L Construction & Septic Service at (910) 309-0146 or Request Service Online to schedule service or discuss your site preparation and septic needs with the team that handles it all.
