The Handbook has changed the regulations to reduce the maximum allowable phosphorous load from 0.41 to 0.26 lbs/ac/yr.  This is against the Code 9VAC25-870-63 and 9VAC25-875-580 which are explicit and state as follows: “1.  New development. The total phosphorus load of new development projects shall not exceed 0.41 pounds per acre per year, as calculated pursuant to 9VAC25-870-65.”  The new VRRM spreadsheet significantly hurts developments with lawns (single family subdivisions, churches, parks, schools, etc) by almost 80% in additional load requirements.  This is a new burden that increases costs for a significant portion of Virginians.

This is a very significant and expensive change and I’m having difficulty understanding if there is any science behind this change.  Is this just a decision made by an individual at DEQ?   What are the guidelines for changing these pollutant loads, shouldn’t it have to go through some vetting process?   I just read very recently that the Chesapeake Bay “clean up” plan was well ahead of its target measurements and yet as a developer, I am getting hammered with additional costs that will simply be added to the cost of the lots and homes I’m building.  

Virginian developers are being hit with all these incidental costs that keep driving up housing costs, putting housing out of the reach of many “would be” homeowners.

I asked my engineer to calculate the change in my pollutant load cost on a development that I am currently in the middle of.   Under the current rules, I had to pay $20,000 for the off-set costs, but under the new guidelines, it will be 5 or 6 times that cost!  $100,000- to $120,000!  This seems to really penalize the more rural developments with yards and single-family homes…this is not a reasonable adjustment and should NOT go into effect. Please leave the pollutant load unchanged at the .41 lbs./ac/yr., that is expensive enough, as is.

I have been developing since 2000 and brought over 800 lots and homes to the market during that time. The 2014 changes were particularly painful and expensive and these new changes are not going to help our home shortages and higher prices.  Does Governor Youngkin know about these more stringent regulations and additional burdens on housing.  I heard he was all about reducing and streamlining the regs governing housing.  I think he needs to know.

In general, the VRRM v4.1 version appears to favor projects primarily composed of impervious surfaces over those mainly consisting of managed turf. Projects such as schools, athletic fields, parks, single-family residential subdivisions with lots larger than 0.5 acres, churches, and industrial parks featuring large graded grass pads for future development will experience significant impacts under this version of the VRRM. Upon re-evaluating the pollutant removal for three residential single family subdivisions previously approved with VRRM v3 between 2020 and 2023 using VRRM 4.1, we observed a notable increase in pollutant removal requirements, surpassing 50% in most cases and reaching up to 130% in one instance. Clearly, this version does not offer a one-size-fits-all solution and will impose substantial burdens on projects predominantly covered by managed turf.

Additionally, it's acknowledged by DEQ that a regulation change is necessary for the enforceability of VRRM 4.1. Consequently, these regulations should be amended before the guidance is adopted, as the current guidance deviates from existing regulations.

While the formulas used to support the Runoff Reduction Method are complex, the Virginia RRM has only 2 variables, the land cover of a property (in acres) and its associated Hydrologic Soil Group (HSG). With accurate data, this formula produces the Total Phosphorus and Nitrogen loads with an accuracy of 1/100 of a pound.

Calculating the land cover is a straightforward process for any Civil Engineer or Surveyor. Likewise, determining the HSG is a simple task for any Soil Scientist, Onsite Soil Evaluator or Environmental Health Specialist. However, DEQ has mandated that the HSG can only be determined using NRCS Soil Maps. These maps, especially those relying on Complexes and "Urban" Soil Series, are marked with warnings that they are not to be relied on for providing numerical values for onsite soils.

This mandate means that every use of the VRRM has a 1 in 4 chance of producing an accurate result. I believe the hundreds of homeowners who are being forced to spend thousands of dollars for the preparation and review of these plans would appreciate a better product and more serious approach.

My work has required me to review the BMP plans for many single-family homes in Northern Virginia. I have noted that, regardless of the accuracy, most of the homes are calculated to produce a potential phosphorus load of approximately 1 1/2 to 2 ounces a year. For this, the homeowners are forced to spend anywhere from $30K to more than $100K to have BMPs installed on their properties.

According to the American Society of Agricultural Engineers a single head of cattle, or horse, produce an actual phosphorus load of approximately 1 1/2 to 2 ounces a day in its manure. In other words, a single horse or cow produces as much phosphorus in a year as over 350 single family homes.  And while homes now have severe restrictions on where they can be in relation to the waters of the Chesapeake Bay, bovine and equine livestock have none. The exemptions in the SWM regulations make their pollutants invisible to the eyes of those we have put in charge of enforcing our Environmental Regulations. It is time for the General Assembly to stop the enforcement of Phase II of the CBay W.I.P. until it can be rewritten to better succeed in protecting the Bay.

March 27, 2024

Mr. Mike Rolband

Director of the Virginia Department of Environmental Quality

RE:  VRRM Version 4.1

NOTE: As a member of the SAG, I originally submitted these comments on August 17, 2023 as part of the informal comment period. However, I later became aware that the comments were never registered or considered by DEQ. Therefore, I am resubmitting, as I believe these comments are still relevant for VRRM Version 4.1.

I appreciate the opportunity to comment on VRRM Version 4.1, as well as supporting documents that have been provided.  It is an important step for DEQ and the Commonwealth to provide this updated analysis in addition to the extensive work being done on the manuals and regulations.  I have provided several comments below, accompanied by suggestions for addressing each comment category.

The VRRM is a Compliance Tool

As a member of the team that developed the original VRRM, the good work conducted for this update reminded me of conversations (and more than a few debates) that occcured at the time.  Many design charettes were held around the state to largely skeptical audiences of engineers and other technical professionals. Those of us involved were careful to describe the VRRM as a “compliance tool,” and not “a model.”

Both compliance tools and models – in their best sense -- are based on a good understanding of the state of the science. In addition, a compliance tool sends certain signals to the development community.  If a design engineer selects design approach X versus Y, then compiance is either easier or harder. These signals are very important to consider when developing such a tool in order to achieve desired outcomes: less runoff, more treatment, less soil compaction, more vegetation, etc. and, importantly, to avoid unintended outcomes.  In addition, a compliance tool should be crafted to be usable and understandable for every regulated development/redevelopment site across the Commonwealth.

Those of us in the Bay Watershed now live in a compliance world governed by the CBWM, so the line between a model and compliance tool have been blurred.  However, the VRRM will still function in essence as a compliance tool. If adding impervious cover vis-à-vis turf leads to a better compliance outcome for the designer, then that is what will happen at site after site.  While it is accurate that recent data indicate that direct phosphorus wash-off loads from impervious are lower than documented in older studies (e.g. NURP), adding more impervious will simply exacerbate the downstream watershed and stream channel issues that are very well documented in the Impervious Cover Model and other studies, thus undermining key objectives of the Virginia Stormwater Management Program.  

Recommendation: In addition to the helpful modelled scenario runs presented in the VRRM Version 4.1 cover memo, allow a period of provisional testing at real development sites to evaluate outcomes and any unintended consquences (e.g., more high impervious cover sites than Version 3.0).  Adjustments can be made while still maintaining consistency with CAST.

Continue to Conduct a VRRM Update

The VRRM integrates (1) loading rates and reductions necessary to reach site-based load targets, (2) runoff coefficient values, and (3) runoff reduction, pollutant removal, and mass load removals for various BMPs. All three of the components listed above should be based on a thorough anlaysis of the current state of the science.

The VRRM Version 4.1 update addresses #1 and some of #2, as long as CAST represents the state of the science (although all would acknowledge that the CBWM also includes a measure of approximation and stakeholder compromise).  As for Rv values, interesting research on the affects of soil compaction is being conducted at the Center for Urban & Environmental Research at UMBC, Penn State, and other institutions in addition to work in Arlington County concerning on-lot runoff (mentioned below).  This research is leading to the conclusion that compacted soil in urban environments is a source of “hidden impervious cover.”  While the research in its current state may not be ready for regulatory adoption, it certainly represents an updated understanding of the state of the science.  It is interesting to note that the increased Rv/CNs values for Managed Turf in the VRRM 4.1 support this finding (tempered by the fact that the P-ban assumption reduces the 4.1 Managed Turf loading rates from 4X to 1.4X compared to Version 3.0).

As for BMP runoff reduction (RR) and pollutant removal (PR) efficiences, the updated VRRM does not change these.  It must be said that the original rates were based on research conducted up through, at the latest, 2007, and much additional BMP research has been done since that time.  More recent studies have been conducted that ties design parameters for certain BMPs to RR and PR rates.  I led teams for two of these efforts that used updated research through 2017 (see attached reports from Metro Nashville and DOEE). And, indeed, there has been additional research since that time. 

Not including a more robust effort to assemble the state of the science on all components of the VRRM would be a missed opportunity.

Recommendation: Refrain from referring to the current effort as “updating” the VRRM but rather integration with CAST/CBWM with further work needed for a true update.  In the near future, mount an effort to truly update the state of science for each VRRM component.    

New Development & Redevelopment Land Is Different Than General Watershed-Wide Land Covers

The integration with CAST and the CBWM to derive new loading rates (and P targets) is justified.  However, the VRRM was developed for very specific categories of land use: new development and redevelopment subject to the VSMP regulations.  These land uses do not behave like general watershed land covers.  Development sites are often mass-graded, topsoil stripped, and the soil compacted in many areas.  In addition, stabilization techniques like hydroseeding use higher fertilizer rates, which are needed to establish new vegetation.  The upshot is that new development and redevelopment sites are likely to have higher runoff volumes (e.g., due to compaction and mass grading) and nutrient loads. 

One could argue that all urban land cover categories in CAST have undergone similar site grading at some point in time.  However, a recent study in Arlington County found that newly-developed lots are 10X more compacted than older lots.  The County now requires soil profile rebuilding in order to address the excessive runoff generated by new development.

Recommendation: A literature search of runoff volumes and nutrient loading from the post-construction condition at development sites may yield certain adjustments for runoff and loading.

Mixed Open Land Cover

Other commentors (e.g., HRPDC) have better insights on the MO category, and I defer to those recommendations.  It seems methodology-wise, there was rigor applied to to developing MO loading rates and Rv values.  However, my concern rests with how this will be interpreted in the real world of plan review and project construction.  There will certainly be an incentive for designers to use MO in lieu of Managed Turf, so verification during construction and through time will be essential.

In addition, I question I inclusion of MO in the Drainage Area tabs of the spreadsheet.  With the original VRRM, Forest/Open Space was not included in the Drainage Area tab because it seemed misguided to have development sites build BMPs to treat this type of land cover (or, worse, cut down trees to build BMPs to treat the remaining forest).  I question whether the same logic should apply to the new MO category, if it truly is meant to remain undisturbed.  Our emerging understanding of forests, undisturbed open space areas, and the like are that they are BMPs unto themselves, and the VRRM intentionally provides incentives to preserve as many of these features as possible from the pre-development condition.  In this regard, Clearinghouse BMPs should still focus on treating runoff from impervious and managed turf land covers.  

An additional recommendion is, if the MO category remains in the VRRM, use it instead of Forest for the surface area of qualifying BMPs (those that are vegetated and don’t replace an otherwise impervious surface).  Version 3.0 allows these surface areas to be classified at Forest/Open Space, but the MO designation may be more applicable for these structural BMPs.

Recommendation: As suggested by HRPDC, provide clarity on MO conditions, consistent application, and verification through deeds or easements, as currently done for Forest/Open Space.

Overall

The consistent themes of these comments is to base VRRM updates on the thorough and updated analysis of the state of science that underpins the loading rates, Rv values, and BMP mass load removal rates.  In addition, review the modified VRRM as it applies to results at actual development sites to identify and rectify unanticipated real-world outcomes.  

Once again, thank you for this opportunity to submit comments on the VRRM.

Sincerely,

David J. Hirschman, Principal, Hirschman Water & Environment, LLC

Appendix A, Section A5.4.  Specifically notes that no more than +/- 10% of an existing drainage area may be moved to another drainage area.  It is quite often that we are creating flat land where land is undulating.  It would be better to simply apply energy balance to each outfall.  There seems to be no explanation for this and it seems arbitrary.  If 10 % then why not 7.546%.  Or 50%.  

It appears you are administratively changing the pollutant load from 0.41 to 0.26 pounds per year.   State Code specifically lists the pollutant load as 0.41 pounds of phosphorus per year.  Would the General Assembly need to change this?

This change will make development extremely difficult to gain compliance.  You are practically doubling the pollutant load.  Are you going to double the amount of nutrient credits we can use?  Many of us have purchased land with the intention of developing.  This change will lower density and increase development costs.  Effectively you are devaluing our investment.

As a member of the VESMH SAG, we were given early review of these changes.  I provide example projects that showed that large lot residential, parks and even early grading plans would have a greater pollutant load reduction while industrial, commercial and urban residential would have less pollutant load reductions. 

Utilizing BMPs to treat impervious cover also showed diminishing returns with the lower pollutant loads. Meaning that some BMPs have to treat more pervious lawns which could increase the maintenance burden.  Imagine permeable pavement or bioretention be used to treat your lawn and then getting clogged more frequently with leaves and sediments.  

The science for the reduction of impervious surface loadings was not presented to us.  It appears that the impervious surface loadings only looked at rooftop runoff and not pavement associated with parking lots and roads.  Roads and parking lots make up the majority of impervious cover. 

Of course there is very little atmospheric deposition of phosphorus, phosphorus is sediment bound.  The greatest source of phosphorus on impervious surfaces comes from leaf litter, grass clippings and sediment deposition.  This has not changed since the 1970s research of University of Wisconsin and other institutions which led to the development of the Simple Method.   

Taking the simple method out of the VRRM makes engineers and water quality professionals more reliant on the spreadsheet and the CAST model.  

Lastly, as noted by others, DEQ may not even have the authority to make these changes since they effectively reduce the target pollutant load from 0.41 lbs/acre to 0.26 lbs/acre.  Regardless of how it is balanced.

Thank you for your consideration.

Richard Jacobs, P.E.

I wanted to offer my support for the comments presented by the engineers, developers, and contractors on the proposed Virginia Runoff Reduction Method Compliance Spreadsheet User’s Guide & Documentation (Version 4.1, July 2024 Guidance Document. 

Specifically on changes that add additional cost to projects and time it takes for plan approval. The increases in development cost get passed directly to the buyer and consumer. Affordable housing has become less affordable today due to inflation and the current housing shortage. Builders are struggling to keep up with current demand and these policies proposed here will add additional cost to each unit being sold. 

I propose putting a hold on any policy change that will add additional cost and burden on all projects, specifically residential developments.