Sea Level Rise, Septic Systems, and Resilience and Retreat

Rising groundwater causes septic system failures (from “Septic Systems Vulnerable to Sea Level Rise”)

SNAPSHOT: A new law in Virginia requires the Department of Health to include, “Consideration of the impacts of climate change on proposed treatment works,” in its septic regulations. This novel provision could cause major changes for development in low-lying coastal areas/rural communities and could become part of a retreat and relocation strategy for at-risk residences. In coastal Virginia, as all along the Atlantic Coast, sea level rise is causing septic system failures. Rising sea levels elevate the groundwater under these systems, flooding them out. As well, more intense rainfall is stressing systems and causing periodic failure. With so many rural areas using septic, this is a widespread problem, and one that Virginia’s Department of Health will tackle this fall as it rewrites septic system regulations to comply with the new law.

BACKSTORY: Septic systems provide waste treatment for many residences in coastal areas, especially in rural areas where connections to sewage plants are impractical. In recent years, rising sea levels have started to compromise septic systems or caused them to fail completely. This is due to elevated groundwater levels, driven by sea level rise, that brings water into septic drainfields, as shown in the illustrations above. As well, more intense rainfall has caused system failures where the systems were improperly installed or where soil conditions cause rainfall to flood drainage fields.

Today septic permits are issued without regard to future conditions, creating headaches for rural communities facing sea level rise and more intense rainfall events. In 2021, State Senator Ghazala F. Hashmi of suburban Richmond’s District 10 introduced SB 1396 to include climate change in septic permitting. The new law resulted in the Virginia Department of Health deciding on a comprehensive re-write all of the regulations governing onsite septic, which was last done in 2000.

These conditions are serious as pollutants and bacteria leach into surrounding waters, compromising shellfish aquaculture and water quality. The Virginia Institute of Marine Science is studying some of these issues. In addition. a condition of occupancy is the ability to dispose of waste - if the septic systems fail, condemnation of the property follows. Solutions are not cheap or easy. You can pump out the septic system and dispose of the waste at nearby treatment plants. You can also build new advanced onsite septic systems (AOSS) such as the ones pictured below in Mathews County, Virginia, that are built above the land surface and can avoid groundwater intrusion…for a while anyway.

But those system are expensive, more expensive than most working class people can afford. The 2021 legislation created a fund, “ to provide grants and loans to property owners with income at or below 200 percent of the federal poverty guidelines to repair failing onsite sewage systems or install onsite sewage systems on properties that lack adequate sewage disposal.” But there is not enough money in the fund to take care of all of those who are facing the problem.

So as we develop new regulations to prevent expanding this problem in the future, we need to find ways to address the needs of people who are being left stranded in rural areas. And, for some of our coastal areas under greatest threat of sea level rise, onsite septic policy decisions become resilience and retreat decisions.

READ MORE:

Septic Issues in Virginia - “Septic system failures expected to increase in coastal Virginia”

Septic Issues in North Carolina - “Sea Level Rise Puts Septic, Sewers At Risk”

Septic Issues in Georgia - “Septic Tanks Threaten Water Quality on Georgia’s Coast as Sea Levels Rise”

Septic Issues in Miami - “Septic Systems Vulnerable to Sea Level Rise”