Recent Florida legislation requires all wastewater utilities to eliminate non-beneficial surface water discharge by 2032—which is easier said than done in a state surrounded by water, covered in sensitive lands, and with a notoriously wet rainy season. Despite Florida being a leader in public access reuse (PAR), surface water discharge is not an uncommon effluent management strategy when PAR has been exhausted.
When effluent production exceeds the reuse water demand and storage capacity, excess flow is typically sent to a permitted surface water body. These excessive flows are common during the rainy season when irrigation demands are stifled or in cities where reuse water systems are limited to non-existent. Many mature reuse systems have a difficult time achieving more than 50 percent reuse due to the supply and demand imbalances between wet weather and dry weather periods in Florida. For water utilities that rely on surface water discharge as a means of effluent disposal, compliance with Senate Bill 64 (SB 64) presents significant obstacles for years to come.
SB 64 Requirements
SB 64 requires utilities to eliminate non-beneficial surface water discharge or demonstrate alternative means of compliance, such as 90-percent reuse of a facility’s annual average daily flow rate (AADF). By now, all utilities producing reuse water and/or discharging to surface water have submitted their written compliance plan to the Florida Department of Environmental Protection (FDEP). As utilities patiently wait for FDEP to review their written plan, budgeting and capital planning for many utilities is already underway, as these often long term and costly projects are required for completion by January 1, 2032.
An increase in alternative effluent management projects can be expected across the state. Reuse system improvement and expansion projects may be the first logical choice for utilities with existing systems that can cost effectively and reasonably be expanded upon to reach the 90-percent reuse requirement. Utilities with little to no reuse water system infrastructure are faced with larger hurdles to overcome, as retrofitting existing infrastructure with reuse water is not a quick or cheap endeavor. For other utilities, expansion of the reuse system may not be cost effective due to corridor congestion or other constructability concerns.
Many utilities are looking to Florida’s non-potable aquifers as a “catch-all” alternative effluent management solution. Rapid Infiltration Basins (RIBs) and spray fields are used in locations where well-draining soils readily accept effluent. In other places where the surficial aquifer is saturated or less permeable, aquifer recharge (AR) and aquifer storage and recovery (ASR) are proven technologies where reuse is pumped into a confined, non-potable aquifer through a permitted Underground Injection Control (UIC) well. AR and ASR wells enable wet season storage and dry season recovery for distribution as reuse water or potentially potable water reuse.
AR can also provide benefits through restoration of depleted aquifer levels and mitigating salt water intrusion. Water management districts may allow recovery of a portion of the water recharged, often up to 90 percent, through separate recovery wells that can then be used to supplement the PAR during dry season or potable water reuse. ASR wells store and recover reuse water from the same well, operating within the freshwater bubble created through storage.
These UIC options are typically viewed as beneficial reuse projects, whereas the other UIC option of a Deep Injection Well (DIW) is considered effluent disposal without an associated benefit to local water resources. Many utilities in Florida are already using DIWs to back up their reuse systems when demands are low, which eliminates the need for permitted water discharges.
Challenges to Consider
There are many challenges associated with AR and ASR projects, including permitting, stored water chemistry, native water chemistry, confinement layers, mobilization of naturally occurring arsenic, and more. These elements are examined during the site review and/or exploratory test well phase to determine if the site and its underlying geology is suitable for full-scale implementation. The site evaluation, exploratory test well(s) and full-scale implementation programs come at significant costs to utilities. These wells are highly regulated through Florida’s UIC program, which has rules promulgated based on the federal UIC program implemented through the Safe Drinking Water Act (SDWA).
With the recently passed H.R. 3684 – Infrastructure Investment and Jobs Act (IIJA), also widely known as the “Infrastructure Bill,” funding from fiscal year 2022 through fiscal year 2026 is anticipated to be available to assist Florida utilities in achieving SB 64 compliance, particularly through AR and ASR projects. Section 50205 (Clean Water Infrastructure Resiliency & Sustainability Program) and Section 50222 (Enhanced Aquifer Use & Recharge) combined have over $150 million available in funding for AR and ASR projects. If utilities are interested in seeking aquifer recovery for potable water reuse, Section 50203 (Pilot Program for Alternative Water Source Projects) has an additional $125 million available in funding.
With a short five-year span, preparing and planning for these projects will be essential in successfully obtaining federal funding. Utilities should begin planning and aligning themselves with funding opportunities now. Preparation may be in the form of completing environmental reviews, preliminary design reports or facility plans prior to the grant application. Many utilities will be seeking these funds, but as they say, the early bird gets the worm (or at least is more likely to). Depending upon a utility’s expected storage requirements, increasing the number of stakeholders through neighboring utilities may ease financial burdens while improving funding approval likelihood.